EP0315704B1 - Rail grinding machine for reprofiling railheads - Google Patents

Abstract

The machine which comprises serveral grinding heads per stretch of rail and which may be moved with respect to height by means of lifting devices is equipped with an installation for automatically lifting grinding wheels (M1to M8) in the critical zones of switches, namely frog and blade zones. This installation comprises, on either side of each stretch of rail (R1, R2), a pair of sensors (C1, C2, C3, C4) at the front and a pair of sensors (C'1, C'2, C'3, C'4) at the rear, detecting the starts of critical zones, therefore the widening of the running tread in the zone of a switch and/or their auxiliary parts adjacent to the rails; a computation unit connected, on the one hand, to the sensors and, on the other hand, to each lifting device and equipped with a memory containing all the data defining the lifting distances of each grinding head in the critical zones; a unit for measuring the path traveled connected to the computation unit; the computation unit is provided in order to command the lifting and the lowering of each grinding head independently, over memorized distances, as a function of signals received by the sensors.

Description

The invention relates to a grinding machine for the reprofiling of rail mushrooms equipped with at least one grinding head per row of rails movable in height by at least one lifting device which can be controlled automatically.

A grinding machine of this type, for example, as described in German patent DE 28 43 649 of the applicant, allows the elimination of corrugations and reprofiling of the rails, and is equipped with grinding wheels for the complete machining of the running surface, as well as spokes and external and internal faces of the rails. This machine can be fitted with peripheral wheels or cup wheels.

Another machine for reprofiling the rail head fungus equipped with cup wheels is described in European patent EP 0 125 348 of the applicant.

Finally, a car for measuring and rectifying the profile of a rail head using cup wheels is known from European patent application 87101477 by the applicant. The operation of this car is such that each grinding head is lifted automatically from the rail which it has rectified if the facet obtained from the profile corresponds to the set profile. For this purpose, sensors are provided which measure the distances between a reference base of the machine and the surface of the rail which is being rectified by a grinding head; when the sensors signal that the actual distance values correspond to the setpoint values stored in an analyzer, the latter issues an order to a control unit which automatically raises the grinding head concerned to the off-working position.

Automatic grinding operations are carried out without problems along sections having only rails, without switches and crossings. However, when the grinding car comes close to the track devices, especially in the core and at the entrance of the switch blade, where the width of the rolling surface varies, it is necessary to lift the grinding wheels on well-determined distances to avoid damaging these areas. Likewise, if there are obstacles in the way of the grinding wheels, the grinding wheels must also be lifted to avoid their destruction. This can be the case, in particular, if one works with cup wheels when these pass against the rails of a switch.

To take these problems into account, currently, grinding cars are equipped either with magnetic sensors, or with devices for measuring the distance traveled to control the lifting of the grinding wheels throughout the area of a track device. The magnetic sensors, mounted on the grinding carriages, are activated by magnets placed beforehand along the track. Lifting the grinding wheels using the distance-measuring devices requires programming of the grinding path before work. These two control systems have many disadvantages, on the one hand, because it is necessary to reserve fairly large safety distances before and after the areas of the switches and crossings, this results in relatively large unmilled areas, on the other hand, with grinding machines or carts used until now, all the grinding wheels rise or descend at the same time, which also increases the safety distances to be observed. Each variation of the grinding path requires a new programming of the measuring installation, respectively the displacement of all the magnets.

The object of the present invention is to limit the width of the non-ground area and to facilitate the preparation of work and the control of the lifting of the grinding wheels in critical areas.

This object is achieved by the features of claim 1.

The first advantages result first of all from the fact that the sensors make it possible to recognize and distinguish automatically the blade and the core, and consequently to interrupt the grinding only in the critical zones of blade and heart while between these zones , the grindstones are lowered and working. At the same time, the length of the non-ground area is reduced to a minimum. In addition, the preparation work is eliminated, work which was until then necessary either by the installation of the magnets, or by the programming of the grinding course.

Under the terms critical zone, we mean first of all the zones where the non-lifted grindstones can damage parts of a track apparatus, for example the widening of the running surface or the adjacent parts of the rails; furthermore, these terms also include areas in which obstacles may be in the path of the grinding wheels and risk damaging them.

Furthermore, according to the invention, the control program makes it easy, for a machine with several grinding heads, to raise and lower successively the grinding heads each at a well determined location, and offset with respect to the neighbor to avoid creation sharp ramps which would occur if all the grinding wheels started machining in the same place; we can therefore create a perfect continuous connection between the ground and non-ground area.

The memorized control program is preferably such that it includes, for each switchgear concerned, only the data defining the lifting distances of the grinding heads for the two critical zones, namely the blade zone and the core zone, but not for the intermediate zone, between two critical zones, where grinding can be carried out; it is the activation of one or more of the sensors concerned which detects the start of the first critical zone and then of the second critical zone of this switchgear and which starts each time the program giving the lifting distance in the zone concerned .

The program can also be modified such that, for each type of track device, not only are the lengths of the two critical zones where the grinding wheels are to be lifted, but also the length of the intermediate zone, therefore the grinding zone, where the grindstones have come down. In this case, the entire program comprising the complete track device is triggered by the concerned sensor (s) when the latter detects the start of the track device; the sensors then remain inactive along the switchgear since all lifting and lowering lengths are programmed. For this command, the measurement of the distance traveled between two critical zones is essential, and the accuracy of the measurements which must be made makes this type of command useful, preferably, for short track devices, while for long devices way it is best to use the first type of program mentioned.

Preferred embodiments result from the dependent claims.

The accompanying drawings show, by way of example, embodiments of the invention.

Figure 1 is a side view of a machine grinding machine according to the invention equipped with a grinding carriage carrying four grinding heads per line of rails with peripheral wheels.

FIG. 2 is a schematic profile view of the grinding carriage according to FIG. 1.

Figure 3 is a top view.

FIGS. 4a and 4b schematically represent a sectional view of the sensors at the level of the critical zone of the switchboard blade for the two rows of rails at the location I indicated in broken lines in FIG. 7.

FIGS. 5a and 5b show similar views in section at the level of the heart, at location II indicated in broken lines in FIG. 7.

FIG. 5c represents a similar sectional view of a variant in which the counter-rail, in the core zone, is detected.

Figure 6 is a block diagram showing the lifting of two consecutive grinding wheels above a critical area A-B.

Figure 7 is a schematic top view of a track device with the indications of the lifting zones of the different grinding wheels, in the case where the alignment V1 is traversed.

Figure 8 is a similar view of the switchgear according to Figure 7 in the case where the deviation V2 is traveled.

FIG. 9a schematically illustrates an example of the extent of the facets machined by the peripheral grinders M1 to M4 on a rail.

FIG. 9b schematically represents, for the case of grinding with cup wheels, an example of the position of the wheels M′5 to M′8 on a rail.

Figure 10 shows a block diagram of the control device.

FIG. 1 schematically represents a grinding machine formed from a single grinding car 2, with two axles 3, movable on track 1 and provided with a grinding carriage 4, equipped with grinding heads 5. This grinding carriage 4, as shown diagrammatically on a larger scale in FIGS. 2 and 3, is supported by two axles 6, and comprises on each rail file R1, R2 four grinding heads 5 each supporting a peripheral grinding wheel M1, M2, M3, M4, respectively M5, M6, M7, M8. The grinding heads 5 can be lifted individually by lifting devices 10 (Figure 1). Pads 7, which remain in contact with the surface of the rail during grinding, are provided between the grinding wheels M1 to M4, respectively M5 to M8.

At each end of the grinding carriage 4 are mounted sensors C1 to C4, respectively C′1 to C′4. The sensors C1 to C4 operate in forward direction, according to the arrow indicated in FIG. 2, and the sensors C′1 to C′4 operate in reverse direction. The sensors are mounted in pairs, each pair comprising a sensor placed outside the rail C1, C2, C′1, C′2 and a sensor placed inside the rail C3, C4, C′3, C ′ 4. The pairs of sensors are supported by pads 11 intended to slide on the surface of the rails, as can be seen, for example, in FIGS. 4a, 4b. Instead of being mounted on skids, they can be mounted directly on the axles 6.

The distances between the front sensors C1 to C4 and the different grinding wheels are respectively called L1 for the grinding wheel M4, respectively M8, L2 for the grinding wheel M3, respectively M7, L3 for the grinding wheel M2, respectively M6 and L4 for the grinding wheel M1, respectively M5. The corresponding distances between the grinding wheels M1 to M4, respectively M5 to M8, and the rear sensors C′1 to C′4 which play a role if the car is traveling in reverse, are not shown in the figure.

To better explain the arrangement and functions of these sensors, reference is made to FIG. 7 where a switch is shown with the indication of the ground and non-ground zones and, on the left, the position of the sensors C1 to C4, just before the start of the switch. In this figure 7, we see the rails R1 and R2 of the alignment V1, the blade Z, the rails R3 and R4 of the deflection V2, the counter-rails T and the core H. The zones M correspond to the grinding zones , the zone LZ corresponds to the non-ground zone in the region of the blade Z, the zone LH corresponds to the non-ground zone in the region of the core H.

The sensors C1 or C2, respectively C'1 or C'2, placed outside the rail detect, when they pass the blade zone LZ, the widening of the rolling surface in the blade Z, as illustrated in FIGS. 4a and 4b for the location I indicated in broken lines in FIG. 7 and for the case where the car traverses the alignment V1. Under these conditions, it is only the sensor C2 (FIG. 4b) which is activated, because it detects, on the outer side of the rail R2, the widening of the rolling surface at the start of the diversion branching. with the R4 rail. On the other hand, neither the sensor C4, nor the sensors C1 and C3 along the rail R1 (FIG. 4a) are activated because the blade is distant from the rail R1.

When the car travels the deviation V2, (figure 8), it is only the sensor C1 which is activated.

To detect the core zone LH, it is possible to use either the presence of the interior parts of the core H, or the presence of one of the counter-rails T; in both cases, in addition to the external sensors, the sensors C3, C4, respectively C'3, C'4 placed inside the rail are also used.

FIGS. 5a and 5b show the situation in the middle of the core H, at location II indicated in broken lines in FIG. 7, in the case where the internal parts, respectively the widening of the rolling surface in the core H, are detected on the rail R2 by the two sensors C2 and C4 which are activated (Figure 5b). The sensors C1 and C3, on the rail R1, remain inactive, as illustrated in FIG. 5a.

When the car travels the deviation V2 (figure 8), it is the sensors C1 and C3 which are activated while the sensors C2, C4 remain inactive.

So, when the inner parts of the core H are detected, these are the two sensors C1 and C3 which work together if the deviation V2 is traversed, while these are the two sensors C2 and C4 which work together if the alignment V1 is traversed .

FIG. 5c shows the variant for detecting the core zone H. In this case, the interior sensors, in this case, according to FIG. 5c, the sensor C3 on the rail R1, is mounted so that it responds to the presence of the counter-rail T, and in this way announces the presence of a core zone H. So, in this case, the two sensors C1 and C4 are used during the passage of the deflection V2 and the two sensors C2, C3 when passing the alignment V1.

In this way, the one or those of the sensors which responds when approaching a switchgear defines in which direction the switchgear is traversed; from the blade to the heart or from the heart to the blade.

Sensors without known contacts are preferably used, for example of the inductive, pneumatic or sonar type, which must be capable of detecting the presence of the material of the rails, that is to say if the distance between the material of the rails and the sensor is less than a minimum value, the sensor emits a signal. It is also in principle possible to use mechanical sensors which come into contact with the enlarged surfaces of the rails, respectively with the auxiliary parts, in the core and possibly blade zones.

The sensors C1 to C4 and C'1 to C'4 are connected to a calculation unit 8, illustrated diagrammatically in FIG. 10, which shows the block diagram of the device. These sensors control the calculation unit 8, which also receives a signal corresponding to the distance traveled emitted by a measurement unit of the distance traveled 9. The calculation unit 8 in turn controls all the lifting devices 10 for the heads of grinding, to raise or lower the various grinding wheels M1 to M8 concerned. This command is carried out according to a program established for the blade and the core of each type of switchgear to be corrected during a journey.

The calculation unit 8 is therefore programmed beforehand as a function of the type of track device to be corrected. The data are entered to define the lifting distances corresponding to the length of the blade and the core as a function of the direction of work, and this for each wheel head. In this way, it is possible to determine which wheels are to be lifted in the blades and hearts and in what succession they must be lifted. Programming the unit switchgear calculation is carried out before or during work. The type of switchgear is entered regardless of the direction of travel. When several switches are to be ground, it is only necessary to observe how the different types succeed one another. The calculation unit 8, in relation to the signals received from the sensors concerned, automatically determines in this way the direction of work either in the blade-to-core direction or vice versa, according to the control signals from the sensors outside. and inside the rails, as already explained.

The principle of control by means of the sensors and of the control unit 8 consists in that the sensors only serve to detect the start of the critical zones and, thereby, to start the program incorporated in the calculation unit 8 for the type of switchway concerned. This program defines when, depending on the sensor signal, each grinding head must be lifted individually and where it must be lowered again for the grinding work to continue. This means that the succession, one after the other, of each grinding head is programmed according to the type of switchgear and the length of the critical zones. The program containing only data of stored lengths, it is necessary, to carry out the command of the grinding heads, to introduce into the calculation unit the distances traveled measured by the unit 9. The path traveled can also be determined indirectly at from the measured speed and time.

The principle of control of the individual grinding wheels is illustrated diagrammatically in FIG. 6 for, as for example, the control of the two grinding wheels 7 and 8 by the sensor C2. We see a portion of the track on which two points A and B have been defined located on the rail R2 and determining a critical area. At point A, the sensor C2 detects, for example, the widening of the raceway, while at point B, this same sensor C2 is no longer activated because the width of the rail R2 has returned to normal. When the sensor C2 is activated at point A, it controls the calculating unit 8 whose program concerned is started and which in turn controls the lifting device 10 so that the grinding wheel M8, after the distance traveled S1, and the grinding wheel M7, after the distance traveled S2, are lifted, these grindstones then being lowered after the distance L (M8), respectively L (M7). Preferably, the distances L (M7) and L (M8) do not have the same value, as illustrated, to arrive at a continuous connection between the ground and non-ground areas and to avoid sharp ramps which might occur if the lifting or lowering of all the wheels was done at the same point.

The distances S1, S2, determining the place of lifting of the grinding wheels after the activation of the sensor C2, are calculated as a function of the distances L1, L2 between the grinding wheels and this sensor and are previously introduced into the program of the unit of calculation. The distances S1, S2 are chosen so that the length E1 = L1 - S1, respectively E2 = L2 - S2, therefore the distances between the place where the sensor responds and the place where the grinding wheels are lifted, allows to respect sufficient safety margin and allows shifting of the lifting points. The distances E1, E2 are generally not the same for the two directions of passage of a switchgear. For for this reason, the data E1, E2 which determine S1, S2 generally have different values depending on the directions of blade to core or core to blade and, as already mentioned, this direction is detected by the sensors concerned so that the correct program is chosen . The distances L (M7) and L (M8) during which the grinding wheels are lifted depend on the type of switchway considered and are also programmed in the calculation unit independently of the direction of travel, respecting the offset of the start of grinding for each wheel.

By the command described, it is possible to reduce the unground surfaces to a minimum length. The program also allows, in a core or blade area, to raise only among the grinding heads, those which could damage the widenings and other parts of the switchgear.

FIG. 9a shows an example of an arrangement of the peripheral grinding wheels, indicating the widths of the facets machined by the grinding wheels M1 to M4 on the rail R1. It has been assumed that the grinding wheels M3 and M4 only rectify the outer faces of the rails while the grinding wheel M2 rectifies the central rolling surface of the rails and that the grinding wheel M1 grinds the internal face.

Figures 7 and 8 illustrate an example of how the different grinding wheels are controlled by assuming the distribution of the grinding wheels as explained in relation to Figure 9a and also assuming that the grinding wheels M7, M8 grind the outer faces of the rails, the grinding wheel M6 grinds the running surface and the grinding wheel M5 grinds the internal face. When grinding a track device, as illustrated in figures 7 and 8, the grinding car must make two courses, one for grinding the alignment V1 (figure 7), the other for grinding the deviation V2 (figure 8). Before crossing the switchgear with the car, the type of switchgear to be ground must be entered in the calculation unit. All the other commands are then executed automatically and independently of the direction of travel.

In the example according to FIGS. 7 and 8, it has been assumed that the types of grinding wheels used, therefore peripheral grinding wheels, are such that the blade Z, in its position remote from the rail, as well as the counter-rails T in the area of core H, are outside the size of all the grinding wheels and are not affected.

This is why, in the alignment V1, illustrated in FIG. 7, the sensors C1 and C3 remain inactive on the rail R1 during the entire journey and this rail R1 is therefore completely ground by the grinding wheels M1 to M4 which are not lifted.

On the rail R2, in the blade zone LZ, if the alignment V1 is traversed, the external sensor C2 is activated (FIG. 4b) and controls the computing unit 8 to lift the external grinding wheels M7 and M8 over the distances L (M7), respectively L (M8), after which they descend to grind the zone M. In the core zone LH, the sensors C2 and C4 are activated (FIG. 5b) and control the lifting of all the grindstones M5 to M8 over the distances L (M5) to L (M8) respectively. As shown schematically in Figure 7, the lifting and lowering of the grinding wheels is done successively and in an offset manner to obtain a continuous and perfect connection between the ground areas M and areas LZ and LH not ground.

In the deviation V2, illustrated in FIG. 8, the sensors C2 and C4 remain inactive and the rail R4 is therefore completely ground by the grindstones M5 to M8. On the other hand, on the rail R3 the sensor C1 is activated in the blade zone LZ, and it is only the external grindstones M3 and M4 which are lifted. In the LH core zone the two sensors C1 and C3 are activated and thus control the lifting of all the grinding wheels M1 to M4. Of course, the different grinding wheels are again lifted and lowered successively and in an offset manner, although this is not illustrated in FIG. 8 for reasons of simplification.

According to the invention, it is also planned to incorporate into the program the lengths of any places where there are obstacles for the free passage of one or more grinding wheels in the working position, so that these are lifted to prevent damage.

While in the case of using peripheral grinding wheels, as was the case in the embodiment which has just been described in detail, there are generally no such obstacles, on the other hand, in the case of use of cup wheels, these obstacles may exist. FIG. 9b schematically shows the distribution of four cup wheels M′5 to M′8 on a rail, the wheels M′7 and M′8 rectify the external faces of the rail, while the wheel M′6 corrects the running surface central and the grinding wheel M′5 corrects the internal face. Referring to FIGS. 5a or 5c, it is easy to imagine that the counter-rail T can constitute an obstacle for cup wheels, and in this case, it is also necessary to provide for lifting the grinding wheels concerned when passing through the zone having a counter rail. The blades in their positions remote from the rail can also form such an obstacle for cup wheels.

In the example considered, the control program was such that the sensors concerned started the program at the start of each critical zone of a switchgear. This program therefore contained only the stored lifting distances. As mentioned in the introduction, it is also possible in principle to provide a program in which the complete track device is stored, comprising the two lifting zones and the intermediate descent zone, in this case the complete program for a track device. is engaged when the relevant sensor detects the start of this switchgear.

In principle, the invention also applies to the case where a single grinding head is used with a single grinding wheel, the working orientation of which is modified during several passages to obtain complete grinding. However, in general, the grinding machine comprises several grinding heads which can also be distributed on two or more grinding carriages, or even comprise two or more coupled grinding cars. In all cases, it is sufficient to provide two sensors per rail line at the start of the machine, respectively of the first grinding car, and two sensors per rail line at the end, and the individual control of all the grinding wheels of the different trolleys or cars is carried out by the program triggered by the sensors. If all the wheels belonging to a carriage must be lifted in a critical area, it is also possible to provide a control which lifts and lowers the entire carriage with all of the wheels.

The invention is not limited to the example described, but many variants could be envisaged, especially with regard to the type of sensors.

Claims (10)

1. A grinding machine for reprofiling railheads equipped with at least one grinding head (5) per stretch of rail which may be moved in respect of height by at least one lifting device (10) which may be commanded automatically, characterized in that it is equipped with an installation for automatically lifting the grinding wheels in the critical zones of the switch gears, zones of the blade (Z) and of the frog (H), comprising

   - at least two sensors (C1, C3; C2, C4), per stretch of rail (R1, R2), installed before all the grinding heads (5), in the direction of travel, a sensor (C1, C2) on the outside, the other (C3, C4) on the inside of the rail (R1, R2) and which are capable of detecting the widening of the running tread in the zone of a switch gear and/or their auxiliary parts adjacent to the rails, and of issuing a signal in this case;

   - a computation unit (8) whose inputs are connected to the sensors (C1 to C4) and whose outputs are connected to each lifting device (10), and which is equipped with a memory in which all the data defining the lifting distances of each grinding head in the critical zones of the type or of the various types of switch gears in question, in their order of sequence, are memorized, thereby representing a program for commanding the grinding heads;

   - a unit (9) for measuring the path traveled connected to the sensors (C1 to C4) and the computation unit (8),

   this computation unit (8) being arranged in order to command the lifting and the lowering of each grinding head (5) independentely of the others over distances which are predetermined according to the type of switch gears in question as a function of the signals of various sensors, of the memorized data as well as of the path traveled.
2. The machine according to claim 1, characterized in that two pairs of sensors (C1, C3; C'1, C'3; C2, C4; C'2, C'4) are provided per stretch of rail (R1, R2) and which are fixed at the front and at the rear of the assembly of grinding heads (5), one pair operating in forward travel and one pair operating in reverse travel.
3. The machine according to claims 1 and 2, characterized in that the outer sensors (C1, C2; C'1, C'2) are capable of detecting the widening of the running tread in the blade and in the frog.
4. The machine according to claims 1 to 3, characterized in that the inner sensors (C3, C4; C'3, C'4) are capable of detecting the inner parts of the frog (H).
5. The machine according to claims 1 to 3, characterized in that the inner sensors (C3, C4; C'3, C'4) are capable of detecting the guard rails (T).
6. The machine according to one of claims 1 to 5, characterized in that the sensors are inductive sensors.
7. The machine according to one of claims 1 to 5, characterized in that the sensors are sonar sensors.
8. The machine according to one of claims 1 to 5, characterized in that the sensors are pneumatic sensors.
9. The machine according to one of claims 1 to 8, having several grinding heads, characterized in that the command program provides the lifting and the lowering of the grinding heads in question in a successive and offset manner.
10. The machine according to one of claims 1 to 9, characterized in that the command program also comprises data defining the distance of the grinding zone of each grinding head between two critical zones of a switch gear.

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