EP3902956B1 - Method and track laying machine for processing a ballasted track - Google Patents

Description

field of technology

The invention relates to a method for processing a ballast track by means of a track construction machine, which comprises a lifting unit with holding rollers for holding a track grate formed from rails and sleepers and with lifting drives for lifting the track grate and a measuring system for comparing with a target position of the track, wherein the The lifting unit is caused to vibrate by means of a vibration exciter and the vibration is transmitted to the track grate. The invention also relates to a corresponding track construction machine.

State of the art

From the WO 2017/092840 A1 A tamping machine is known which has a lifting and straightening unit that can be set in vibration by means of a vibration exciter. The machine is used to carry out a process in which a track is processed in two work passes. In a first work pass, the track is raised to a target level in a conventional manner using the lifting and straightening unit and tamped using tamping units. During this lifting and straightening process, the vibration exciter of the lifting and straightening unit remains switched off. In a subsequent work pass, the tamping machine travels the same track section a second time. The vibration exciter is activated and the lifting and straightening unit is used as a stabilization unit.

Out of AT 400 862 B a method for processing a ballast track using a track-laying machine is known, wherein the track-laying machine has a lifting unit with holding rollers for holding a track grate formed from rails and sleepers and with lifting drives for lifting the track grate, a control device and a measuring system for comparing with a target position of the track includes. The lifting unit is caused to vibrate by means of a vibration exciter and the vibration is transmitted to the track grate.

Summary of the invention

The invention is based on the object of improving track processing by means of a lifting unit of the type mentioned at the beginning. In addition, a track construction machine optimized for the improved process should be specified.

According to the invention, these tasks are solved by the features of claims 1 and 7. Advantageous developments of the invention result from the dependent claims.

The lifting unit is controlled by means of a control device in such a way that during a lifting process, the lifting unit is set into vibration and the track grate is first raised above the target position and then lowered to the target position. In the effective area of the lifting unit, cavities initially arise under the sleepers when lifting. These are filled with ballast during the lifting process because the vibrations transmitted to the track grate put the ballast in a flow-like state. In particular, the gravel grains located next to and on the sleepers start to move and migrate downwards into the resulting cavities. This combined lifting and oscillating movement takes place beyond the target position so that enough gravel gets under the sleepers. To reach the target position, the oscillating lifting unit is then pushed down. The gravel that gets into the cavities is compacted and forms a stable support for the sleepers. Horizontal vibrations in the transverse direction of the track are advantageously transmitted to the track grate in order to achieve effective compaction of the ballast. With the method according to the invention, the track grate can be raised in a simple manner while at the same time stabilizing the track position.

In an improved variant of the method, the lifting process is interrupted at least once by lowering the oscillating lifting unit. This leads to a pre-compaction of the ballast that has already been moved under the sleepers. This increases the void volume under the sleepers as the lifting process continues, allowing more gravel to get under the sleepers throughout the entire lifting process.

A further development of the method provides that the lifting unit includes straightening drives by means of which the track grate is straightened and that the vibration of the lifting unit is reduced during a straightening process. In this form, the lifting unit fulfills the functions of a lifting and straightening unit. During lifting and lowering movements, disruptive effects of the vibrating unit on a machine frame are negligible because the movably mounted height drives have a vibration-damping effect. The situation is different with a directional movement that occurs in the transverse direction of the track. When the straightening drives are activated, the lifting unit cannot oscillate freely in the cross-track direction because straightening forces act between the lifting unit and the machine frame. Disturbing vibration transmission to the machine frame is prevented by reducing the vibration of the lifting unit. Ideally, vibrations are completely switched off while the straightening drives are activated.

In an advantageous extension of the process, gravel is applied to the track grate in a previous work process. This is done either with the same track-laying machine or with another machine, for example a ballast plow. In particular, the ballast placed on the sleepers is set in motion by the transmitted vibrations and fills the depressions and cavities created during the lifting process. In this way, there is enough subsequent gravel available for the filling processes in order to achieve high lifting values with the present method.

It is beneficial if new or cleaned ballast is placed on the track grate. The high-quality gravel is initially very mobile and promotes the shifting of the vibrating gravel grains. After compaction, however, there is a very stable structure that is not affected by any contamination or abrasion. This achieves the desired high transverse displacement resistance of the sleepers embedded in the ballast.

A further improvement provides that in a subsequent operation, sleepers of the track grate are tamped using a tamping unit. The ballast, pre-compacted by the vibrating lifting unit, is brought under the respective threshold even more efficiently using the tamping unit. The lifting unit holds the track grate in the desired position. By pre-compacting the gravel, the opposite is achieved Conventional tamping processes achieve better compaction with fewer tamping cycles.

The track construction machine according to the invention for processing a ballast track comprises a lifting unit with holding rollers for holding a track grate and with lifting drives for lifting the track grate, the lifting unit being coupled to a vibration exciter. The machine also includes a measuring system for comparing the lifting level during a lifting process with a target position of the track. In addition, a control device is arranged which is set up to control the lifting unit according to one of the methods described. This new control of the lifting unit enables the gravel to be compacted or pre-compacted during a lifting process.

According to the invention, the vibration exciter comprises an adjusting device for adjusting an impact force acting on the track grate by the lifting unit. This means that the vibration transmitted to the track grate can be adapted to the given requirements. Particularly during a straightening process, it makes sense to reduce the transmitted vibration to reduce the impact force. In addition, the adjustable impact force can be used to lower the track grate in a controlled manner. With the same load, a stronger impact force leads to a faster sinking of the track grating.

In a further advantageous embodiment, a tamping unit is arranged on a machine frame or a satellite frame behind the lifting unit with respect to a working direction. This enables multi-stage compaction in one work trip, with the lifting unit causing pre-compression and the tamping unit causing additional compaction.

Another advantageous embodiment provides that a stabilization unit is arranged behind the lifting unit with respect to a working direction. Such a combination is beneficial for new track laying or after ballast cleaning. The track is raised to a desired target position and pre-compacted using the measuring system and the vibrating lifting unit. The gravel is then further compacted using the stabilization unit. With this layered Compression and simultaneous position correction, driving clearances up to a specified permitted speed are possible even without the use of a tamping unit.

Brief description of the drawings

Fig. 1

Gleisbaumaschine mit Hebeaggregat und Stopfaggregat

Fig. 2

Gleisbaumaschine mit Hebeaggregat und Stabilisationsaggregat

Fig. 3

Gleisbaumaschine mit einem Satellitenrahmen

Fig. 4

eingeschotterter Gleisrost in einem Längsschnitt

Fig. 5

Gleisrost gemäß Fig. 4 während einer Gleisrostanhebung

Fig. 6

Gleisrost gemäß Fig. 4 während einer Gleisrostabsenkung

Fig. 7

Bewegungsverlauf während eines Hebevorgangs

The invention is explained below in an exemplary manner with reference to the attached figures. It shows in a schematic representation:

Fig. 1

Track construction machine with lifting unit and tamping unit

Fig. 2

Track construction machine with lifting unit and stabilization unit

Fig. 3

Track construction machine with a satellite frame

Fig. 4

Ballasted track grid in a longitudinal section

Fig. 5

Track grid according to Fig. 4 during a track grating lift

Fig. 6

Track grid according to Fig. 4 during a lowering of the track grid

Fig. 7

Movement progression during a lifting process

Description of the embodiments

The track construction machine 1 in Fig. 1 comprises a machine frame 2, which is mounted on rail chassis 3 and can be moved on a track 4. The track 4 is a ballast track in which sleepers 6 mounted on ballast 5 and rails 7 connected to them form a track grate 8. With respect to a working direction 9, a tamping unit 11 is arranged behind a lifting unit 10. A measuring system 12 includes, for example, three measuring cars 13, which record a track position during processing compared to a reference system 14. Either mechanically tensioned measuring gauges or optical devices are used as the reference system 14.

A mechanical measuring system 12 includes two leveling chords (one for each rail) and a directional gauge. The tendons are stretched between the two outer measuring cars 13 and there is a measuring sensor 15 on the middle measuring car. In an optical measuring system 12, light sources and optical sensors are arranged on the measuring cars 13, by means of which the positions of the measuring cars 13 relative to one another are recorded. In the present invention, the measuring system 12 is used to measure the track grate 8 to be raised to a desired level by means of the vibrating lifting unit 10.

According to the invention, the lifting unit 10 comprises a vibration exciter 16. This is preferably constructed in such a way that the lifting unit 10 is set into a horizontal vibration transversely to the longitudinal direction of the machine when the vibration exciter 16 is activated. For example, two rotating unbalances are arranged, the impact forces of which increase in the horizontal direction and cancel out in the vertical direction. It is advantageous if the resulting impact force can be adjusted. For this purpose, either at least four unbalances with mutually adjustable phase positions or unbalances with adjustable eccentricity of the center of mass are provided. With the adjustable impact force, the vibration of the lifting unit 10 can be adapted to optimized specifications without delays.

To lift the track grate 8, the lifting unit 10 includes holding rollers 17, which hold the rail heads in place and can be rolled along the rails 7. Flanged rollers and rollers arranged on rolling tongs are used as holding rollers 17. The wheel flange rollers are pressed against the inner edges of the rails using telescopic axles. The rolling tongs grip the rail heads from the outside.

By means of the holding rollers 17, all movements of the lifting unit 10 are transferred to the held track grate 8. To raise and lower the track grate 8, the lifting unit 10 includes lifting drives 18, which are connected to the machine frame 2 and can carry out lateral pendulum movements. As a result, the horizontal vibration of the lifting unit 10 is not transmitted to the machine frame 2.

It makes sense that the lifting unit 10 also fulfills the function of track straightening. The track 4 is brought laterally into the desired target position. When actuated, the straightening drives 19 required for this cause the lifting unit 10 to shift laterally relative to the machine frame 2. During a straightening process, there is therefore a lateral force transmission between the lifting unit 10 and the machine frame 2. In order to avoid disruptive vibration transmission to the machine frame 2 To avoid this, the vibration exciter 16 is deactivated during track straightening. It is also sufficient to reduce the impact force by adjusting the imbalances that cause vibration.

The lifting unit 10 is controlled with a control device 20. A control sequence for the lifting unit 10 is set up in this control device 20. When the process is activated, at least in one process phase, the vibrating lifting unit 10 is raised above a target position of the track 4. The current position of the track grate 8 during the lifting process is compared with the target position using the measuring system 12.

The Figures 2 and 3 show further advantageous characteristics of a track construction machine 1, by means of which the method according to the invention can be carried out in an optimized manner. In Fig. 2 A stabilization unit 21 is arranged behind the lifting unit 10 in the working direction 9. This ensures continuous track processing. After the track has been raised using the lifting unit 10, the track 4 is stabilized using the stabilization unit 21.

The track construction machine 1 in Fig. 3 is designed as a continuously working tamping machine. The machine 1 moves continuously along the track 4. A satellite 22 with the lifting unit 10 and the tamping unit 11 is moved cyclically forwards and backwards relative to the machine frame 2 in order to position the tamping unit 11 above the respective threshold 6 for the tamping process.

The operation of the lifting unit 10 is based on the further Figures 4-7 explained. At the beginning, the track grate 8 is covered with gravel 5 ( Fig. 4 ). For example, gravel 5 was moved from the side of an embankment towards the rails 7 using a gravel plow. While the machine is moving forward, the track grate 8 is lifted by means of the lifting unit 10 which is set in vibration, with the vibrations being transmitted to the ballast 5. From an oscillation frequency of approximately 30 Hz, the vibrating gravel 5 shows a behavior similar to that of a flowing medium. That's why the cavities that appear during during the lifting process under the sleepers 6, immediately filled with moving gravel grains ( Fig. 5 ).

A subsequent downward movement of the lifting unit 10, which continues to vibrate, causes the ballast 5 moved under the sleepers 6 to be compacted ( Fig. 6 ). Compared to a conventional stabilization unit 21, a lower impact force is sufficient. Smaller imbalances are therefore provided in the vibration exciter 16 than in a stabilization unit 21. A vibration frequency in a range of 35 Hz to 50 Hz is optimal both during the lifting process and during the downward movement.

The invention extends to several working methods with and without a tamping unit 11. When using the lifting unit 10 as a lifting and straightening unit during a tamping process, the following process steps are used. At the start of work, the lifting unit 10 is lowered onto track 4. The wheel flange rollers are pressed apart using telescopic axles and the rolling tongs are pressed onto the rails 7. The vibration exciter 16 is then activated and the lifting unit 10 and the held track grate 8 begin to vibrate. The lifting unit 10 is initially held in position via the measuring system 12 in order to avoid unintentional lowering of the track 4.

During a right-of-way with the track-laying machine 1, the lifting unit 10 with the track grate 8 held in place is raised several times and lowered in between. This pulsating lifting process is carried out by means of the lifting drives 18, with the measuring system 12 being used to continuously compare the current track position with a predetermined target track position.

In Fig. 7 a change in level (solid line c) of the track grate 8 during a lifting process in the vertical direction z is shown over time t. During the duration d of a lifting process, the track grate 8 should be lifted from a starting position a with a lifting value h to a predetermined target level b. The target level b corresponds to the target position of track 4 in the vertical direction z. With the further forward movement of the Machine 1, the lifting unit 10 follows the course of the track grate and, starting from the starting position a, a new lifting process begins.

In this example, the track elevation is divided into three sections. In each section, the track grate 8 is first raised relative to a virtual linear track elevation (dashed line e). For example, a corresponding overlift value is stored in the control device 20. The aim of this elevation is to ensure sufficient placement of ballast under the raised sleepers 6. It is advantageous if the extent of the elevation can be adjusted in order to adapt to the condition of the ballast and the desired overall elevation.

The lifting process is interrupted in each section by lowering the oscillating lifting unit 10. In the first sections, it can be planned to fall below the level corresponding to a linear track lifting (dashed line e). This increases the intermediate compaction of the ballast 5 and increases the fillable cavities during the subsequent lifting of the track grating. A load can be set via the lifting drives 18, with which the lifting unit 10 presses on the track grate 8 during a lowering phase. Load, impact force and vibration frequency of the lifting unit 10 as well as the lowering duration determine the compaction of the ballast 5 under the sleepers. Adjusting these parameters leads to an optimization of the respective compaction process depending on the condition of the ballast.

At least in the last section of the lifting process, the track grate 8 is raised above the target level b with a final lowering to the target position. This is done through ongoing adjustment using the measuring system 12. In the simplest case, a straight line is specified as the target position for each rail in order to compensate for relative track position errors. An improved track position correction is achieved by specifying an absolute target position. For this purpose, the actual position is measured with respect to specified fixed points before the track is processed. Based on this, the optimal target position is derived, taking various specifications and framework conditions into account.

During the actual tamping process, the lifting unit 10 holds the track grate 8 in the position specified by the measuring system 12. The already pre-compacted gravel 5 can be brought under the sleepers 6 more efficiently using the tamping unit 11 and further compacted there. Due to the pre-compaction of the gravel 5, fewer tamping cycles are required compared to a conventional tamping process in order to achieve a predetermined degree of compaction. In addition, the combined compaction processes using the lifting unit 10 and the tamping unit 11 lead to improved compaction results.

With the present invention, it is possible to lift the track without using a tamping unit 11, particularly when laying new tracks or after cleaning the ballast. This process variant is suitable for ballast cleaning machines and track reconstruction machines. A comparison with the target position is also carried out here using the measuring system 12.

The lifting unit 10 is lowered onto track 4 at the start of work. The lifting unit 10 is connected to the track grate 8 via the holding rollers 17. The activated vibration exciter 16 causes the lifting unit 10 and the held track grate 8 to vibrate, with undesirable sinking being avoided via the measuring system 12. As soon as the track construction machine 1 moves in the working direction 9, the lifting unit 10 begins a pulsating lifting and lowering movement. As described above, the lifting process is interrupted by lowering phases. The result is a process in which lifting phases continuously alternate with lowering phases. During the lifting phases, the resulting cavities under the sleepers 6 are filled with gravel 5. This causes the track grate 8 to be raised. In the lowering phases, the ballast 5 that has reached under the sleepers 6 is compacted. In this way, the track 4 is raised to the desired position by adjusting using the measuring system 12.

The pulsating raising and lowering movement can be adjusted to the condition of the gravel and the desired elevation. The corresponding parameters such as lifting force, impact force, vibration frequency and load are set by operating personnel. Presets for these parameters can also be stored in the control device 20.

Track 4 can also be straightened. For example, the vibration of the lifting unit 10 is suspended every 1.5 to 2 meters in order to carry out a lateral displacement of the track grate 8 by means of the straightening drives 19.

In a subsequent work process, a stabilization unit 21 is used. For this purpose, several units 10, 21 can be arranged on a machine 1, as in Fig. 2 shown. Conveniently, the stabilization unit 21 can be operated with an adjustable impact force. The impact force of the stabilization unit 21 is then controlled via the measuring system 12 so that any longitudinal height errors are smoothed out. Such longitudinal height errors arise in exceptional cases due to the pulsating raising and lowering movement of the lifting unit 10. In addition, the ballast 5 is further compacted by means of the stabilization unit 21, which results in an even higher track quality.

With the method described, layer-by-layer compaction of the ballast 5 and restoration of the track geometry for driving clearances up to a certain speed can be carried out even without the use of a tamping unit 11. If necessary, the final step is processing using a tamping machine.

Claims (9)

1. A method for treatment of a ballast track (4) by means of track maintenance machine (1) which comprises a lifting unit (10) having gripping rollers (17) for gripping a track grid (8) formed of rails (7) and sleepers (6) and lifting drives (18) for lifting the track grid (8), a control device (20) for controlling the lifting unit (10) and a measuring system (12) for comparing to a target position of the track (4), wherein the lifting unit (10) is set in vibration by means of a vibration exciter (16) and the vibration is transmitted to the track grid (8), characterized in that by means of an adjustment device of the vibration exciter (16) a setting of an impact force acting by the lifting unit (10) on the track grid takes place and that the lifting unit (10) is controlled by means of the control device (20) in such a way that, during a lifting operation, the lifting unit (10) is set in vibration, and the track grid (8) is first lifted to above the target position and subsequently lowered to the target position.
2. A method according to claim 1, characterized in that the lifting operation is interrupted at least once by lowering the vibrating lifting unit (10).
3. A method according to claim 1 or 2, characterized in that the lifting unit (10) has lining drives (19) by means of which the track grid (8) is aligned, and that - during a lining operation - the vibration of the lifting unit (10) is reduced.
4. A method according to one of claims 1 to 3, characterized in that in a preceding working step, ballast (5) is placed on the track grid (8).
5. A method according to claim 4, characterized in that new or cleaned ballast (5) is placed on the track grid (8).
6. A method according to one of claims 1 to 5, characterized in that in a subsequent working step, sleepers (6) of the track grid (8) are tamped by means of a tamping unit (11).
7. A track maintenance machine (1) for treatment of a ballast track (4) according to a method according to one of claims 1 to 6, comprising a lifting unit (10) which has gripping rollers (17) for gripping a track grid (8) and lifting drives (18) for lifting the track grid (8), a control device (20) for controlling the lifting unit (10) and a measuring system (12) for comparing to a target position of the track (4), wherein the lifting unit (10) is coupled to a vibration exciter (16), characterized in that the vibration exciter (16) has an adjustment device for setting an impact force acting by the lifting unit (10) on the track grid (8).
8. A track maintenance machine (1) according to claim 7, characterized in that a tamping unit (11) is arranged rearward of the lifting unit (10), with regard to a working direction (9), on a machine frame (2) or a satellite frame.
9. A track maintenance machine (1) according to claim 7 or 8, characterized in that a stabilizing unit (21) is arranged rearward of the lifting unit (10) with regard to a working direction (9).

Images