EP0467833B1 - Method for the neutralising of railway rails in-situ - Google Patents

Abstract

The new rails (R2) to be laid are continuously heated so they can be neutralised. To this end, they are lifted up and exposed to a heat source in the form of two heating tunnels (15) which are mounted on a vehicle (1) which moves continuously along the old rails (R1). Each heating tunnel (15) has passed through it a length of new rail (R2). At the same time, the old rails (R1) are detached from the sleepers and, after the passage of the said vehicle (1), are deposited alongside the track, or are removed. The new rails, which are brought to and maintained at the neutralisation temperature, are laid continuously onto the sleepers so as to be fastened thereto. <IMAGE>

Description

The invention relates to a process for neutralization before rail track fixing, in which at least one heating element is continuously scrolled along the new rails and the heating is controlled or controlled so that the temperature new rails at the fixing area correspond to the desired temperature.

Such a process is known from US Pat. No. 3,896,734, according to which an installation for laying railway rails comprises means for heating the new rails before they are fixed to the track. These heating means are provided to ensure a temperature approximately equal to the average of the annual site temperatures.

The present invention proposes to create an improved heating method compared to the known method of said American patent, in the sense that it makes it possible to obtain the desired temperature in a more efficient and easy to execute manner.

To this end, the method according to the invention is defined by the characteristics of claim 1.

The heating of the rails is preferably carried out by high frequency induction, but it can also be carried out by electrical resistance or by gas.

The invention will be described using two embodiments of the device for implementing the high frequency heating method, with reference to the accompanying drawings.

Figure 1 shows a schematic view of a heating vehicle fitted with two high-temperature heating tunnels frequency allowing the implementation of the method according to the invention.

Figure 2 is an enlarged sectional view of the tunnels alone.

Figure 3 is the control block diagram of an installation for high frequency induction heating according to the invention.

Figures 4 and 5 show a second embodiment of a heating vehicle followed by an assembly vehicle for fixing the new neutralized rails.

FIGS. 4a and 5a are top views of the track to illustrate the positions of the old rails R1 and of the new rails R2 and their lateral displacement during substitution, as well as some components of the vehicles.

FIG. 6 is an enlarged sectional view of the tunnels alone according to FIG. 4.

Figure 7 shows in section, like Figure 6, a variant of the tunnel arrangement.

FIG. 8 is the control block diagram of a heating installation adapted to the device according to FIGS. 4 and 5.

Referring to Figures 1 and 2, we first briefly describe the example of a vehicle 1 on which is installed the heating device incorporated in the heating tunnels 5, 5 '. Vehicle 1 is designed to roll on the old track R1, in the direction of the arrow, to lift the new rails R2 previously deposited along the track and neutralize them by heating immediately before their installation and, simultaneously, to detach the old rails R1 from the way.

The vehicle 1 comprises a body 2 supported by a front bogie 3 with two axles 3a and by a rear bogie 4 also with two axles 4a. Between these axles 3a, 4a are installed the two heating tunnels 5, 5 ', one for each row of new rails R2 (Figure 2).

As illustrated in FIG. 2, these two tunnels 5, 5 ′ are mounted in common frames 6 arranged above the center of the track and suspended below the body 2. They are formed by two side walls 6a separated by a common central wall 6b. The three walls of the frame meet at their upper part and, at determined intervals, are extended by uprights 6c suspended from the body 2, such that the location of the tunnels is centered relative to the body 2 and therefore relative to the way. The rails to be neutralized R2 are heated by high frequency induction; for this purpose, the rails R2 pass inside inductors in the form of coils 12 to a turn connected to inverters, and move on guide rollers 7 fixed in the walls 6a, 6b of the tunnels 5, 5 'between the inductors.

The arrangement of these tunnels 5, 5 ′ is such that the trajectory of the rails R2 to be neutralized is located below the axles 3a, 4a, at a distance from the ballast of between 20 to 40 cm, preferably between 25 and 30 cm. Thanks to this arrangement, it is necessary to avoid having to lift the rails very high and above all above the axles, which facilitates the work and the guiding of the rails.

On either side of the tunnels 5, 5 ′ are provided work stations in retractable nacelles 9, 10 suspended from the vehicle body 2 by jacks 9a, 10a and on which there are automatic or manual stain removal stations , for example automatic screwdrivers 9b, 10b and rolling seats 9c, 10c for workers who remove the fasteners or release the fastenings of the old rails to the sleepers.

At the head of the vehicle 1 are installed gripping means 8 of the new rails R2 previously disposed in the center of the track or on either side of the track. These gripping means a make it possible to grasp and introduce these rails R2 into the opening before the heating tunnels 5, 5 ′.

At the rear of the vehicle 1 are provided rail clamps 11 which grip the new heated rails R2 at the exit of the tunnels 5, 5 'and guide them on the track where, after the old rails R1 have been removed, they will be laid and then fixed on the sleepers by known means.

Referring to Figure 3, we will now describe the block diagram of the installation for the implementation of the neutralization process on the railroad tracks, by high frequency induction.

This heating installation, mounted on the heating vehicle 1, comprises a heating zone formed by several inductors distributed in each tunnel 5, 5 '. In the example considered there are three inductors 12, 13, 14, arranged one after the other, which are formed, in a manner known per se, by a coil with a coil made of hollow copper tube, with a length of 1m each. These are inductor modules of similar construction, prefabricated, which makes it possible to compose heating zones of desired length by varying the number of these modules as required.

By using only three inductors with a length of 3 m, it is obvious that the tunnels 5, 5 'can be shorter than indicated in Figure 1.

The inductors 12, 13, 14 are supplied by two inverters 15, 16 with a power of 100 KW respectively 200 KW and 1000 Hz. The inductor 12 is connected to the inverter 15 of 100 KW and the inductors 13, 14 are connected to the 200 KW inverter 16, which allows flexibility in temperature regulation. There is also provided a refrigeration unit, not illustrated, to ensure the cooling of the inductors by circulation of cold water through the hollow turns, in a closed circuit, without continuous supply of water from outside the convoy.

Of course, a heating installation is provided with three inductor modules in each of the tunnels 5, 5 ′ illustrated in FIGS. 1 and 2, and crossed as described previously by each row of new rails R2.

The inverters 15, 16 are connected to an electronic control unit 17. In front of the inductors 12, 13, 14 are installed in each tunnel 5, 5 'of the devices 18 for measuring the running speed of the rails R2 relative to the vehicle 1 and sensors 19 for measuring the temperature of the rails before their exposure to heating. In FIG. 3, the distance ZF of the new rails R2 has been indicated at a distance L from the end of the heating zone, therefore from the rear end of the inductor 14. Over this distance L are installed, at regular intervals, several sensors 20 for measuring the temperature of the rails which capture the slow cooling of the rail which occurs. In general, the rear end of the last inductor 14 coincides with the rear end of the tunnel 5, 5 '.

The electronic control unit 17 to which the outputs of the units 18, 19, 20 are connected, therefore receives all the information on the speed and temperature conditions of the rails R2. In addition, this unit 17 also receives external information by an input unit 21 and set values by an input unit 22 via an operator control interface 23 adapted to personnel. exploitation. The external information includes all the essential external factors, namely the profile of the rails, the type of steel from which the rails are made, the outside temperature and, if applicable, other factors which could influence the cooling speed of the rails (rain, wind, etc.)

To this unit 17 are also connected, as output units, a device for printing protocols 24 and an optical unit 25 for viewing the temperature profile and the state of the process.

The electronic control unit 17 includes the processing of temperature measurements, the regulation of the heating stations, the management and the control of the process as a function of the values of the temperature of the rails before their exposure to heating, of the speed of travel of the heating elements with respect to the rails, from the value of the change in temperature of the rails after heating up to the time of their attachment to the track.

To achieve uniform heating of the mass of the rails throughout their section, it is necessary, after heating, to wait a certain time for the temperature during the cooling phase to equalize in the mass of the rail. For this reason, the distance L is important and will be chosen in such a way that, for a given speed of travel of the heating elements, the temperature difference between the surface and the core of the new rails does not exceed a determined value and that the temperature of the new rails at the ZF fixing zone corresponds, with given tolerances, to the desired temperature.

In general, the neutralization temperature during fixation should be 25 ° C ± 0.5 ° C. In regards to equalization of the temperature, it was found that, for example for a running speed of 6 m per minute, and for lengths respectively of L = 8m, L = 10.5m, L = 17m and L = 21m, the temperature difference between the surface and the core of the rail, expressed as a percentage difference, amounts respectively to 8, 6, 4 and 3%. So if we choose an absolute difference in surface / core temperature difference of 4% of 25 ° C, therefore ± 1 ° C, we must choose a length L = 17m, which corresponds to a running speed of 6 m / min at a time of 170 s. Therefore, the distance L depends mainly on the permissible temperature difference between the surface and the core and the speed of movement.

Figures 4 and 5 show, as a preferred example, a second embodiment of a heating vehicle 1 having shorter heating tunnels 5a, 5b, followed by a mounting vehicle 2 of the new rails.

The parts of the heating vehicle 1 which correspond to the parts of the first example have the same reference signs. In this case, the heating tunnels are shorter.

The vehicle 1 (FIG. 4) fitted with a front bogie 3 and a rear bogie 4 rolls on the old rails R1 and comprises a box 2 comprising a cabin 2a, compartments 2b for inverters which supply the inductors of each tunnel high frequency heating, compartments 2c for the refrigeration units which cool the inductors, a tank 2d for the fuel oil, generator groups 2e which supply the inverters, as well as groups of capacitors 2f assigned to the inductors. The new R2 rails, previously deposited in the middle of the track, are gripped at the head of the vehicle 1 by gripping means 8 and placed on the guide rollers 28 fixed to the chassis of the vehicle and distributed along the latter so that the new rails R2 can pass under the axles 3a, 4a and between the wheels of the bogies 3 and 4.

The heating tunnels are installed in the area of the rear end of the vehicle 1 in the middle of the track. In the case under consideration they are divided into two parts 5a, 5b fixed to the frame 29, one located before and the other after the rear bogie 4. Part 5a comprises two inductor units each having a length of 1 m, and therefore is only 2 m long, while part 5b only has one inductor which is 1 m long. Each inductor 12 has the form of a coil with a turn and is connected to a group of capacitors, the oscillating circuit formed by this coil and these capacitors being supplied by inverters. Due to the short length of the tunnel, the R2 rails do not need to be guided inside the tunnel, but can pass it freely. Of course, each part of the tunnel comprises two sections placed side by side, one for each row of rails, as shown in FIG. 6 for the parts 5a, 5a ', provided with inductors 12 surrounding the two rails R2. In order to ensure good centered guidance, each part of the tunnels can be provided with rollers 7a which rest and roll on the rails R2 passing this part, these rollers being installed before and after the inductors, respectively between the inductors. The parts of the tunnels are suspended from the chassis 29 so that they are somewhat mobile relative to the chassis to allow them to adjust themselves.

According to the variant of Figure 7, the two sections 5a, 5a 'of the tunnel provided for each rail file are slightly spaced from each other, connected by a cross member 27 and suspended from the frame 29 by jacks 29a which allow them to be lifted when walking high. Each tunnel is provided not only with rollers 7a which rest on the rails R2, but also on either side of each rail, rollers 7b providing lateral guidance.

To detach the old rails R1, spotting stations are provided on two nacelles 9, 10 suspended from a frame 29; these nacelles are equipped with tools for removing fasteners such as automatic spanners 9b, 10b and are fitted with wheels 9d, 10d to roll on the rails R1.

At the rear, the vehicle 1 has rail guides 33 for the old released rails R1, a cantilever frame 30 carrying an adjustable support 31 provided with rail clamps 31a which lift the rails R1 (Figure 4) and move them apart (Figure 4a), as well as a track 32 rolling on the sleepers to prevent them from coming out of the ballast when lifting the rails R1. The frame 30 can be moved towards the interior of the vehicle thanks to the rollers 30a rolling on slides of the frame 29.

The mounting vehicle 40 (Figure 5) having the bogies 35 and 36 rolls on the new rails R2 which are placed in their correct position on the crosspieces at the front of the bogie 35. For this, the vehicle has at the head a frame 37 cantilevered with an adjustable support 38 carrying rail clamps 39 to spread the rails R2 towards the fixing positions, as shown in the Figure 5a. The frame 37 can be moved towards the interior of the vehicle by means of the rollers 37a rolling on slides of the chassis 40a.

Below the chassis 40a of the vehicle 40 are mounted an auxiliary heating tunnel 5c, positioned at the head of the said vehicle and covering the rails R2 from above, as well as other rail clamps 39a for positioning these rails R2 on the sleepers T. This auxiliary tunnel 5c only comes into operation in the event of work being interrupted, to warm up the R2 rails already out of the tunnel 5a, 5b before they are fixed.

A connection 41 between vehicles 1 and 40 comprising an electric line and a cooling pipe is used to supply this part 5c of the tunnel.

The vehicle 40 further comprises front 42 and rear 43 cabins, a generator group 44, as well as mounting stations on the two nacelles 45. These nacelles are suspended from the chassis 40a and provided with tools for mounting the fasteners, in particular automatic spanners 46, as well as wheels 45a for running on the rails R2. The old rails R1 are guided by guide rollers 47 and deposited next to the track as shown in Figure 5a.

At the tail of the vehicle 40 are provided means 48 for picking up the fasteners removed by the stain removal stations of the vehicle 1 and deposited on the track. These fasteners are transported by conveyors 48a to storage places 49 and by conveyors 50 to the attachment stations on the nacelles 45.

Figure 8 shows the installation block diagram intended for vehicles 1 and 40 according to Figures 4 and 5 and is very similar to that illustrated in Figure 3. The same units are identified by the same reference signs and will not be re-described. The modifications compared to Figure 3 are as follows:

An inverter 15a, pe of 50 kW, supplies the two inductors 12, 13 mounted in each part 5a of the tunnels, and an inverter 16a, pe of 100 kW, supplies the inductor 14 mounted in each part 5b of the tunnels or else an inductor auxiliary 26 mounted in each part 5c of the tunnels at the head of the vehicle 40. An inverter 27 makes it possible to connect the inverter 16a to the inductor 14 or 26. The inverters in this case work at 2 kHz. Each inductor, designed as a module, is formed by a coil with a hollow coil and its length is 1 m.

Of course, the method according to the invention could be implemented by installations other than those which have just been described, in particular the heat source could be different. The high frequency induction heating which is the preferred heating could in particular be replaced by an electric resistance heating or by a gas heating.

Claims (4)

1. Process for on-track neutralisation of the rails of a railway before their fixing according to which at least one heating element is caused to move past continuously along the new rails and- the heating is controlled or slaved such that the temperature of the new rails in the zone of fixing corresponds to the desired temperature, characterised in that

   - the value of the temperature of the rails before their exposure to the heating is measured continuously,

   - the value of the speed of movement past of the heating elements in relation to the said rails is measured,

   - several successive values of the temperature of said rails are measured for a distance (L) between the finish of the heating zone and the place where the neutralised new rails are fixed on the track, said several values of the temperature representing the evolution of the temperature of said rails, and

   - the heating of the heating elements as a function of the said values is controlled or slaved,

   said distance (L) is chosen, for a given speed of movement past of the heating elements, in such a manner that the difference in temperature between the surface and the core of the new rails does not exceed a specified value in the place where the neutralised new rails are fixed on the track and that the temperature of the new rails in the zone of fixing corresponds, within given tolerances of said difference in temperature between the surface and the core, to the desired temperature.
2. Process according to Claim 1, characterised in that the heating is carried out by high-frequency induction.
3. Process according to Claim 1, characterised in that the heating is carried out by electrical resistance.
4. Process according to Claim 1, characterised in that the heating is carried out by gas.

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