EP1433901A1 - Method and apparatus for laying or exchanging railway rails - Google Patents

Abstract

The process involves electric resistance welding together short rails end-to-end to form long rails onboard a welding train present on a railway track being installed or renewed. The long rails are produced from short rails (7) disposed onboard transport wagons (6) at the rear of the track laying train. The long rails are placed on the track at the front of the train. The rails are measured after being joined together to check for vertical and horizontal alignment of the rails. An Independent claim is included for an installation for implementing the above rail installation process.

Description

The invention relates to a method of laying or renewal of the rails of a railway track, according to which rails are butt welded short long welded rails which will be laid on the track, as well as an installation for the implementation of this process.

We already know a process of this type, which involves the use of a stationary welding installation short rails from 18 to 120 meters, supplied on wagons by a rail rolling mill, in long welded rails of length of 300 meters or more. According to the quality and production requested. This facility is built on a given permanent site and includes all machines that are needed for welding rails, such as a brushing machine for the ends of the rails to be welded, a welder, a press, a finishing grinder, alignment measurement systems, tables supply and discharge and conveyors for the transport of rails from their production site to construction site.

This process has the major drawbacks of require a very high investment cost and require transport of long welded rails from the site of their production at the site where they are to be installed and the length of which is therefore limited. In addition, the rail laying or renewal process is long and involves a lot of unproductive time related to transport of rails from their production site to construction site.

Another known method involves unloading short rails from 18 meters to 120 meters on along the way to establish or renew and welding short rails lie on the ground in long rails welded on site, the length of which can be theoretically infinite. The installation used at this fin is composed of a mobile electric welder, mounted on road-rail, railcar or in installed containers on flat cars.

This process has the major drawback that the quality of the route obtained leaves something to be desired although investment, especially for the electric welder mobile is relatively high.

The object of the invention is to propose a method and an installation which overcomes the disadvantages of state-of-the-art processes while retaining the benefits they provide.

To achieve this goal, the method according to the invention is characterized in that the long rails are produced welded on a welding train, on site, from short rails arranged on transport wagons at rear end of train, long welded rails being placed on the track at the front end of the train.

The installation according to the invention for setting up work of this process is characterized in that it is produced in the form of a welding train comprising wagons carrying the machines necessary for the production of long welded rails, such as a end brush of the rails to be welded, of a welder, a press, a finishing grinder, conveyors for transporting rails from one wagon to another from wagons on which the short rails are loaded.

La figure 1 représente un train de soudage en cinq tronçons a-a' à e-e' successifs qui sont superposés sur la figure ;

La figure 2 est une vue de face d'un poste de soudure ;

La figure 3 est une vue latérale du poste de soudure de la figure 2;

La figure 4 est une vue de dessus du poste de soudure des figures 2 et 3 ;

La figure 5 est une vue en coupe d'un rail ;

La figure 6 est une vue de face d'une presse pour l'opération de redressage ;

La figure 7 est une vue de dessus de la presse de la figure 6.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly during the explanatory description which follows, made with reference to the figures illustrating the invention by way of non-limiting example. .

Figure 1 shows a welding train in five sections aa 'to ee' which are superimposed on the figure;

Figure 2 is a front view of a welding station;

Figure 3 is a side view of the welding station of Figure 2;

Figure 4 is a top view of the welding station of Figures 2 and 3;

Figure 5 is a sectional view of a rail;

Figure 6 is a front view of a press for the straightening operation;

Figure 7 is a top view of the press of Figure 6.

As shown in Figure 1 at the top left, the welding train has at the front end a locomotive 1 and, if applicable, a second locomotive not shown at the rear end and between the two locomotives, coupled to each other, wagons workshops, which carry the different machines necessary for the production of long welded rails, wagons carrying auxiliary equipment indicated for example in 4, transfer wagons 5 of rails from one workstation to another and railcars transport of short rails as indicated in 6, on which the short rails are placed in several layers, these cars being located at the rear end of the train which is a free end.

The welding train, the length of which depends on short rails to weld, is formed to have the shape represented and then be directed to the site. The set is towed by locomotive 1 to the place where the long welded rails are to be laid. Once arrived on site, the securing of the layer top of short rails on transport wagon 6 is dismantled and a first rail 7 is removed from wagon 6 by a winch mounted on the adjacent wagon 8 and indicated by 9. At 10 we indicate the traction cable which is fixed to rail 7, some distance from the end of this one. The short rail 7 is pulled so that it engages in a pressure roller device 11 also carried by wagon 8. During its transfer from wagon 6 with the pressure rollers 11, the rail 7 moves on a upward ramp 12.

It should be noted that the first rail 6 was at the middle of the top layer on wagon 6. The second rail, successive to the first rail 7 is connected to the first rail by self-tightening clamps.

The pressure roller 11 advances the rail 7 up to wagon 13 which carries an automatic brushing machine ends of rail 14. Once the upstream ends and downstream detected and positioned in this brushing machine, the automatic cycle of the machine, which works without operator, triggers and the work schedule, the underside of the rail pad and the cut of both ends rails are deoxidized. The train remains in its position initial during this operation and operations following.

The two rails advance on the central conveyor until the upstream end of the second rail is located in the axis of the brushing machine. On the one hand the operator of the winch loads the following two rails on the conveyor and the downstream end of the first rail is positioned in the brushing machine which automatically starts a new cycle brushing.

On the other hand, the operator of the welder-deburring machine which performs electrical welding such as welding by spark, move the machine on its way in the wagon closed, until the ends of the first and second rail are in the axis of the machine, ready to be welded. Machine cycle aligns automatically the two ends of the rails, weld the rails following a programming of established parameters according to the type of rail and tested, to finally deburr the welding.

In the example shown in the figures, the welder-deburring machine is supplied with electrical energy, like all the machines equipping this train, by the wagon power supply. The test welds are tested in the test press, installed in a wagon workshop-store.

Advantageously, positions such as that of the welder-deburring machine or any other station are supplied by different power supply groups autonomous, so that the train is modular, in according to the technical requirements of the site on which it intervenes.

After welding, the welded rails are cooled during their advancement, by means of rollers suitable pressers up to wagon 20 carrying a press in four directions 21, the train still being immobilized. The cooling of the weld could do in a water tunnel mounted in a closed wagon. In depending on the productivity, we will determine if the tunnel installed at one or two lengths standard of short rails of the deburring machine. The solder temperature is measured on the fly, by a pyrometer, installed along the conveyor, up to the water tunnel.

Depending on the temperature measured, the cooling is initiated or a waiting time is established. Cooling the weld to temperature room is necessary to be able to perform the finishing operations and check the alignment of the two short rails at the weld. The four-man press directions 21 is equipped with a laser measurement system, able to control alignments in vertical planes and horizontal over lengths up to three meters. The press is movable inside wagon 20 and the operator positions the machine until the solder is in the axis thereof. A first measurement cycle is performed and the result in the form of two graphics is shown on a monitor. In depending on this result, the operator performs the vertical and horizontal straightening operations necessary to obtain an alignment corresponding to the tolerances required. After the straightening cycle, a new measurement cycle is carried out. If the solder remains out of tolerance, a new recovery cycle is made.

After the measurement and straightening, the rail with the weld is transported on the central conveyor to the closed wagon which contains the automatic finishing grinder 24 welds and a laser measurement system, coupled with the grinder and able to control alignments in vertical planes and horizontal over lengths up to 3 meters. The machine is mobile and the operator positions the machine until the weld is in the axis of it. After performing the grinding cycle, the operator moves the machine until the solder is in the axis of the measuring system and performs a measuring cycle of the required length. In exceptional cases where the results are not inconclusive, a correction by grinding can be performed.

After grinding and final inspection, each solder has undergone all the finishing operations and is moved on the central conveyor until the end of the long welded rail touches the ground at the place provided when positioning the welding train on the way. The rail is moved in a laying chute 27 providing vertical and horizontal guidance.

The long welded rail obtained by welding the rails short 7 from wagon 6 can be positioned in the lane or off the lane.

During all phases of production, described so far, the welded rail is moved by pressure rollers while the welding train remained immobilized on the track.

Once the long welded rail hits the ground and is connected to the route to be renewed or to the provisional route, by means of self-tightening pliers, the welded rail is kept stationary and the welding train is moves. The operations carried out in the wagons of train remain the same as before.

The use of self-tightening pliers which is generally necessary at the start of intervention on a track is not essential in the subsequent installation of a long rail.

Indeed, the self-weight of a rail on a length of one hundred or two hundred meters is usually sufficient in itself to ensure the stable maintenance of this rail along the track during the movement of the train.

During installation, the movement of the rail along the train while this train is moved can possibly be assisted by the pressure rollers having a movement synchronized with the movement of the train.

During all operation, the train has a substantially sequential movement, in which it advances at low speed a rail length and then stops to weld the short rail next.

In the example of the figures, locomotive 1 is mainly intended to transport the train to the site where he intervenes. This train is advantageously planned self-propelled, slow running, to allow sound moving at low speed and immobilizing it with satisfactory positioning accuracy, without intervention of locomotive 1 when it is on site.

The implementation of a self-propelled train planned for movements at low speed, in association with longitudinally mobile stations, such as for example the welder-deburring station allows for a sequential advancement with a relatively high rate. Indeed, the positioning of the self-propelled train presents important precision when it stops, and each station which is movable longitudinally relative to the wagon carrying it can quickly be positioned by relation to the rail on which it must intervene, without it either need to readjust the position of the entire train.

Note that the pressure rollers motorized, mounted downstream of the welder-deburring machine reprogrammed by triggering the drive rollers and decreasing the pressure on the pressure roller so that change the function in a guidance function and braking of the welded rail taking account of superelevation and line gradients. Advantageously, these systems of guide and displacement of the rails include a roller base rotating around a horizontal axis, on which rolls the rail, two side rollers surrounding the rail and rotating around vertical axes, and a pressure roller, located at the top of the rail and the pressure it can exert can be controlled.

After the description which has just been made, we notes that the welding process proposed by the invention and its implementation train have many advantages over the state of the art. The invention has the advantage of requiring a qualified production and maintenance personnel reduced. Taking into account the means implemented such as advanced automation, a control system quality, full traceability that the invention provides, the establishment of a reduced team of qualified personnel is justified and profitable, which is not not the case for welding processes according to the state of technique, for which the teams are heterogeneous depending on the places of work. The traceability of each weld is possible, both for the parameters metallurgical, at the welder-deburring station, that for geometric parameters, at level of straightener and grinder. The invention allows a very high production, on the one hand ensured by the means implemented and secondly by continuity and qualification of personnel. The work is done in closed places, i.e. in closed wagons and heated, regardless of weather conditions. The invention provides better metallurgical quality welds, guaranteed by means of adjustment and control of the different welding parameters and the hydraulic power of the machine, ensuring forging optimal welds. The invention also guarantees a geometry and perfect alignment of the welds on long distances, with alignment tolerances the more stringent for high-speed lines, thanks to the presence of a four-way hydraulic press with integrated laser measurement system, capable of monitoring the alignment of the welds in two planes on distances up to three meters in length and a automatic grinder perfectly copying and connecting the profile of the two rails welded over a distance of up to one metre.

A major advantage offered by the invention lies in the possibility of welding rails lengthwise infinite, removing the need to connect long rails welded by thermite welds in the way. The production line is supplied with from wagons carrying short rails between the supplier's rolling mill and site, without unloading short rails before welding the track. he there is no prior installation of the rails to be welded on the foundations of the railway sleepers to ensure minimal alignment of the ends of the rails before welding.

The invention makes it possible to adapt the position of the machines at standard length of short rails, capable of vary between 18 meters and 120 meters or more, changing the length or position of the cars dividers to ensure the operation of all the machines of the line in masked time. Machines are placed on tracks, fixed on the wagon floors, allowing their positioning exact towards the welds to be treated. The invention guarantees complete autonomy of the welding train to the point of view of electrical, hydraulic and pneumatic. The invention provides a repair shop and a stock of spare parts. The invention provides a complete autonomy of the welding train, which can be move on all networks meeting the template and track gauge. It is possible to transport the welding train to other continents in the "standardized containers" version.

According to the invention, the welder used which is visible in Figures 2 to 4 is intended to achieve flash welds. It has two parts 25, 26 one being movable longitudinally relative to the other thanks to two jacks 27 connecting these two parts, these cylinders being powered by a hydraulic system of strong power. This welder is also globally longitudinally movable on rails 28 equipping the wagon carrying it. Each part 25, 26 of this welder includes means for positioning and fixing the rail it receives. One of these two parts can be moved precisely vertically and transversely with respect to each other, so that adjust the alignment of the two rails to be welded, this relative movement is for example made possible by a eccentric system.

Flash welding is performed by application of an electric current crossing the rails, then by rapid approximation of the two rail ends under high pressure, this electric current being generated by a transformer identified by 29.

When the rails are put in position, i.e. aligned with each other, and separated by a small air gap, the welding cycle can start. This cycle possibly includes several preliminary steps planned to preheat the ends of rails to be welded. The welding cycle per se involves applying an electric current through the air gap, which raises the temperature but generates loss of material by projections. This loss of matter is compensated by a slow advance of a part of the machine compared to the other.

This slow advance takes place on a race that can reach twenty to twenty-five millimeters for the whole a welding cycle, and it is controlled by the intensity of the electric current flowing through actually the rails. If this intensity reaches a value too high, the feed speed is reduced, even reversed, and if this intensity becomes too low this advance is increased.

This slow advance which takes place at the start of the welding is advantageously managed by a PLC controlling the hydraulic system which is associated with the welder and the cylinders 27, depending on the intensity of the current.

This electric current produces a fusion of ends of the rails which thus reach a temperature satisfactory in about two minutes. When this temperature is reached, the machine is controlled so that its hydraulic system brings the two halves by applying an effort of the order of sixty tonnes, which produces forging welding having high mechanical strength.

The rail positioning members in this welder, include references to ensure placement in geometric conformity of the rails, as well as the jaws or other clamping devices provided for holding of these rails, in each part 25, 26.

Advantageously, the reference point is achieved on the one hand at the level of the rolling face 30 of the rail, that is to say the upper face intended to receive the wheels of a train, and on the other side active 31, i.e. the face against which the flank of a train wheel is likely to take support, this which is shown diagrammatically in FIG. 5.

This particular provision for setting compliance cancels the effect of dispersions of dimensions of the section of the rails to be welded on their alignment. Despite a significant difference in section dimensions of two rails to be welded, the strip bearing 30 and the active face 31 of the rail which are its two functional parts are so in the extension of one another.

Advantageously, the two rails are welded with a slight angle, having a predetermined value, in the plane vertical. The welded rail points slightly upwards at the weld level, to be replaced substantially horizontal after the straightening operation. Considering of a so-called weld memory effect in the life of the rail, this tends to form a slight angle, which counteracts the effect of passing trains which tends to press the rail towards the ground at the weld.

After welding, the angle formed by the two rails can be worth for example five to six tenths of millimeters, over a distance of one meter extending from on either side of the weld. This angle is reduced to a much lower value after the operations of welding and grinding.

According to the invention, when the train advances for lay the rail, the movement of the rail relative to the train is assisted by pinch rollers which are arranged in particular on either side of the welding. This helps reduce efforts longitudinal applied to the weld which has just been made to avoid degrading its mechanical qualities.

The use of these pressure rollers which move rail relative to train contributes also to reduce the tractive effort which must be developed for moving the train relative to ground.

According to the invention, after completion of the weld, the alignment of the welded rails is measured to be possibly rectified in a post 21 including measuring devices and a press, shown more detailed in Figures 6 and 7.

This station 21 is also movable longitudinally on rails 32 fitted to the wagon carrying it for ability to adjust its longitudinal position relative to the welding.

It includes a reference rule 33 which extends horizontally parallel to the longitudinal axis of rails over a length worth for example three meters, and along which a measuring head 34 moves to determine the misalignment of the two rails on the one hand in a horizontal plane, and on the other hand in a vertical plane. This head 34 is equipped with means for laser measurement allowing measurements of a level of highest possible accuracy.

As shown in Figures 6 and 7, this rule 33 is mounted inside station 21 which includes mainly a four-axis press capable of straighten the rail in the vertical plane and in the plane horizontal, in both directions.

This station includes two ablots A1, A2, which are supports supporting the rail on either side of the welding. These two supports each have an open C shape upward, so that they can exercise a reaction on the rail transversely in both horizontal directions and in a vertical direction.

This station includes in its central part a jack double-acting 35, arranged horizontally to operate a hammer. It also includes two vertical cylinders and 36 and 37 are arranged vertically to actuate a hammer either from top to bottom, or from bottom to top.

This four-axis press is powered by a hydraulic unit not shown, so that develop efforts of up to one hundred and twenty tonnes in the horizontal plane, and two hundred and fifty tonnes in the vertical direction. It is driven by a machine or by an operator so that the cylinders operate the hammer to apply welding forces whose intensity depends on the misalignment which is measured at head level 34. The system of measure being integrated in the press in station 21, it is thus possible, if necessary to carry out several straightening passes by performing a measurement between each pass, so as to achieve a very precise alignment of the two rails.

This press still includes two ablots additional, not shown, intended to be placed in the upper part of the rail on either side of the welding, and intended to be used when the cylinder lower vertical is activated.

The train grinding station according to the invention also includes a precision measurement system, to further improve the alignment of the two rails by grinding, possibly in several passes. This system measurement allows a final measurement of alignment, corresponding for example to a control of quality before installing the rail on the track.

This straightening operation as well as the operation of grinding make it possible to carry out welds of rails for high speed lines, in which the possible tolerances are much more demanding than for classic lines. For example, the alignment tolerance for a conventional line is two tenths over a distance of one meter, while the tolerance for a high speed line is two tenths over a distance of three meters.

Claims (15)

Method for laying or renewing the rails of a railway track, according to which short welded rails are produced by butt welding of long rails which are laid on the track, in which long rails welded on a welding train, on site, from short rails (7) deposited on transport wagons (6) at the rear end of the train, the long welded rails being placed on the track at the front end of the train, characterized in that one carries out, after welding a measurement operation of the alignment of the welded rails and that one performs according to the measurement result, if necessary, straightening operations. Method according to claim 1, characterized in that the different rail treatment stations are placed in the welding train successively and the short rails (7) pass through the different stations by moving them from the transport wagon (6) at the front end of the train installation. Method according to claim 2, characterized in that the short rails (7) are gripped on the transport wagon (6) one after the other, aligns the rails and moves them in the aligned state at the station. aforementioned treatment. Method according to claim 3, characterized in that the short rails (7) are moved after gripping the adjacent ends of the short rails to obtain a rail on the transport wagon (6) at an electric welding station (17) long, after performing a brushing operation on the ends to be welded. Method according to claim (4), characterized in that the measurement operation of the alignment of the welded rails is carried out in the vertical and horizontal planes, and in that the straightening operations are also carried out in the vertical and horizontal planes , after having subjected the long rail obtained to cooling. Method according to one of claims 2 to 5, characterized in that the front end of the long rail is placed on the ground by guiding it using a laying chute, vertically and horizontally. Method according to one of Claims 1 to 6, characterized in that before the front end of the long rail is laid on the ground, the welding train is kept stationary and the rail for formation is moved. Method according to one of Claims 1 to 7, characterized in that after the front end of the long rail has been laid on the ground, the rail is kept stationary and the welding train is moved. Installation for implementing the method according to claim 1, characterized in that it is produced in the form of a welding train comprising wagons carrying the machines necessary for the production of long welded rails, such as a brushing machine ( 14) of the ends of the rails to be welded, a welder (17), a straightening press, a finishing grinder (24), conveyors for transporting the rails from one wagon to another from the wagons (6) on which the short rails (7) are loaded. Installation according to claim 9, in which at least one of the machines is mobile longitudinally with respect to the wagon carrying it. Installation according to claim 10, in which the train is of the self-propelled slow running type. Installation according to one of claims 9 to 11, in which the different machines are electrically powered by different groups autonomous power supplies. Installation according to one of claims 9 to 12, characterized in that the brushing machine is an automatic machine. Installation according to one of claims 9 or 12, characterized in that the welder is movable on its carrier wagon and adapted to weld the rails according to a programming of the preset parameters. Installation according to one of claims 9 to 14, characterized in that it comprises a closed wagon carrying a water tunnel for cooling the welds after welding.

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