EP3938578A1

EP3938578A1 - Method for compacting a ballast bed of a track

Info

Publication number: EP3938578A1
Application number: EP20705332.3A
Authority: EP
Inventors: Gerard Lintz
Original assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Current assignee: Plasser und Theurer Export Von Bahnbaumaschinen GmbH
Priority date: 2019-03-14
Filing date: 2020-02-12
Publication date: 2022-01-19
Anticipated expiration: 2040-02-12
Also published as: EP3938578B1; WO2020182393A1; AT522237B1; EP3938578C0; AT522237A1

Abstract

The invention relates to a method for compacting a ballast bed (5) of a track (4) in layers by means of a track construction machine (1) travelling on the track (4), wherein ballast located below sleepers (6) of the track (4) are compacted in at least two layers (20, 21) lying on top of one another, whereby a lower ballast layer (20) is compacted in a first compacting step and subsequently an upper ballast layer (21) above the lower ballast layer (20) is compacted by a tamping process in a second compacting step. Before the compacting, the lower ballast layer (20) and the upper ballast layer (21) are introduced onto the track (4) together, wherein in the first compacting step, vibrating tamping tines (10) of a tamping assembly (7) arranged on the track construction machine (1) are lowered in such a way that tamping tine plates (16) arranged on the free ends of the tamping tines (10) penetrate into the lower ballast layer (20) and held there, vibrating in position, for a predefined time period, and wherein in the second compacting step, the vibrating tamping tines (10) with the tamping tine plates (16) penetrate into the upper ballast layer (21) and are moved towards one another. In this way, a consistently good compacting can be provided for the entire ballast layer located below the sleepers (6).

Description

Method for compacting a ballast bed of a track

Field of technology

[01] The invention relates to a method for compacting a layer by layer

Ballast bed of a track by means of one moving on the track

Track construction machine, where ballast located below sleepers of the track is compacted in at least two superimposed layers by compacting a lower ballast layer in a first compacting step and then in a second compacting step an upper ballast layer lying above the lower ballast layer is compacted by a tamping process.

State of the art

From AT 518324 A1 a generic method is known with which a ballast bed of a track is compacted in layers. In a first compaction step, a compaction unit is used in which horizontally aligned compaction plates are lowered between sleepers of the track. There the compaction plates press on an exposed lower ballast layer and compact it. Then an upper layer of gravel is applied and compacted by a tamping process. In this way, ballast is gradually applied, leveled and compacted under the raised track.

Summary of the invention

[03] The invention is based on the object of providing a method, which is simplified compared to the prior art, for compacting a layer by layer

To indicate the ballast bed.

According to the invention, this object is achieved by the combination of features according to claim 1. Dependent claims indicate advantageous embodiments of the invention. [05] It is provided that before compaction, the lower ballast layer and the upper ballast layer are introduced together into the track, that in the first compression step vibrating tamping picks are placed on the

The tamping unit arranged on the track construction machine is lowered in such a way that the tamping ax arranged at the free ends

Penetrating tamping plates penetrate into the lower gravel layer and are kept vibrating in position there for a predetermined period of time, and that in the second compaction step, the vibrating tamping tine with the

Tamping picks penetrate the upper layer of ballast and are placed together. It is essential that there is no order movement during the first compression step. The structure of the gravel grains is compacted, but not shifted. At the same time, the structure of the ballast grains in the upper layer is compacted and shifted during the second compaction step. In this way one results for the entire ballast layer located below the sleepers

consistently good compression. The present invention is particularly useful in the area of switches because there the simultaneous introduction of the ballast layers reduces the technical effort.

[06] It is advantageous if between the first and the second

Compaction step further ballast is introduced into the track. This additional ballast is initially deposited between and on the sleepers. During the second compression step, the from the

Ballast compaction resulting volume changes in the

Ballast layers balanced.

[07] An advantageous development of the invention provides that during the second compression step the track is held in a target position by means of a lifting / straightening unit. In this way, the track position is corrected. This creates cavities under the sleepers during a lifting process. The provision of the vibrating tamping ax causes the ballast to be shifted into these cavities.

[08] It can be the case with new track layers or generally with a soft ballast bed

make sense if the tamping tines are lowered twice in a row during the second compaction step. Each time a Order the vibrating tampons. Such repetition of the stuffing cycle is appropriate when only one stuffing cycle is not optimal

Packing density of the ballast is achieved.

[09] The lower ballast layer and the upper

Ballast layer with a total layer height of at least 200 mm. The lower and upper gravel layers each reach a height of approximately 100 mm. With these layer heights, the present method delivers particularly good compaction results.

In the first compaction step, it is beneficial if the tamping tine plates penetrate completely into the lower ballast layer up to at least 100 mm below the lower edge of the sleeper. This ensures that the entire compaction energy acts on the ballast grains of the lower ballast layer.

[11] Another improvement of the first compression step provides that the vibrating tamping tines are held in position for a period of time between 1 second and 2 seconds in the lowered state. The

The duration of the vibrating tamping ax is then sufficient to optimally compact the gravel structure in the lower gravel layer.

[12] It is also advantageous if the

Vibrate tampons at a frequency in the range 35Hz to 45Hz. This frequency range delivers the best compaction results.

Advantageously, the tampons vibrate at a higher frequency when penetrating than in the lowered position. The one with the higher points

Gravel vibrated at a lower frequency

Resistance to penetration.

In an advantageous extension of the method, the ballast bed is compacted after the second compaction step in a further compaction process by means of a stabilization unit. The stabilization process shakes the track grid consisting of sleepers and rails into the

Gravel bed. In this way, subsidence of the track grid that occurs after the tamping process is anticipated. Immediately after one of these

Processing is driving on the track with a higher

Speed allowed. The method is particularly effective when the track-laying machine is operated in association with a cleaning machine and when the lower ballast layer and the upper ballast layer are connected to one another

Cleaning machine arranged throwing device are introduced. The result of the treatment with the cleaning machine is a soft ballast bed that is continuously compacted with the two compaction steps.

Brief description of the drawings

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

Fig. 1 track construction machine

Fig. 2 tamping unit

Description of the embodiments

The track construction machine 1 shown in FIG. 1 can be moved on rails 3 of a track 4 by means of rail bogies 2. The rails 3 are attached to sleepers 6 mounted in a ballast bed 5. To carry out the present method, the track construction machine 1 comprises a tamping unit 7. In addition, a lifting / straightening unit 8 and a measuring system 9 are arranged for a track position correction.

[17] Compared to conventional tamping units, the present

Tamping unit 7 longer tamping pick 10 on. The tampons 10 are

arranged opposite one another in order to penetrate the ballast bed 5 on both sides of a sleeper 6 during a compression step. These are the

opposite tamping ax 10 with associated swivel arms 11 mounted on a height-adjustable tool carrier 12. A hydraulic cylinder, for example, serves as the height adjustment drive 13.

The swivel arms 11, which are arranged like pliers, are coupled to a vibration generator 15 via a respective auxiliary cylinder 14. This

Vibration generator 15 comprises, for example, an eccentric shaft driven in rotation. To transmit a vibration, the respective Additional cylinder 14 connected on the one hand to the eccentric shaft and on the other hand to an upper end of the associated swivel arm 11.

In the first compression step according to the invention, the respective

Additional cylinder only as a rigid transmission element. In the ratio of the lever arm lengths of the respective swivel arm 11, the eccentricity of the eccentric shaft results in a vibration amplitude at the free end of the associated tampon 10. A tampon plate 16 is arranged there at the end of a narrow tampon shaft. The respective tamper plate 16 is aligned normal to the direction of a vibratory movement 17. In this way, during the first compression step, all of the

Tamping pick plate 16 captured gravel grains set in vibration.

[20] The auxiliary cylinders 14 are only actuated in the second compression step.

By acting on the respective auxiliary cylinder 14, the

Vibration movement 17 is superimposed on a positioning movement 18. In the process, the vibrating tamping pick plates 16 are moved towards one another, as a result of which the captured ballast grains are set in vibration and additionally displaced.

[21] An exemplary process sequence begins with 4 ballast being introduced into a track. This happens either when the track 4 is re-laid or when the ballast is cleaned using a cleaning machine. The ballast is introduced below the sleepers 6 with a

Total layer height 19 at which a normal tamping process does not produce sufficient compaction. Therefore a lower one first

Ballast layer 20 and then an upper ballast layer 21 compacted.

According to the invention, the lower ballast layer 20 and the upper ballast layer 21 are introduced into the track 4 at the same time before the compaction.

The first compression step then takes place. In particular in the case of switches or crossings, the simultaneous introduction of both ballast layers 20, 21 is advantageous. In the case of switches or crossings, the track grid cannot be laid on the lower ballast layer 20 before the upper ballast layer 21 is introduced, as is the case with a line track, in order to make this layer 20 in

conventional way to compact. At the beginning of the first compression step, the tamping unit 7 is positioned above a threshold 6 (middle threshold in FIG. 2). Using the

Height adjustment drive 13, the vibrating tamping ax 10 are lowered and dive into the ballast bed 5. The tamping tines ideally vibrate at a frequency of approx. 45 Hz. With this frequency, those in

Gravel grains vibrated in a flowing medium, which significantly reduces the penetration resistance.

A first countersinking depth 22 is specified in such a way that the tamping tine plates 16 pass entirely into the lower gravel layer 20. In FIG. 2, the tamping tines 7 with the tool carrier 12 raised are shown as a reference above the right sill 6. When the first lowering depth 22 is reached, the distance between an upper edge of the respective

Tamping pick plate 16 and a lower edge of the respective threshold 6, for example 100 mm. From the known heights of the sleepers 6 and the rails 3 as well as the geometry of the track construction machine 1, a corresponding specification for controlling the height adjustment drive 13 results for a control device 23. The first lowering depth 22 is limited by a formation protection layer 24, which may be located under the lower one

Gravel layer 20 is located. Care should be taken that the

The formation protection layer 24 is not damaged by the tamping ax 10.

As soon as the predetermined first lowering depth 22 is reached, the

vibrating tamping ax 10 held in position for a predetermined period of time. The vibration is transmitted to the surrounding gravel with a frequency of approx. 35 Hz. For example, the speed of rotation of the eccentric shaft is adapted accordingly. In this vibrating state, the ballast grains arrange themselves under the load of the upper ballast layer 21 to form a denser structure. Ideally, the specified time span is approx. 1.5 seconds. A sufficient degree of compaction of the ballast structure is then achieved and the tamping picks 10 are pulled out of the ballast bed 5 by acting on the height adjustment drive 13.

[26] This first compression step is for all sleepers 6 of the to

processed track section, switch or crossing repeatedly. Subsequently track 4 is ballasted if necessary. This introduction of additional ballast is particularly useful if the track grid is to be raised in the subsequent second compaction step.

The second compression step begins with a positioning of the

Tamping unit 7 above a threshold 6 with an already compacted lower gravel layer 20 (left threshold in FIG. 2). If a correction of the track position is planned, the lifting / straightening unit 8 is activated. The track grid is lifted into a predetermined position and shifted to the side if necessary. This corrected position is then fixed immediately by means of the tamping unit 7.

The tool carrier 12 is lowered until the tamping tine plates 16 reach a second lowering depth 25. The distance between the upper edge of the respective tamping plate 16 and the lower edge of the respective threshold 6 is a few centimeters (e.g. 20 cm). This second lowering depth 25 can also be predetermined for the control device 23 on the basis of the known threshold height, the rail height and the machine geometry.

[29] After the second lowering depth 25 has been reached, the tamping tine plates 16 opposite one another are placed together. The positioning movement 18 combined with the vibration movement 17 causes a displacement of the

Ballast grains in the area below the threshold 6. The result of the ballast grains set in vibration and displaced is a compacted ballast structure. In this way, with the already compacted lower gravel layer 20, overall a stable support for the respective sleeper 6 is created.

[30] In the case of a new track, it can happen that after an initial

Ordering process there is still no optimal compression of the upper ballast layer 21. Then the tampons 10 are again in the upper

Ballast layer 21 immersed and provided to one another. Such a repetition is decided by an operator or by recording the state of the ballast by means of sensors arranged on the track construction machine 1. For example, counterforces acting on the tamping ax 10 are used to determine a parameter for the ballast compaction.

[31] The workflow described is completed by using a so-called dynamic track stabilizer (DGS). Is to For example, a stabilization unit is arranged on the same track construction machine 1. Alternatively, track 4 is driven on by means of a separate stabilization machine.

Claims

Patent claims

1. A method for layer-by-layer compression of a ballast bed (5) of a track (4) by means of a track construction machine (1) moving on the track (4), with ballast located below sleepers (6) of the track (4) in at least two superimposed layers (20, 21) is condensed by adding a first

Compacting step, a lower ballast layer (20) is compacted and then in a second compacting step an upper ballast layer (21) lying above the lower ballast layer (20) is compacted by a tamping process, which means that the lower ballast layer prior to compaction (20) and the upper ballast layer (21) are introduced together into the track (4) that in the first compression step vibrating tamping picks (10) of a tamping unit (7) arranged on the track construction machine (1) are lowered in such a way that the free ends of the tamping tines (10) arranged tamping tine plates (16) penetrate into the lower gravel layer (20) and are kept vibrating in position there for a predetermined period of time, and that in the second compaction step the vibrating tamping tine (10) with the tamping tine plates (16) in penetrate the upper gravel layer (21) and be provided to each other.

2. The method according to claim 1, d ad u rch geken nzeich net that further ballast is introduced into the track (4) between the first and second compression step.

3. The method according to claim 1 or 2, d ad u rch geken nzeich net that the track (4) is held in a target position by means of a lifting / straightening unit (8) during the second compression step.

4. The method according to any one of claims 1 to 3, d ad u rch geken nzeich net that the tamping pick (10) twice during the second compaction step

be lowered one after the other.

5. The method according to any one of claims 1 to 4, d ad u rch geken nzeich net that the lower ballast layer (20) and the upper ballast layer (21) with a

Total layer height (19) of at least 200 mm must be introduced.

6. The method according to any one of claims 1 to 5, d ad u rch geken nzeich net that in the first compression step the tamping plates (16) completely penetrate up to at least 100 mm below a threshold lower edge in the lower gravel layer (20).

7. The method according to any one of claims 1 to 6, d ad u rch geken nzeich net that during the first compression step the vibrating tamping tines (10) are held in position in the lowered state for a period of time between 1 second and 2 seconds.

8. The method according to any one of claims 1 to 7, d ad u rch geken nzeich net that during the first compression step, the tamping tines (10) vibrate at a frequency in a range from 35Hz to 45Hz.

9. The method according to any one of claims 1 to 8, d ad u rch geken nzeich net that the ballast bed (5) after the second compaction step in a further

Compaction process is compacted by means of a stabilization unit.

10. The method according to any one of claims 1 to 9, d ad u rch geken nzeich net that the track construction machine (1) is operated in association with a cleaning machine and that the lower ballast layer (20) and the upper ballast layer (21) with a be introduced to the cleaning machine arranged throwing device.