Patent Application
20220388551
The present patent disclosure concerns a method of placing a sensor device on a rail track, the sensor device for placement on a rail track, and an assembly comprising the sensor and the rail track.
Sensor devices exist that are placed on a rail track for sensing various properties of the rail track and/or passing trains. Such sensor devices are commonly placed by providing holes in the rail track and attaching the sensor device to the rail track using fasteners such as nuts and bolts.
As described in patent document NL 2023451, filed 5 Jul. 2019 by the same inventors as the present disclosure and unpublished at time of filing of the present disclosure, when placing a sensor device on a rail track, it is an option to use magnets in the sensor device to attach the sensor to the rail track, which is generally made of steel. Sensor devices exist for sensing certain properties of rail vehicle wheels passing by on the rail track.
Although dimensions of rail tracks differ to some extent, rail tracks in general when viewed in cross section comprise a base portion, a head portion, and a neck portion connecting the base portion and the head portion. The head portion is for receiving the wheels of rail vehicles. The head portion is typically referred to as the “head”, the neck portion as the “web” and the base portion as the “foot”.
Attaching the sensor device using magnets may result in unwanted movement of the sensor device, which may have unwanted effects on the measurements performed by the sensor. Also, the sensor may be damaged by passing rail vehicles if it is accidentally moved to a position overlapping with an area or volume through which the rail vehicle wheels pass.
Also, due to safety and other regulations, an object such as a sensor that is placed on a rail track in many countries must remain at a minimum distance from the inner rims of the wheels of passing rail vehicles. In the Netherlands, for example, this minimum distance is 45 mm.
It is an object, among objects, of the present patent disclosure to provide an improved sensor that is attached to a rail track magnetically and an improved method of attaching a sensor to a rail track.
According to a first aspect, there is provided a sensor device configured to be placed on a lateral side of a rail track, the sensor device comprising:
The above sensor device, when placed onto the rail track, in particular with the second and third contact edge regions onto the neck portion thereof such that the first contact edge region is in contact with the head portion (or the base portion), beneficially has the three contact edge regions in contact with the rail track, resulting in a very stable attachment of the sensor device to the rail track.
In addition, the first contact edge portion is positioned relative to the second and third contact edge portions such that when the device is placed there is only one position on the rail track that the device can take. This results in a well-defined relative position between the sensor device and the rail track. For example, the top side of the sensor device will have a well-defined distance from the top of the head portion of the rail track.
The first contact edge region, which is preferably at the head portion side of the rail, is positioned such that it is in contact with a bottom side of the head portion of the rail track. This beneficially results in the sensor device to remain below a well-defined level compared to the rail track.
The device can thus be precisely placed onto the rail track, without the need of precision measurements or specifically trained technicians for placing the sensor devices.
When viewed in cross section, the first, second and third contact edge regions form a triangular shape. The outward position of the second contact edge region means that compared to the first plane, the second contact edge region is positioned towards the outside of the housing.
The device is configured by making use of the standardized shape of rail tracks. The device is configured to be placed on the neck portion with the second and third contact edge portions. The neck portion in most types of rail tracks has a concave surface of which the radius of curvature decreases towards the head portion.
The sensor device is in particular beneficial when provided with sensors configured to measure a value associated with a magnetic field, such as a magnetic field strength and/or direction or change in the magnetic field strength and/or direction. Using the above sensor device, the sensors can be placed as close as possible (e.g. within limits set by safety standards) to the top of the rail, thereby being as close as possible to a passing (wheel of) a rail vehicle. However, the sensor device can alternatively or additionally comprise other sensors to measure some property of a passing rail vehicle or some property that is influenced by such a passing rail vehicle. The sensor device can therefore be any one or any combination of: a magnetic field sensor, an optical sensor, an electric field sensor, an electric potential sensor, an electric current sensor, an acoustic sensor, a vibration sensor, a position sensor, a thermal sensor, a proximity sensor, a radar sensor, and a chemical sensor. The magnetic field sensor may include a magnetometer (e.g. a MEMS magnetic field sensor), a Hall effect sensors, a magnetic anomaly detector, and/or a magnetoresistance sensor.
It is preferred that the first contact edge portion is at the side of the head portion of the rail track. However, it will be understood that the precise placement can also be achieved when the first contact edge portion is positioned at the side of the base portion of the rail track. In that configuration, the base side of the sensor would then be positioned at the head portion. Alternatively, the base side would then be the top side and the top side would then be the base side.
In an embodiment, when viewed in cross section, the neck portion has a first width, the head portion has a second width and the base portion has a third width, the first width being smaller than both the second width and the third width, wherein preferably the first, second and third widths are respective first, second and third maximum widths, wherein the wherein the housing is configured such that when the second and third contact edge regions are in contact with the neck portion, the first contact edge region is in contact with either the head portion or the base portion. The outer surfaces of the neck portion may have a concave surface profile having a radius of curvature that decreases towards the head portion, wherein side walls of the head portion have a concave surface profile having a radius of curvature that increases in a direction away from the neck portion.
Further embodiments of the sensor device are defined in the dependent claims, the advantages of which will become apparent form the below description of figures.
According to a second aspect, there is provided a method of placing a sensor device according to any one of the preceding claims on a lateral side of a rail track, the method comprising:
In an embodiment, the sensor device is placed with the second and third contact edge regions in contact with the lateral side of the rail track; and
The alternative is to first place the first and second contact edge regions in contact with the rail track, and thereafter sliding the sensor device in a direction such that the third contact edge region moves closer to the neck portion of the rail track until it finally touches the rail track.
This method has the advantage that the sensor device is always placed in the same reproducible position relative to the rail track.
In an embodiment, the rail track in cross section comprises a base portion, a head portion for receiving wheels of rail vehicles, and a neck portion connecting the base portion and the head portion, wherein the second and third contact edge regions are placed in contact with a surface of the neck portion of the rail track.
It is preferred that the sliding direction is towards the head portion such that after sliding the first contact edge region is placed in contact with a base portion facing surface of the head portion.
According to a third aspect, there is provided an assembly or system comprising a sensor device according to the first aspect at least one rail track.
Features, advantages and effects of the various aspects are readily applicable to any of the other aspects, as will be understood, also by a person skilled in the art.
The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of devices of the present disclosure. The above and other advantages of the features and objects of the disclosure will become more apparent and the aspects and embodiments will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which:
As shown in
The sensor device 1, as can be seen in
The mounting side 14 comprises a first 20, a second 22 and a third 23 contact edge region. The sensor device 1 comprises a permanent magnet 8 positioned such that the sensor device 1 is mountable on the lateral side of the rail track by magnetic attraction between the magnets and the rail track. The magnet 8 may extend along a longitudinal direction of the housing 9, viz. along the z-direction indicated in
The second contact edge region 22 is positioned outwardly from a first plane 200 extending through both the first contact edge region 20 and the third contact edge region 24. The second contact edge region 22 is further positioned between a second plane 202 extending parallel to the top side 10 and through the first contact edge region 20 and a third plane 204 extending parallel to the second plane 202 and through the third contact edge region 24. In this embodiment of the sensor device 1, the third plane 204 extends parallel to the base side 12.
The housing 9 is configured such that, when the sensor device 1 is placed on the rail track, at most the first 20, second 22 and third 24 contact edge regions are in contact with the rail track.
In certain variants of the sensor device 1, the mounting side 14 comprises a side portion 32 positioned at a lateral side of the housing 9 and connecting the second contact edge region 22 and the third contact edge region 24, and a slanted surface 30 between the top side 10 and the side surface 32. Herein, the first contact edge region 20 is an edge region between the top side 10 and the slanted surface 30, the second contact edge region 22 is an edge region between the side surface 32 and the slanted surface 30, and the third contact edge region 24 is an edge region between the side surface 32 and the base side 12.
It will be understood that the slanted surface 30 can alternatively be replaced by any other shape, as long as it not in mechanical contact the rail track 2 when the device is in a mounted position.
As shown in
A fourth plane 206 extends through the first contact edge region 20 and is perpendicular to the second plane 202. A second distance 216 between the second contact edge region 22 and the fourth plane 206 in a direction normal to the fourth plane 206 is shown and is preferably in the range of 8 to 25 mm, more preferably 15 to 20 mm. These ranges of the second distance 216 are also particularly beneficial for flat-bottom rail tracks, resulting in a stable placement of the sensor device 1. The resulting distance of the top surface 10 from the top of the head portion of the rail in this way can be set to anywhere between about 35 mm to about 55 mm.
In one embodiment, the sensor device 1 is configured for sensing wheels of a rail vehicle passing the sensor device. Such a sensor device is described in patent document NL 2023451, which is incorporated herein by reference. Noted in particular are pages 9-16 thereof, which describe a preferred embodiment. As can be seen in
A flat-bottomed rail track 2 is shown in
The rail track 2 in cross section comprises a base portion 40, a head portion 44 for receiving wheels of rail vehicles, and a neck portion 42 connecting the base portion 40 and the head portion 44. The head portion 44 broadens from a neck portion side thereof in a direction away from the base portion 40 thereby defining a base portion facing surface 54 of the head portion 44 adjacent to the neck portion 50. A first intermediate part 52 between the neck portion and the head portion 54 has a smallest radius of curvature relative to the radius of curvature of the neck portion 50.
Similar to the head portion 44, the base portion 40 broadens from a neck portion 42 side thereof in a direction away from the head portion 44, thereby defining a head portion facing surface 56 of the base portion 40. A second intermediate part 51 between the base portion 40 and the head portion 54 has a smallest radius of curvature relative to the radius of curvature of the neck portion 50. The rail track 2 has a symmetry plane 58. In
Once the device is placed, the device 1 is slid in a sliding direction at least partially along a normal direction 600 of the top side 10 of the sensor device1 in order to place the first contact edge region 20 in contact with the rail track, in particular with the base portion facing surface 54. During the sliding the second 22 and third 24 contact edge regions remain in contact with the neck portion 42 of the rail track. Then the position of the device 1 shown in
The alternative is to first place the first and second contact edge regions in contact with the rail track. The first contact edge region would then be in contact with the surface 54. Thereafter the sensor device can be slid in a direction such that the third contact edge region moves closer to the neck portion of the rail track until it finally touches the rail track.
The second and third contact edge regions are configured to be in contact with the lateral side of the rail track at the neck portion thereof, and wherein the first contact edge region is configured to be in contact with the lateral side of the rail track at the head portion thereof.
As can be seen from
In other words, the housing 9 is configured such that the first contact edge region 20 is in contact with the base portion facing surface 54 when the second 22 and third 24 edge regions are in contact with the neck portion.
By choosing the position of the first contact edge region 20 relative to the second contact edge region 22, the top surface 10 will have a certain distance 700 from the top 59 of the rail track 2, indicated with a tangent 702. In the configuration of
In addition, a distance between the third contact edge portion 824 and the second contact edge portion 822 is less than in the sensor device 1.
Herein, examples of the sensor device are shown for rail tracks having a concave neck portion. Rail tracks exist with a flat neck portion. For those types of rail, the second and third contact edge regions can be made to extend from the housing 9, and/or the side surface 32 can be made concave such that it does not interfere with the placement of the device.
The use of magnets, such as the magnet 8, for mounting the sensor device has an additional advantage in particular for sensor devices for measuring magnetic fields. The mounting magnet cause the suppression of magnetic fields induced in the rail by rail vehicles passing the rail near the device. The additional magnet(s) apply a magnetic field to the rail, due to which the device can more accurately measure the effect of the wheel onto the magnetic field measured by the magnetic field sensor. Without this magnetic field of the mounting magnet(s) such as magnet 8 applied to the rail, when a train or other typically heavy rail vehicle passes by, a magnetic field is induced by the force introduced onto the rail. This effect is known as the Villari effect or the inverse magnetostrictive effect. This effect can be described as the change of the magnetic susceptibility of a material when subjected to a mechanical stress. More generally, with the mounting magnet, the effect of the force exerted by the vehicle is at least reduced or even eliminated, since most, if not all, of the magnetic domains in the rail will substantially align with the magnetic field induced by the additional magnets.
The disclosure comprises the following clauses:
1. Sensor device configured to be placed on a lateral side of a rail track, the sensor device comprising:
2. Sensor device according to clause 1, wherein the housing is configured such that, when the sensor device is placed on the rail track, at most the first, second and third contact edge regions are in contact with the rail track.
3. Sensor device according to any one of the preceding clauses, wherein the sensor device is configured for sensing wheels of a rail vehicle passing the sensor device, wherein preferably the sensor device comprises a magnetic field sensor for sensing a magnetic field influence of the passing wheel.
4. Sensor device according to any one of the preceding clauses, wherein the first contact edge region is adjacent to the top side.
5. Sensor device according to clause 4, wherein the mounting side comprises a side portion positioned at a lateral side of the housing and connecting the second contact edge region and the third contact edge region, and a slanted portion between the top side and the side portion, wherein the first contact edge region is an edge region between the top side and the slanted portion, the second contact edge region is an edge region between the side portion and the slanted portion, and the third contact edge region is an edge region between the side portion and the base side.
6. Sensor device according to any one of the preceding clauses, wherein the rail track in cross section comprises a base portion, a head portion for receiving wheels of rail vehicles, and a neck portion connecting the base portion and the head portion,
7. Sensor device according to clause 6, wherein the head portion broadens from the neck portion in a direction away from the base portion thereby defining a base portion facing surface of the head portion adjacent to the neck portion, wherein the housing is configured such that the first contact edge region is in contact with the base portion facing surface when the second and third edge regions are in contact with the neck portion of the rail track.
8. Sensor device according to any one of the preceding clauses, wherein a first distance between the second contact edge region and the second plane in a direction normal to the second plane is in the range of 3 to 40 mm, preferably 4 to 20 mm.
9. Sensor device according to any one of the preceding clauses, wherein a fourth plane extends through the first contact edge region and is perpendicular to the second plane, wherein a second distance between the second contact edge region and the fourth plane in a direction normal to the fourth plane is in the range of 8 to 25 mm, preferably 15 to 20 mm,
10. Sensor device according to any one of the preceding clauses, wherein the first, second and third contact edge regions are positioned substantially along a curve following a cross section surface profile of the rail track, wherein preferably the rail track is a flat-bottomed rail track, wherein more preferably the rail track is a 54E1 rail profile, a 54E2 rail profile and/or manufactured according to European Standard EN 13674-1 or 13674-4,
11. Sensor device according to any one of the preceding clauses, wherein the first, second and third contact edge regions extend along the mounting side such that, when the device is placed on the rail track, the first, second and third contact edge regions extend in a longitudinal direction of the rail track.
12. Method of placing a sensor device according to any one of the preceding clauses on a lateral side of a rail track, the method comprising:
13. Method according to clause 12, wherein the sensor device is placed with the second and third contact edge regions in contact with the lateral side of the rail track; and
14. Method according to clause 12 or 13, wherein the rail track in cross section comprises a base portion, a head portion for receiving wheels of rail vehicles, and a neck portion connecting the base portion and the head portion, wherein the second and third contact edge regions are placed in contact with a surface of the neck portion of the rail track.
15. Method according to clause 14, wherein the sliding direction is towards the head portion such that after sliding the first contact edge region is placed in contact with a base portion facing surface of the head portion.
16. Assembly comprising a sensor device according to any one of clauses 1-11 and at least one rail track.
Whilst the principles of the described methods and devices have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2024146 | Nov 2019 | NL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/080260 | 10/28/2020 | WO |
