EP0329918B1 - Method for the restoration of a railroad track - Google Patents

Abstract

In order to define an absolute basis of reference, during the restoration of a railroad track, a system of electromagnetic wave transmitters (E1) is placed near a predetermined fixed point, at a maximum distance (A2 A'2) beside the track (V) determined by the free space available compatible with the lateral travel of the receiver system (Rr). The vertical and lateral deviations of the transmitter (E1) with respect to the theoretical axis of the track are measured and entered into a computing system for determining the corrections to be carried out. In the curves the transmitter system (E1) is disposed outside of the chord (N1 M1) on the secant prolonging it and therefore outside of the curve (A'1 A'2) in order to elongate the length of the measuring and working interval (P3) which is thus longer than if the system of transmitters were placed on the track. Preferably two transmitter systems are used placed on the outside of the track allowing the transport of the system of transmitters not in service during the work interval without disturbing the operation of the system of transmitters in service. In this way the stop time of the machine is greatly reduced. <IMAGE>

Description

The invention relates to a method according to the preamble of claim 1.

Such a process is known from EP-A-0213253. The transmitter, formed by a laser transmitter, is installed on a carriage which rolls on the track and which, during the measurement operation in an interval, is parked on the track in front of the machine near a fixed reference point . Thanks to a special optical system, the laser beam is divided into a vertical plane serving as a reference base for shifting, and a horizontal plane serving as a reference base for leveling. The receivers automatically adjust to the vertical and respectively horizontal beam.

In addition, a machine in the form of a tamper-grader-ripeuse by means of which this method can be implemented, is known from EP-B-0090098 and EP-A-0207197, both being deposited by the plaintiff. The transmitter which is also parked on the track is preferably made up of a laser transmitter designed so that its beam can be rotated on its axis to emit a fan or scanning beam in a vertical plane and a horizontal beam. This machine advances step by step, from cross to cross, and at each stop or cross we proceed to leveling then, after having turned the laser transmitter by 90 °, to shifting. The machine can also work continuously with stuffing tools.

In curves, the rope of a section of track which is, in the known machine, formed by a laser beam in a fan or with scanning in a vertical plane, is used as absolute reference line. This cord usually extends between the transmitter which is on the director rail or the axis of the track and the point of intersection of the beam with the director rail or the axis of the track. The position of the reference line, as defined above, is called absolute because the successive positions of the transmitter are determined with respect to points fixed points which were defined during the first track layout and the correct position of the track is determined according to these fixed points. These fixed points are materialized either by topographical markers, or by points located on pylons arranged next to the track. By placing the transmitter on the theoretical axis of the track or the theoretical position of the director rail and by entering its coordinates relative to the fixed point, a calculation system makes it possible to give the ray or laser beam the correct direction thus determining the base of absolute reference with respect to which the machine will be guided for leveling and shifting the track. To perform the shift correction in a curve, the deflection of the cord materialized by rays or laser beam is measured, it is compared with the known deflection of the desired curve, and the difference is calculated to obtain the value of lateral displacement of the way one way or the other. According to conventional methods for shifting in a curve, the rope was chosen as the measurement interval in which the machine moves step by step or continuously towards the transmitter without having to change the position of the latter. The initial measurement was carried out at the intersection of the beam with the director rail or with the axis of the track, in this way there were only the arrows of the rope located on the same side of the rail. The maximum rope was of course limited by the condition that the maximum deflection did not exceed the possible lateral travel of the receiver on the machine.

In order to reduce machine downtime which makes repair work longer, which goes against the wishes of the railway companies which want the tracks to be open to traffic for as long as possible, it has been proposed in the European patent application 207197, to choose, as illustrated in Figure 1 of this application, a larger measurement interval G, which exceeds the chord MN beyond the point of intersection N of the beam with the director rail or axis of the track, up to point Q which represents, in the example chosen, the place of measurement (QQ ′) and initial correction. In this way, the measurement and working interval is extended by a distance L₂, which depending on the case may be approximately half the length L₁ of the rope MN usually used. This saves time, because the work is carried out without moving the transmitter E located at point M of the curve (fig. 1), for a working length G greater than usual. The real arrows of the different points of the NM curve are measured, they are compared in a computer with the set values and the machine is instructed to correct the current values of the arrows so that they coincide with the set values representing the theoretical position of the track. The maximum measurement interval G must of course be chosen so that the maximum sum of arrows on the left and on the right are compatible with the lateral travel of the receiver Rr which always adjusts to the beam emitted by the transmitter E.

In practice, if you are on a section of track that does not have too much curvature, you can position the carriage with the laser transmitter at the start at a distance of approximately 350 to 400 m. of the machine, therefore larger than before, and once it has advanced during work too close to the transmitter, the carriage is again moved at a distance of about 350 to 100 m. of the machine. With this measurement system, the laser transmitter is placed in the center line of the track or on the director rail and the receiver on a mobile base at the head of the machine. After each length of measurement and work, the transmitter must be advanced to a distance which varies according to the geometry of the track, positioned in the axis of the track or on the directing rail using a measuring device. distance, so that it is positioned in the consigned place in relation to the fixed point and it is adjusted in relation to the machine receiver. When positioning the transmitter, which represents a relatively long work, on the one hand the machine does not work, and on the other hand it is impossible to move on the section of the track between the transmitter and the machine so as not to hinder the adjustment work, and even after the adjustment it is impossible to move on said section so as not to interrupt the beam, which reduces the efficiency.

It is known, according to DE-A-2553318, a device for measuring a railway track comprising a laser transmitter placed next to the track and outside the gauge of free space of cars. This transmitter is installed on a pivot axis, eccentrically with respect to this axis and above it, in such a way that above this pivot axis is a large open space in the area of the point d intersection of the laser beam with this pivot axis, to allow the approach of a deflection measuring device mounted on a riper machine. The purpose of this arrangement is to create a straight line of reference between two fixed points such that said line can be followed by said deflection measuring device without interruption.

The object of the present invention is to remedy the drawbacks mentioned relating to known methods, and proposes a method for the repair of a railway track making it possible to reduce the stops of the machine and making it possible during the installation of the transmitter. the use of the section between the transmitter and the machine.

The method for repairing a railway track according to the invention is characterized by the characterizing clause of claim 1.

The advantages of the process according to the invention are linked directly to having the transmitter no longer on the axis or the guide rail of the track but next to it. Indeed, having the transmitter next to the track, allows, on the one hand to also be able to use the section of the track between the transmitter and the machine, during the installation and adjustment of the transmitter and the start of the work of the machine on the section for intermediate work or the movement of materials, and on the other hand makes it possible to lengthen the length of the measurement and work interval, especially in curves as claimed elsewhere in claim 2. In this case, being able to place the transmitter next to the track makes it possible to extend the working interval beyond the rope normally used, since the transmitter can be placed outside of the rope on the secant extending it, and therefore outside the curve. Thus, the length of the measuring and working interval is lengthened and the machine stops for moving the transmitter are reduced. When setting up the transmitter system next to the track, to the left or to the right depending on the direction of the curve, the coordinates of the transmitter are measured relative to the fixed point and these values are entered in the calculation system to obtain the values of different points on the track according to the actual position of the transmitter.

The transmitter system is positioned maximum distance next to the track which is determined, on the one hand by the available free space, i.e. not encroaching on the possible parallel track and the space which is not intersected by pylons, fences, etc. which could exist alongside the track, and on the other hand with the lateral travel of the sensor system, which is linked to the maximum lateral travel of the shifting machine.

According to a preferred variant of the invention, there are two systems of transmitters so that while the work is being carried out with the first system of transmitters, the second system of transmitters is placed on the track, defining the second interval of work so that when the machine comes close to the first transmitter system the machine is stopped to adjust the second transmitter system with respect to the receiver system. During this time, the transmitter system used until then is loaded on a carriage which brings it to the next position, without hampering the adjustment work with the next transmitter system, since this second transmitter system is found outside the track and its beam is not interrupted by the carriage when it moves on the section which is between this second system of transmitters and the machine. While moving and carrying out the positioning and adjustment of the first transmitter in its new place, the machine, after having carried out the adjustment of the transmitter system in relation to the receiver system and entered the coordinates of the transmitter system in the calculator, can start repair work. Thus, when the machine arrives near this second transmitter, the work is stopped just until the final adjustment of the first system of transmitters in its new place relative to the system of receivers while we bring with the carriage the second system of transmitters to its new place and so on.

By this process the machine downtime, which until now has been around 30% of the total working time in small radius curves, is limited to about 10% or even less, thus the efficiency of the machine is increased.

According to a preferred variant, the transport of the transmitter systems is done on a self-propelled trolley with remote control which stops automatically at the point where the transmitter system must be positioned.

The invention also relates to a device for fixing the transmitter system next to the track as defined by claims 7 to 8.

• La figure 1 est un dessin illustrant un procédé selon l'état de la technique;
• La figure 2 représente un diagramme explicatif du procédé selon l'invention;
• La figure 3 est une vue schématique illustrant le procédé selon la revendication 2 lorsqu'on se trouve sur une courbe de la voie, qui est un agrandissement d'une partie de la figure 2 vue en plan;
• La figure 4 est une vue schématique du dispositif supportant l'émetteur et indiquant les différents paramètres entrant dans le calcul pour le positionnement de différents points de la voie en fonction de la base absolue définie par l'émetteur;
• La figure 5 est une vue schématique et de face du chariot utilisé pour le déplacement du système d'émetteur.

The invention will be described in more detail using the attached drawing.

• FIG. 1 is a drawing illustrating a method according to the state of the art;
• FIG. 2 represents an explanatory diagram of the method according to the invention;
• FIG. 3 is a schematic view illustrating the method according to claim 2 when one is on a curve of the track, which is an enlargement of a part of FIG. 2 in plan view;
• FIG. 4 is a schematic view of the device supporting the transmitter and indicating the various parameters entering into the calculation for the positioning of different points of the track as a function of the absolute base defined by the transmitter;
• Figure 5 is a schematic front view of the carriage used for moving the transmitter system.

We will describe the preferred variant of the method according to the invention, namely the use of two systems of emitters of electromagnetic waves which are preferably laser emitters like that described in European patent 0090098 and which we will not describe.

As mentioned previously, up to now during the repair of a railway track, the current position of the track is measured in relation to an absolute reference base, it is compared by means of a calculation system, to the theoretical coordinates recorded during the laying of the track, and the machine is ordered to correct the position of the track both in height (leveling) and laterally (shifting). We will not go into detail on how to carry out the measurements and the corrections as it is described in the two above-mentioned documents.

For convenience, we will no longer speak of a system of transmitters or receivers but only of a transmitter or a receiver which can advantageously be those described in European patent 090098.

The Applicant's new process in its preferred form is shown in Figures 2 to 4.

By arranging according to the method, the transmitter always next to the track allows, as mentioned previously both during work as well as the positioning and adjustment of the transmitter to a new position, to use the section of the track For transport. Another advantage is that when the repair work is done in a curve of the track the fact of placing the transmitter next to the track lengthens the length of the work interval.

In fact, we have seen that by placing the transmitter E₁ (fig. 2) next to the track, this makes it possible to lengthen the working interval and to measure by a value L₃ which can be, depending on the parameters previously mentioned, approximately 50% of the length L₁ of the cord M₁ N₁.

Placing the transmitter always next to the channel also makes it possible to alternately use two transmitter systems as will be explained below with the aid of FIG. 2.

At the start, we have the first transmitter E dispose at position B next to the track, we measure the coordinates relative to the corresponding fixed point and we enter them into the calculation system to define the absolute reference base for the first measurement interval and working P₁, by means of the beam of the transmitter E₁, as will be described later on with the aid of FIG. 4. After having made the appropriate adjustments, the machine 1 advances on track V until the receiver Rr arrives at point A, which is the point closest to the transmitter E₁, located at point B, allowing measurements to be made. The first working interval P₁ is thus traversed.

While the machine 1 is working on the interval P₁, the second transmitter E₂ is positioned at a point B₁, and its coordinates are measured relative to the corresponding fixed point to define the absolute reference base for the second measurement and working interval P₂. When machine 1 comes to the end of the interval P₁, either at point A, it is stopped and the transmitter E₁ is loaded on a self-propelled carriage 2 to be driven to a position B₂. The final adjustment of the transmitter E₂ is made with respect to the receiver Rr and the repair work begins in the second measurement and work interval P₂ defined by the points A and A₁ even if the carriage 2 is still on the section of the channel V corresponding to this second interval. Thus, the time for stopping the machine is reduced only to the final adjustment of the transmitter relative to the receiver, the movement, the positioning and the measurements of its coordinates having been carried out while the machine 1 was working on interval P₁.

While the machine is working on the interval P₂, the carriage 2 with the emitter E₁ is led to the point B₂ where it stops automatically, and the emitter E₁ is put in place, at the measurement of its coordinates relative to the corresponding fixed point. Thus, when the machine arrives at point A₁, it is stopped, it is loaded onto the carriage 2, which has returned close to it, the transmitter E₂, and it leaves to bring it to a point B₃ (not shown) for that the emitter E de located at point B₂ is adjusted relative to the receiver Rr located at point A₁. Then we start the repair work on the section P₃ and so on.

By means of these two transmitters which are always placed next to the track, the idle times of the machine are reduced to approximately 10% of the total working time in small radius curves, while with conventional systems are about 30%. When working on straight sections the machine downtime is reduced to less than 5%.

It is understood that the length of each working and measuring interval P₁, P₂, P₃, etc. depends on the configuration of the terrain and the track so that the rays emitted by the E₁ or E₂ transmitter are not interrupted by pylons, fences, etc., and in particular, on the curves they are based on the maximum displacement possible from the shift receiver. Thus, in Figure 2, the two intervals P₂, P₃ are of different length because as shown in Figure 3, P₃ is on a curve.

Depending on the configuration of the platform, the transmitter is placed on the left or right of the track but in any case in the curves the transmitter is always placed outside the arc (fig. 3)

In Figure 4, there is shown schematically, the device supporting a transmitter E next to the channel and the different setpoint coordinates and relating to a fixed point F for the determination of the absolute reference base. Beforehand, we will describe the device supporting the transmitter E.

It comprises a base 7 placed on crosspieces 3 and provided at one end with a clamp 8, making it possible to attach it to a file of adjacent rails 5. On this base 7, an axis 9 is arranged to which is articulated a support 10 provided with a column 11. The articulation 9 can be moved in the horizontal plane by means of a screw not shown, making it possible to move the distance meter D as well as the emitter E with respect to the theoretical axis of the channel. The support 10 carrying the distance meter D and the transmitter E which are on the same axis, can be placed vertically using the screw 12.

On the column 11 is mounted a sliding piece 13 secured to a nut 14 collaborating with a screw 15 parallel to the column 11. The lower end of the screw 15 rests against a thrust bearing 16 secured to the column 11. A piece 17 mounted at right angles to the sliding piece 13 serves to support the transmitter E. The screw 15 is used to adjust the height of the transmitter E. Finally, on the upper end 18 of the column 11 and in the axis a distance meter D is fixed to the transmitter E. It is obvious that two such supports are used for each of the transmitters E₁, E₂.

The determination of the absolute reference base is carried out as follows (fig. 4).

The transmitter E is placed with its support device facing a fixed point F which in the present case is materialized on a pylon 19 next to the platform of the track. After having put the support for the transmitter E and distance meter D vertically by means of the screw 12, we measure by means of the distance meter the values R _M which is the horizontal distance between the fixed point F and the distance meter D and N _M which is the height between the axis of the distance meter and the fixed point F. The height N and the distance R of the theoretical axis of the channel 6 with respect to the fixed point F are known and recorded. To determine the working position of the emitter E with respect to the theoretical axis 6, the difference R _L = R - R _M or R _L = R ′ _M - R is calculated in the case where the emitter E is placed on the other side of the track and the height N _L as a function of the geometry and the lifting height of the track. In the curve, the value N _L must be corrected according to the slope. Before the repair, the theoretical axis 6 rarely coincides with the axis of the track.

The values R _L and N _L are entered into the calculation system which indicates the direction of the beam of the transmitter and will subsequently indicate the corrections to be made taking into account the position of the transmitter E.

In Figure 5, there is schematically shown the carriage 2 for successively transporting the transmitters E₁ and E₂ with their supports from one position to the other B₁, B₂, B₃. etc.

It includes a bracket 20 with a lifting system 21 provided with a hook 22. This carriage 2 is preferably self-propelled with remote control, automatically stopping at the desired location.

Claims (3)

1. A process for the repair of a railraod track by using, on the one hand, an emitter system emitting electromagnetic rays (E₁, E₂), especially laser rays, which generates beams defining an absolute measurement base and, on the other hand, a levelling and track-shifting machine (1), equipped with a system of receivers (Rr) for these beams, as well as a system for determining the track-shifting and levelling corrections to be made, which are derived from the set values of the coordinates of the railroad relative to the absolute measurement base, and from the actual coordinates of the position of the track at the start of the work, the emitter system (E₁; E₂) being installed in front of the machine (1) at a specified distance at a position specified in relation to a fixed reference point (F), this distance defining the measurement and operating interval (P₁, P₂, P₃) which is then traversed by the machine (1), at the end of the traverse of said interval (P₁, P₂, P₃), the work being interrupted in order to advance the emitter system (E₁, E₂) to the next measurement and operating interval, which will be traversed by the machine (1) and so on, the lateral offset (R_L) and vertical offset (N_L) of the emitter system relative to the theoretical axis (6) of the track (V) being measured and introduced into the system for determining the corrections to be made, characterized in that the emitter system (E₁, E₂) is placed on each occasion at the side of the track (V), in that in a curve (A′₁, A′₂) of the track (V), the electromagnetic rays define a chord (N₁, M₁) of this curve and the emitter system is placed outside this chord (N₁, M₁) on the secant extending it, and thus outside the curve (A′₁, A′₂) to extend the length of the measurement and operating interval (P₃), in that the emitter system (E₁, E₂) is placed either to the left or to the right of the axis (6) of the track (V) as a function of the sense of the curve (A′₁, A′₂), in that the lateral distance between the emitter system and the track does not exceed a maximum distance (A₂, A′₂) determined by the free space available and compatible with the lateral travel of the system of receivers (Rr), and in that the system of receivers (Rr) is placed on the secant of the curve (A′₁, A′₂) either outside or inside of the chord (N₁, M₁).

2. A process as claimed in claim 1, characterized in that use is made of two emitter systems (E₁, E₂) placed outside the track, permitting the transport of the emitter out of service within the operating interval without disturbing the operation of the emitter in service.

3. A process as claimed in one of claims 1 or 2, characterized in that the transport of the emitter system (E₁, E₂) is undertaken on a remotely controlled self-propelled carriage (2).

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