A device for detecting railway sleepers.

Abstract

An apparatus for detecting sleepers on a track is described, which comprises a sleeper detection sensor (11), which is arranged on a track construction machine, possibly on a track inspection car assigned to the track construction machine, for inspecting and determining the position of the sleepers (5, 19) on the track. In order to be able to advantageously determine the position of the sleepers, it is proposed that the sleeper detection sensor (11) comprises a magnet generating a magnetic field (14, 15) in a magnetic circuit with at least one air gap between the sleeper detection sensor (11) and the track, and a Hall sensor (13) arranged in the magnetic circuit, wherein a Hall voltage (U) of the Hall sensor (13), which varies in the longitudinal direction (A, s) of the track, is used to determine the position of the sleepers (5, 19) on the track.

Description

Technical Field

[0001] The present invention relates to a device for detecting rail joints, comprising a joint detection sensor, which is arranged on a track construction machine, and in some cases on a track inspection vehicle assigned to the track construction machine, for measuring and identifying the position of the joint in the track.

Background Art

[0002] This type of joint detection sensor is used particularly for measuring and identifying the position of the metal fastening means that couples the rail to the joint, whereby the position of the joint can also be clearly determined.

[0003] A tamping machine is a machine for rectifying a track. For this purpose, a detection system is used to measure the actual position of the track height, the actual position of the track direction, and the actual position of the track cant during operation and compare them with a predetermined target value. By means of a track lifting and rectifying unit, the track is lifted until the difference between the predetermined target position and the actual position becomes zero and aligned laterally, and at this position, it is fixed by tamping the ballast under the joint using a tamping unit. In this case, the lifting and rectifying of the track are performed by proportional control or servo control via a suitable hydraulic lifting cylinder and rectifying cylinder. The tamping tool of this type of track construction machine must penetrate precisely into the intermediate area between the joints in order to prevent damage and breakage of the joints. Therefore, great attention must be paid to the accurate positioning of the tamping machine with the tool. Automatic positioning and forward travel of the track construction machine are possible when the joints are recognizable and not covered by the ballast layer.

[0004] In addition to maintenance work, compaction machines are also used for compacting the track in new positions after ballast sieving or track renewal. These operations are characterized by multiple compaction movements. These compaction movements are characterized by the fact that ballast is laid on the track up to the upper edge of the rails, and the compaction machine performs a large lift. The position of the sleepers is only roughly perceived by the operator by the ballast undulations that are clearly formed during the lift. In this case, the problem is that the compaction machine operator can only perform forward movement of the machine and positioning of the compaction tool in the intermediate range based on sense and experience. In this case, automatic forward movement is practically excluded. If the compaction tool is not positioned correctly, the tool will collide with the sleeper, damaging it. In addition, there is a disadvantage that the machine's performance is significantly negatively affected.

[0005] For example, the positions of rails, sleepers, and rail fasteners can be detected by various optical systems, such as laser scanners or video cameras. This enables the automatic and precise positioning of tamping tools and the forward movement of tamping machines. However, known optical methods are not useful for tracks where ballast has been laid up to the upper edge of the rails.

[0006] On tracks where ballast is laid up to the top edge of the rails, a problem arises when mechanical operators fail to recognize obstacles in the intermediate area, such as points, point mechanisms, and point closing devices, which are often present at turnouts, and these are damaged by the compaction unit during push-in operations. Optical measurement methods are not useful in this situation either.

[0007] Conventional inductive and capacitive analog sensors have a maximum detection distance of approximately 30 mm. However, a much larger gap exists between the upper edge of the rail and the height of the rail fastening means to be detected, and therefore, this type of sensor has not been effectively used until now. For example, inductive sensors have the problem of having to be set low and therefore move through the ballast. Furthermore, there is the difficulty that fastening means have varying heights depending on the type, which is equally problematic in light of short measurement intervals. In practice, there are many different types of rail fastening means. A characteristic of rail fastening means is bolt fastening, and the fastening means are made of at least mainly steel (ferromagnetic material). These fastening means are located very close to the rail, have a low magnetic mass, and are partially below the upper edge of the rail, which cannot be reliably detected by known inductive or capacitive sensors. In principle, if the sensor is lowered close enough to the fastening means for measurement, it can detect the fastening means. However, if ballast is laid up to the upper edge of the rail, such a solution is virtually impossible. [Overview of the project] [Problems that the invention aims to solve]

[0008] Therefore, the fundamental problem of the present invention is to find a detection device and unit that avoids the aforementioned drawbacks and is guided with a large gap (above the ballast) relative to the rail fastening means, even when the ballast is fully loaded, so as to clearly detect the rail fastening means. [Means for solving the problem]

[0009] The present invention solves the given problem by having a sleeper detection sensor comprising a magnet that generates a magnetic field in a magnetic circuit having at least one air gap between the sleeper detection sensor and the track, and a Hall sensor disposed in the magnetic circuit, wherein the Hall voltage of the Hall sensor, which varies in the longitudinal direction of the track, is used to determine the position of the sleeper on the track. Advantageous developments of the present invention are expressed in the dependent claims.

[0010] A magnetic field is generated within the magnetic circuit via electromagnets and permanent magnets. This magnetic field is measured by a Hall sensor through which an electric current flows. The Hall voltage of the Hall sensor increases as magnetic resistance decreases due to the presence of rail fastenings. This increase in voltage is used to pinpoint the location of rail fastenings and, consequently, sleepers along the longitudinal direction of the track, and to control the automatic forward movement of track construction machinery. The air gap, and consequently magnetic resistance, primarily changes depending on the presence or absence of rail fastenings or, in some cases, other mechanical obstacles such as switches. This is especially true between two sleepers. The progression of the Hall voltage over the length of the track, i.e., the position of the sleeper detection sensor on the track at any given time, is used to pinpoint the location of rail fastenings and, consequently, sleepers along the longitudinal direction of the track.

[0011] The magnetic circuit is closed between two sleepers via a rail. When the rail connection point enters this magnetic region, the magnetic resistance decreases, which increases the magnetic field. Before positioning the compaction unit, the rail connection points are inspected at several sleepers, and consequently, the changes in the magnetic field and the position of the sleepers are measured, allowing the signals to be evaluated in advance and the center position to be determined.

[0012] The Lorentz force, which is related to vectors, is effective for magnetic fields:

number

[0013] A Hall effect sensor operating with a known current I measures the magnetic field component By generated perpendicular to the surface of the Hall effect sensor. An electric field Ex is generated. A voltage U can be measured on the side in proportion to the electric field Ex. A sleeper detection sensor is mounted on a support vehicle and guided at a constant height above the rail and rail fastenings. The distance traveled and the Hall voltage are continuously measured. The signal is evaluated. For this purpose, boundary values ​​are successively determined starting from the difference between the base level and peak value of the signal. From the average value of the signal at these boundary values, the average position of the rail fastenings, and thus the position of the sleepers, is obtained. The measured interval ai for each sleeper is used for forward travel control and positioning of the compaction tool.

[0014] An advantage of this embodiment of the present invention is the measurement through the ballast layer and the precise positioning of the compaction tool that can be achieved thereby. This allows the compaction machine to be operated at high speed in automatic forward movement mode. The unit can also detect obstacles made of ferromagnetic material, such as drive mechanisms for switches in the intermediate zone, using multiple sleeper detection sensors arranged side by side on the trolley. [Brief explanation of the drawing]

[0015] The drawings schematically illustrate the scope of the present invention. [Figure 1] The sleeper is shown in a partial cross-sectional view, along with the rail and the W-shaped fastening section. [Figure 2] The sleeper is shown in a partial cross-sectional view, along with the rail and the K-type fastening section. [Figure 3] The structure of the railroad tie detection sensor, along with the magnetic field, is schematically shown. [Figure 4] This shows the fundamental structure of a Hall effect sensor. [Figure 5] The measurement process and the voltage signal generated by the Hall sensor are shown in general terms. [Modes for carrying out the invention]

[0016] Figure 1 shows a cross-sectional view of a rail 1 bolted onto sleepers 5 at a gradient of 1:40. Sleeper bolts 2, tightening clamps 3, angle guide plates 4, and pads 6 are shown. The tightening clamps 3, sleepers 5, and sleeper bolts 2 are made of steel and therefore affect the magnetic flux changes as the sleeper detection sensor moves along the rail 1. This allows for clear detection of these positions or longitudinal positions in the longitudinal direction of the track.

[0017] Figure 2 shows a different type of rail fastening, a so-called K-type fastening (clamp plate). On the sleeper 5, the rail 1 is bolted with a gradient of 1:40. A T-bolt 7 with a fastening nut, a clamp plate 8, a sleeper bolt 9, a ribbed plate 10, and an elastic pad 6 are shown. The T-bolt 7, ribbed plate 10, and clamp plate 8 are made of steel and reduce magnetic resistance when the sleeper detection sensor moves over the K-type fastening.

[0018] Figure 3 schematically shows the measurement structure of the sleeper detection sensor 11 mentioned herein. The sleeper detection sensor 11 is located on track construction machinery (not shown), and possibly on a track inspection vehicle assigned to the track construction machinery, to measure and identify the positions of sleepers 5, 19 on the track. The sleeper detection sensor 11 includes an electromagnet 12 that generates a magnetic field in a magnetic circuit having at least one air gap between the sleeper detection sensor 11 and the track, and a Hall sensor 13 located within the magnetic circuit. In this case, the Hall sensor 13 is located in this air gap between the sleeper detection sensor 11 and the track. The Hall voltage U, which changes as the sleeper detection sensor 11 moves in the longitudinal direction A, s of the track, i.e., along the track, is used to identify the positions of sleepers 5, 19 on the track.

[0019] The rocking bolt detection sensor 11 is equipped with an electromagnet 12. Magnetic fields 14 and 15 introduced into the rail head are generated through the electric coil of the electromagnet 12 and the magnetic core 11, particularly the soft iron core of the rocking bolt detection sensor 11. The soft iron core of the rocking bolt detection sensor 11 is formed in a substantially U shape. The magnetic core 11 is guided in the same longitudinal direction with a slight interval on the rail head or slides directly on the rail head with one leg of the soft iron core. It is also possible to introduce a magnetic field into the rail head through the wheel. When there is no rail fastening part, the magnetic circuit is closed at the other end of the magnetic core 11, that is, directly toward the rail head of the rail 1 through the other leg of the soft iron core. The end of the other leg of the magnetic core is guided on the rail fastening part that generally exists in some cases. In this embodiment, the Hall sensor 13 is supported on the contact surface with respect to the gap. Thereby, the Hall sensor 13 is arranged in the magnetic circuit.

[0020] In the region of the rocking bolt fastening part, the magnetic field changes toward the end of the magnetic core where the Hall sensor 13 is equipped through the additional coupling of the magnetic field 14 via the rail fastening part, particularly the rocking bolt 2 or the T-bolt 7. The magnetic resistance decreases, the magnetic field becomes stronger, and the measured Hall voltage U increases. The magnetic core 11 may be formed from a plurality of layers of thin plates, particularly transformer plates insulated from each other, for the reason of improving magnetization.

[0021] FIG. 4 schematically shows a Hall effect sensor 16 through which the magnetic field By flows. A current I flows through the Hall effect sensor, and the current I can be tapped through a contact that generates a voltage U proportional to the magnetic field By in a direction transverse to the current I in the Hall effect sensor. Regarding the generated Hall voltage

Equation

[0022] As shown by the relational expression, the generated voltage U is directly proportional to the current I, the material-specific Hall constant RH, and the magnetic field BY. As the thickness d of the Hall layer increases, the voltage U decreases.

[0023] Figure 5 schematically illustrates the operation. The sleeper detection sensor 11 is guided at a constant height along the rail 18 in direction A. The rail 18 is coupled to sleepers 19 via fastening means 17 at sleeper spacing ai. Furthermore, the progression of the Hall voltage U measured over the track length s is shown. When the fastening means 17 is absent, a voltage level 22 is measured. In the region of the metal rail fastening means 17, the Hall voltage U increases to 21. Here, the position of the fastening means 17 and the sleepers 19 together with the fastening means 17 can be identified. From the difference between the voltage peak 21 and the base level 22, a boundary value 20 between both values ​​can be continuously determined. Voltage The average value of the intersection points of peak 21 and this boundary value 20 gives the position of the fastening means 17, and consequently the position of the sleeper 19. This application relates to the invention described in the claims, but also includes the following other embodiments. 1. A device for detecting railway sleepers, In a device equipped with a sleeper detection sensor (11), the sleeper detection sensor (11) is positioned on a track construction machine, or in some cases on a track inspection vehicle assigned to the track construction machine, in order to inspect and identify the positions of sleepers (5, 19) on the track, The device is characterized in that the sleeper detection sensor (11) comprises a magnet that generates a magnetic field (14, 15) in a magnetic circuit having at least one air gap between the sleeper detection sensor (11) and the track, and a Hall sensor (13) disposed in the magnetic circuit, and the Hall voltage (U) of the Hall sensor (13) that changes in the longitudinal direction (A, s) of the track is used to determine the position of the sleepers (5, 19) in the track. 2. The apparatus according to item 1, characterized in that the magnet is an electromagnet (12) and / or a permanent magnet. 3. The apparatus of the second above, characterized in that the current coil of the electromagnet (12) is connected to a DC power supply and generates a DC magnetic field (By) in the magnetic circuit. 4. The device described in 2 above, characterized in that the current coil of the electromagnet (12) is connected to an AC power source and generates an AC magnetic field (By) in the magnetic circuit. 5. One of the devices described in 1 to 4 above, characterized in that a plurality of sleeper detection sensors (11) are arranged in a line in the direction lateral to the track in order to detect metal parts between sleepers (5, 19). 6. One of the devices described in 1 to 5 above, characterized in that at least one sleeper detection sensor (11) is displaceable laterally along the track by a moving device assigned to the track construction machine and / or the track inspection vehicle, for the purpose of searching for metal parts in the track. 7. The device, one of the above 1 to 6, is characterized in that at least one sleeper detection sensor (11) is positioned on the track construction machine and / or the track inspection vehicle so as to be height adjustable relative to the track. 8. The device, one of the above 1 to 7, is characterized in that the Hall sensor (13) is arranged in the gap. 9. A device, any one of the above 1 to 7, characterized in that the control device continuously determines a boundary value (20) between the voltage peak (21) and the base level (22) of the Hall voltage (U) over the length of the track, and identifies the position of the sleepers (5, 19) in the track from the average value of the intersections of each voltage peak (U) and the boundary value (20).

Claims

1. A device for detecting railway sleepers, In a device comprising a sleeper detection sensor (11), the sleeper detection sensor (11) is located on a track construction machine or on a track inspection vehicle assigned to a track construction machine in order to inspect and identify the position of sleepers (5, 19) on the track, The rail (1) is fastened to the sleepers (5, 19) by steel metal parts. The sleeper detection sensor (11) includes a magnet that generates a magnetic field (14, 15) in a magnetic circuit having at least one air gap between the sleeper detection sensor (11) and the track, and a Hall sensor (13) disposed in the air gap within the magnetic circuit. The device is characterized in that, in the presence of sleepers (5, 19), a magnetic field (14) is generated by the magnet, passing through the sleeper detection sensor (11), the Hall sensor (13), the metal component, and the rail (1) in the presence of sleepers (5, 19), and in the absence of sleepers (5, 19), a magnetic field (15) is generated passing through the sleeper detection sensor (11), the Hall sensor (13), and the rail (1) in the absence of sleepers (5, 19). Between these two magnetic fields (14, 15), the Hall voltage (U) changes, and by measuring the Hall voltage (U) in the longitudinal direction of the track (A, s) using the Hall sensor (13), the change in the Hall voltage (U) is detected, thereby identifying the position of the metal component and, consequently, the sleepers (5, 19) on the track.

2. The apparatus according to claim 1, characterized in that the magnet is an electromagnet (12) or a permanent magnet.

3. The apparatus according to claim 1, characterized in that the magnet is an electromagnet (12), and the current coil of the electromagnet (12) is connected to a DC power supply to generate a DC magnetic field (By) in the magnetic circuit.

4. The apparatus according to claim 1, characterized in that the magnet is an electromagnet (12), and the current coil of the electromagnet (12) is connected to an AC power source to generate an AC magnetic field (By) in the magnetic circuit.

5. The apparatus according to claim 1, characterized in that a plurality of sleeper detection sensors (11) are arranged in a row in order to detect metal parts between sleepers (5, 19).

6. The apparatus according to claim 1, characterized in that at least one sleeper detection sensor (11) is displaceable laterally along the track by a moving device assigned to the track construction machine or the track inspection vehicle, for the purpose of searching for metal parts in the track.

7. The apparatus according to claim 1, characterized in that at least one sleeper detection sensor (11) is positioned on the track construction machine or the track inspection vehicle so as to be height adjustable relative to the track.

8. The apparatus according to claim 1, characterized in that the control device continuously determines a boundary value (20) between the voltage peak (21) and the base level (22) of the Hall voltage (U) over the length of the track, and identifies the position of the sleepers (5, 19) in the track from the average value of the intersections of each voltage peak (U) and the boundary value (20).

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