EP3067466A1 - Machine and method for compacting a ballast bed - Google Patents

Abstract

A stuffing machine for a railroad track, the railway track comprising at least two longitudinal rails (1) extending from upstream to downstream and resting on a plurality of sleepers (2) placed on a ballast bed (3), the machine comprising at least one vibratory tamping arm (4) adapted to be immersed vertically in the depth of the ballast bed (3) between said longitudinal rails (1) and said crosspieces (2) and at least one plating member (5) vibrating in a horizontal plane adapted to be applied to the surface of the ballast bed (3), between said longitudinal rails (1) and said crosspieces (2), close to said vibrating stuffing arm (4) so as to facilitate diving said vibrating tamping arm (4) in the depth of said ballast bed (3).

Description

GENERAL TECHNICAL FIELD AND PRIOR ART

The present invention relates to the field of tamping and compacting the ballast of a railway track.

In known manner, a railway track comprises at least two longitudinal rails connected by transverse cross members resting on a ballast bed adapted to distribute the mechanical forces received by the railway during the circulation of a railway vehicle. Following the passage of railway vehicles on a railway track, it is necessary to correct its geometry periodically.

For this purpose, it is known to use a stuffing machine, also called tamper, which allows to position / orient the rails to correct the geometry and freeze this geometry by compacting the ballast under the rail sleepers. A tamping machine comprises vibrating tamping arms, also called tampers, adapted to be immersed in the ballast bed upstream downstream of the cross member whose ballast must be compacted. The stuffing arms are then brought together in order to clamp the ballast under said cross member so as to freeze the position of said cross member. Such a stuffing process effectively compact the ballast under a crossbeam. In addition, such a method makes it possible to achieve a linear compaction speed (corrected number of railway track kilometers per hour) which is high.

One of the drawbacks of such a method is that it excessively solicits the ballast, in particular during the step of dipping the stuffing arms. In practice, after several implementations of the compacting process, the ballast is too deteriorated (breaking of the ballast grains, blunting, etc.) and it is no longer possible to obtain sufficient compaction in order to guarantee the stability of the geometry of the rails. Also, it is necessary to replace the ballast bed, which is a significant cost both as regards the ballast itself as the resources mobilized to allow its replacement (equipment, operators, etc.).

The invention therefore aims to overcome these disadvantages by proposing a stuffing machine of new design to limit the wear of the ballast during its compaction.

Incidentally, we know from the document FR7604214 a machine to stuff the tracks and compact the ballast in front of the crossheads.

GENERAL PRESENTATION OF THE INVENTION

• au moins un bras de bourrage vibrant adapté pour être plongé verticalement dans la profondeur du lit de ballast entre lesdits rails longitudinaux et lesdites traverses et
• au moins un organe de plaquage vibrant dans le plan horizontal adapté pour être appliqué à la surface du lit de ballast, entre lesdits rails longitudinaux et lesdites traverses, à proximité dudit bras de bourrage vibrant de manière à faciliter la plongée dudit bras de bourrage vibrant dans la profondeur dudit lit de ballast.

For this purpose, the invention relates to a stuffing machine for a railroad track, the railway track comprising at least two longitudinal rails extending from upstream to downstream and resting on a plurality of sleepers placed on a bed of ballast, the machine comprising:

• at least one vibratory tamping arm adapted to be immersed vertically in the depth of the ballast bed between said longitudinal rails and said sleepers and
• at least one vibrating plating member in the horizontal plane adapted to be applied to the surface of the ballast bed, between said longitudinal rails and said sleepers, proximate said vibrating tamping arm so as to facilitate diving of said vibratory tamping arm into the depth of said ballast bed.

Thanks to the invention, the plating member makes it possible to vibrate the upper part of the ballast bed in order to lower its mechanical strength and thus facilitate the dipping of the stuffing arm which no longer wears and blunts the ballast grains. Following the action of the plating member, the upper portion of the ballast bed is "liquefied" and can be traversed easily. The life of the ballast is thus improved. The number of broken ballast grains can be halved.

Unlike a compactor, the plating member does not exert a significant mechanical pressure on the ballast bed. The plating member fluidizes the upper part of the ballast bed by means of vibrations.

Advantageously, as the plating member can be placed between the rails and between the cross members, the plating member can be located closer to the stuffing arm to facilitate its diving.

Preferably, the plating member applies a vertical pressure force of the order of 10 KN so that the vibrations liquefy the upper part of the ballast bed.

Preferably, the tamping machine comprises at least two vibrating tamping arms adapted to be immersed vertically in the depth of the ballast bed between said longitudinal rails and said crosspieces, said vibrating tamping arms being aligned laterally, the plating member is configured to vibrate along said lateral axis in the horizontal plane. Thus, the plating member can act laterally in the dipping areas of the stuffing arms. Advantageously, the plating member does not compact the ballast bed below the cross but facilitates only the dipping of the stuffing arms.

Preferably, the plating member has a flat bottom plating surface for pressing on the surface of the ballast bed. Thus, the ballast grains in contact with the plating member can transmit the vibrations optimally.

According to one aspect of the invention, the plating member has a lower plating surface having a cavity defining a plurality of reliefs. Thus, the plating member can trap ballast grains between its reliefs so as to transmit the vibrations optimally in the upper thickness of the ballast bed. Preferably, the reliefs are angular in order to improve the blocking of the ballast grains during plating and vibrating. On the contrary, curved reliefs increase the rolling of the ballast grains during vibrations, which accentuates the wear.

Preferably, the plating member has a bottom wire mesh surface to enable ballast grains to be trapped in its openings so as to transmit the vibrations optimally into the upper thickness of the ballast bed.

Preferably, the plating member has a lower plating surface covered with a deformable coating to cooperate with the ballast grains to move them optimally without rolling them relative to the plating member. Thus, the greater thickness of the ballast bed makes it possible to vibrate optimally to offer very little resistance during the dipping of the stuffing arm.

Preferably, the stuffing machine comprises at least two upstream vibrating tamping arms adapted to be immersed in the ballast bed directly upstream of a cross member, at least two downstream vibrating tamping arms adapted to be immersed in the bed of ballast directly downstream of said cross member, a vibrating veneer upstream member adapted to be applied to the surface of the ballast bed between said downstream vibrating tamping arms so as to facilitate diving of said downstream stuffer arms into the depth of said ballast bed and a downstream vibrating plating member adapted to be applied to the surface of the ballast bed between said downstream vibrating tamping arms so as to facilitate diving of said downstream tamping arms into the depth of said ballast bed.

Thus, during compacting of the ballast bed below a cross, the dive of upstream and downstream stuffing arms is facilitated by the action of the downstream and upstream plating members which limits the mechanical stresses. Also, all the vibrations of the stuffing arms contribute to compaction.

Preferably, said upstream vibrating tamping arms and said downstream vibrating tamping arms are configured to clamp the ballast bed below the cross member to compact it.

• une étape d'application d'au moins un organe de plaquage vibrant dans le plan horizontal à la surface du lit de ballast entre lesdits rails longitudinaux et entre deux traverses de manière à diminuer la résistance mécanique de la partie supérieure du lit de ballast, puis
• une étape de déplacement en plongée verticale d'au moins un bras de bourrage vibrant dans la profondeur du lit de ballast entre ledit organe de plaquage vibrant et un desdits rails longitudinaux.

The invention also relates to a method of tamping a ballast bed of a railway track by means of a stuffing machine as presented above, the method comprising:

• a step of applying at least one vibrating plating member in the horizontal plane to the surface of the ballast bed between said longitudinal rails and between two sleepers so as to reduce the mechanical strength of the upper part of the ballast bed, then
• a vertical dive step of at least one tamping arm vibrating in the depth of the ballast bed between said vibrating plating member and one of said longitudinal rails.

Thus, the application step makes it possible to prepare the ballast bed in order to reduce the mechanical strength of its greater thickness during the vertical dive displacement step. The ballast bed is thus not dull and does not wear prematurely.

Preferably, the method comprises a vertical dive step of at least one tamping arm vibrating in the depth of the ballast bed between said vibrating plating member and each longitudinal rail. Thus, the ballast bed is compacted below the crossbar over its entire length.

PRESENTATION OF FIGURES

• la figure 1 est une représentation schématique de dessus d'une mise en oeuvre d'une machine à bourrer selon l'invention ; et
• la figure 2 est une représentation schématique en coupe d'une forme de réalisation d'un organe de plaquage.

The invention will be better understood on reading the description which will follow, given solely by way of example, and referring to the appended drawings in which:

• the figure 1 is a schematic representation of above of an implementation of a stuffing machine according to the invention; and
• the figure 2 is a schematic sectional representation of an embodiment of a plating member.

It should be noted that the figures disclose the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate.

DESCRIPTION OF ONE OR MORE MODES OF REALIZATION AND IMPLEMENTATION

A stuffing machine according to the invention will now be presented to compact a ballast bed below a cross of a railway track. In a known manner, with reference to the figure 1 , a railway has at least two longitudinal rails 1 extending from upstream to downstream and resting on a plurality of sleepers 2 placed on a ballast bed 3.

The stuffing machine comprises a main frame adapted to circulate on a railway track and comprises, for this purpose, railway wheels. Nevertheless, it goes without saying that the main chassis could be adapted to travel on a road.

The stuffing machine further comprises a plurality of vibrating tamping arms 4 adapted to be immersed vertically in the depth of the ballast bed 3. In this example, each stuffing arm 4 extends vertically and has a frustoconical shape so as to improve the vertical progression in the ballast bed 3. A stuffing arm 4 is a wear element which has to be replaced periodically. Each stuffing arm 4 is preferably metallic. To extend their life, titanium pellets can be added to the stuffing arms 4.

In practice, a stuffing machine has a plurality of stuffing arms 4 to distribute their action on the ballast bed around a cross member 2 whose position must be fixed. Preferably, as will be presented later, the stuffing machine comprises at least one stuffing arm 4 upstream of the cross member 2 and a stuffing arm 4 downstream of the cross member 2.

Each stuffing arm 4 is connected to the frame of the stuffing machine by a displacement and vibration module which allows, on the one hand, to move a determined stuffing arm 4 at a determined location of the ballast bed 3 and, d on the other hand, to vibrate the jamming arm 4 to allow the compacting of grains of the ballast bed 3. It goes without saying that several jamming arms 4 could be connected to the same module of displacement and vibration.

Such stuffing arms 4 are known to those skilled in the art and will not be presented in more detail.

In this embodiment, with reference to the figure 1 the stuffing machine further comprises two vibrating plating members 5 in the horizontal plane adapted to be applied to the surface of the ballast bed 3 so as to facilitate the dipping of said stuffing arms 4 into the depth of said ballast bed 3.

Preferably, each plating member 5 comprises a lower part intended to come into contact with the surface of the ballast bed 3 so as to promote the transmission of vibrations in the upper part of the ballast bed 3 in order to limit the friction between the ballast grains. In other words, the mechanical strength of the upper part of the ballast bed 3 is reduced or "liquefied". Preferably, each plating member 5 is metallic.

Each plating member 5 is connected to the frame of the stuffing machine by a displacement and vibration module which makes it possible, on the one hand, to move a specific plating member 5 to a determined location on the ballast bed 3 and, on the other hand, to vibrate the plating member 5 to liquefy the upper part of the ballast bed 3.

With reference to the figure 1 , each plating member 5 is adapted to be vibrated along a lateral axis, that is to say, parallel to the sleepers 2 of the railway track, in order to transmit vibrations in the dipping areas of the stuffing arms 4 as will be presented later.

According to another aspect of the invention, alternatively or cumulatively, each plating member 5 is adapted to be vibrated along a longitudinal axis, that is to say, parallel to the rails of the railway track, or of circular way.

Each plating member 5 makes it possible to oscillate the upper part of the ballast bed without compacting the ballast deeply in the manner of a compactor. The force applied by the plating member 5 is low.

The lower part of each plating member 5 has a minimum bottom surface of 15 cm ^{2 in} order to transmit sufficient vibrations into said ballast bed 3. Preferably, the longitudinal length of a plating member 5 is less than 60 cm in order to to be able to be placed between two sleepers 2.

Preferably, the plating member 5 comprises an unbalance, that is to say an oscillating mass of reduced mass, adapted to vibrate. The plating member 5 is kept in contact with the ballast bed by a controlled cylinder (the pressure applied being constant) or placed on the ballast bed because of its own weight. In other words, no vertical compaction effort is made.

In another aspect, the plating member 5 has a high mass and is associated with a vibration generator. The plating member 5 is held in contact with the ballast bed by a jack controlled without compacting.

In this example, each plating member 5 has a rectangular shape but it goes without saying that it could be different, in particular, square, round or oval.

More preferably, the lower part of each plating member 5 is full but it goes without saying that it could be partially perforated. According to one aspect of the invention, the lower part of each plating member 5 is in the form of a mesh plate, which makes it possible to trap ballast grains in the openings and thus "integrate" the plating member 5 in the upper part of the ballast bed 3 to improve the transmission of vibrations in the upper part of the ballast bed.

When the lower part of each plating member 5 is solid, it may be flat or comprise an impression with a plurality of reliefs 50, preferably angular as illustrated in FIG. figure 2 , in order to be able to trap ballast grains between reliefs 50 and thus improve the transmission of vibrations.

Preferably, the lower part of each plating member 5, whether it is solid or perforated, is covered with a deformable coating, preferably made of polymer, in order to improve the cooperation between the plating member 5 and the ballast grains by distributing the mechanical stresses in a homogeneous manner. In addition, such a deformable coating makes it possible to limit the wear of the ballast grains, which is advantageous. Preferably, the properties of the deformable coating (thickness, material, and.) Can be adjusted to form a low-pass filter or a high-pass filter to allow only a certain range of vibration frequencies. on the surface of the ballast bed 3. Thus, the vibration frequencies that can cause premature wear of the ballast can be eliminated.

The filling machine also comprises a supply module, thermal, hydraulic, pneumatic or electric, to provide the energy required for the various equipment of the stuffing machine (stuffing arm 4, plating member 5, displacement modules and of vibration).

An example of implementation will now be presented with reference to the figure 1 wherein the ballast bed 3 below a crossbar 2 is to be compacted. For this purpose, an upstream plating member 5 and a downstream plating member 5 are placed between the longitudinal rails 1 of the railway track respectively upstream and downstream of said cross member 2. Preferably, each plating member 5 is placed equidistant from the longitudinal rails 1 to provide sufficient space between the plating member 5 and the longitudinal rails 1.

Then, the plating members 5 are applied against the surface of the ballast bed 3 so that the lower surface of the plating members 5 is in contact with the ballast grains. Each plating member 5 exerts a vertical pressure on the surface of the ballast bed 3. In this embodiment, the plating members 5 are vibrated in the horizontal plane along a lateral axis, that is to say say, parallel to the sleepers 2 to reduce the mechanical strength of the upper part of the ballast bed 3 according to the direction of vibration. The use of relief, a grid member and / or a deformable coating makes it possible to improve the transmission of vibrations in the ballast bed 3 according to the direction of vibration.

Still referring to the figure 1 , upstream stuffing arms 4 (here two in number) are then moved dive into the ballast bed 3 near the cross member 2 between the upstream plating member 5 and each longitudinal rail 1. Similarly, downstream stuffing arm 4 are also moved dive into the ballast bed 3 near the cross member 2 between the downstream plating member 5 and each longitudinal rail 1. In this example, the stuffing arms 4 are also moved dive in the ballast bed 3 outside the longitudinal rails 1 to 2. Thus, tamping arms 4 are located on each side of the cross member 2 along the length of the cross member 2 to compact the ballast bed 3 on which it rests.

During the dive, each stuffing arm 4 is preferably placed in horizontal vibration, more preferably in a rocking movement, to facilitate its insertion into the depth of the ballast bed 3. For example, the frequency vibration is between 35 and 45 Hz.

Thanks to the action of the plating members 5, the tamping arms 4 can enter effortlessly into the depth of the ballast bed 3, which protects the ballast grains and limit their wear. The action of the plating members 5 is even more beneficial that the stuffing arms 4 are located laterally to the plating members 5, that is to say, in the direction of vibration of the plating members 5.

By way of example, satisfactory results for a plating member 5 have been obtained by applying a vertical load of 10KN for a vibration in a horizontal plane in the lateral direction with an amplitude of 1 cm and a frequency of 1 cm. In particular, the number of balls of ballast broken during the dipping of the stuffing arms 4 is reduced by half.

Once in the depth of the ballast bed 3, the stuffing arms 4 can compact the ballast bed through their vibrations. Preferably, the stuffing arms 4 move towards the cross member 2 in order to clamp the ballast bed 3 between the upstream stuffing arms 4 and the downstream stuffing arms 4. By way of example, the clamping force is between 500 and 1000 daN.

Thus, after correcting the geometry of the longitudinal rails 1, this geometry can be fixed quickly and conveniently thanks to the stuffing machine according to the invention without unduly damaging the ballast grains.

Advantageously, thanks to the filling machine, the ballast bed 3 can be successively packed below each crosspiece 2.

Preferably, the plating member 5 is integrated in a tamping-straightener-self-leveling machine. More preferably, the ballast bed 3 can be compacted below several crosspieces 2 simultaneously.

Claims (10)

Stuffing machine for a railway track, the railway track having at least two longitudinal rails (1) extending from upstream to downstream and resting on a plurality of sleepers (2) placed on a ballast bed (3), the machine comprising: at least one vibrating stuffing arm (4) adapted to be immersed vertically in the depth of the ballast bed (3) between said longitudinal rails (1) and said sleepers (2) and - At least one plating member (5) vibrating in a horizontal plane adapted to be applied to the surface of the ballast bed (3), between said longitudinal rails (1) and said crosspieces (2), close to said stuffing arm vibrating (4) to facilitate diving of said vibratory stuffing arm (4) into the depth of said ballast bed (3). Stuffing machine according to claim 1, wherein the machine comprising at least two vibrating tamping arms (4) adapted to be immersed vertically in the depth of the ballast bed (3) between said longitudinal rails (1) and said sleepers ( 2), said vibrating tamping arms (4) being laterally aligned, the plating member (5) is configured to vibrate along said lateral axis. Stuffing machine according to one of claims 1 to 2, wherein the plating member (5) has a flat lower surface plating. Stuffing machine according to one of claims 1 to 2, wherein the plating member (5) has a lower plating surface having a cavity defining a plurality of reliefs (50), preferably angular. Stuffing machine according to one of claims 1 to 2, wherein the plating member (5) has a lower surface of mesh plating. Stuffing machine according to one of claims 1 to 5, wherein the plating member (5) has a lower plating surface covered with a deformable coating. Stuffing machine according to one of claims 1 to 6, comprising: at least two upstream vibrating tamping arms (4) adapted to be immersed in the ballast bed (3) directly upstream of a cross member (2), at least two vibrating tamping downstream arms (4) adapted to be immersed in the ballast bed (3) directly downstream of said crossmember (2), an upstream vibrating plating member (5) adapted to be applied to the surface of the ballast bed (3) between said upstream vibrating tamping arms (4) so as to facilitate the diving of said upstream stuffing arms (4) into the depth of said ballast bed (3), and a downstream vibrating plating member (5) adapted to be applied to the surface of the ballast bed (3) between said downstream vibrating tamping arms (4) so as to facilitate the diving of said downstream stuffing arms (4) into the depth of said ballast bed (3). Stuffing machine according to claim 7, wherein said upstream vibrating tamping arms (4) and said downstream vibrating tamping arms (4) are configured to clamp the ballast bed (3) below the crossbar (2) so as to to compact it. Method for tamping a ballast bed of a railway track by means of a filling machine according to one of claims 1 to 8, the method comprising: - A step of applying at least one plating member (5) vibrating in a horizontal plane to the surface of the ballast bed (3) between said longitudinal rails (1) and between two crosspieces (2) so as to reduce the mechanical strength of the upper part of the ballast bed (3), then - A vertical dive step of at least one vibratory tamping arm (4) in the depth of the ballast bed (3) between said vibrating plating member (4) and one of said longitudinal rails (1). A method of tamping according to claim 9, comprising a step of vertically plunging at least one vibratory tamping arm (4) into the depth of the ballast bed (3) between said vibrating plating member (4) and each rail longitudinal (1).

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