RU2578897C1 - Method for assessing theft of rail section - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: invention relates to methods of longitudinal movement (creep) of sections of jointless rail track. Method for assessing the rail stalk creep consists in the fact that on each reference sleeper and rail stalk, on the non-working side of the rail and at a known distance from each other, there are installed beacons - ferromagnetic elements so as to provide reliable detection of signals from them with the help of a magnetic flaw detector. Invention presupposes measurement of a time mismatch between beacons and determination of the distance between them. Rail stalk creep is evaluated by comparing the current distance between beacons with results of previous measurements taking into account the allowable value limit, as well as by comparing rail creepings on nearby reference sleepers.

EFFECT: higher accuracy and reliability of evaluation of rail stalk creep.

1 cl, 3 dwg

Description

The invention relates to the field of use of control and measuring devices for checking the condition of a railway track, in particular, to methods for measuring and controlling the longitudinal movement (hijacking) of sections of rail lashes of a jointless railway line.

At present, along the great length of the main tracks of the Russian railways, a jointless path is used, where the rails are connected to each other in long lashes by welding. One of the most pressing issues for a continuous joint is its operation during a period of significant changes in air temperature, which lead to an increase in longitudinal stresses in rail lashes. Thermal contraction in winter can lead to rupture of the rail lash, mainly in the area of welded or bolted joints. And heating in the warm period leads to stretching of the rail lash, bending (hijacking) of rail lashes, i.e. to a change in their geometry, leading to the descent of the rolling stock from the rails.

There is a known [1] method for monitoring the theft of rail lashes according to marks applied with paint on the feather of the sole of the rail and on the lining of the lighthouse (fixed) sleepers.

The disadvantage of this method is the need for visual monitoring of the shift labels directly by a person (employee distance travel). Visual control performed by man has a very low productivity, can be performed only during daylight hours, in the absence of snow cover, and is associated with danger for maintenance personnel during heavy use of the railway section.

Known methods for measuring stresses in rail lashes using various sensors: strain gauge [2], magnetic [3] and [4], Barkhausen noise [5], as well as ultrasonic methods [6].

The disadvantage of all these methods is that the assessment of the tension of the rail does not allow to evaluate the real theft of the rail and to assess the degree of its danger.

A known method [7], in which the reading of marks on the rail and the detection of lighthouse sleepers is carried out by an automated system with optical sensors that detect marks on the rail, as well as lighthouse sleepers.

The limitations of this method consists in the impossibility of use in snow cover, contamination of marks and lighthouses, etc.

Closest to the claimed invention is [8] a method for assessing the theft of a rail lash, which consists in the fact that, moving a magnetic flaw detector, probe the rail lash and receive response signals, detect signals from the first marks connected to the rail lash and second marks connected to beacon sleepers, measure their temporal mismatch and determine the distance between them using a flaw detector displacement sensor, evaluate the theft of the rail lash by comparing the current distance between the marks with the result Ami previous measurements and with the boundary of its permissible value, save the results. The weld joints of the rails are used as the first marks, and signals from the rail linings, which can be detected by a magnetic flaw detector, are used as the second marks.

The disadvantage of this method [8] is the low accuracy of the measurements. It is known that the usual distance between lighthouse sleepers is about 100 meters and to facilitate detection they are placed near picket posts. The distance between the joints of the weld path is usually 25 meters. Thus, the distance between the welded joint and the lighthouse can be up to 25 meters. Dangerous theft of rail lashes (displacements of the rail mark relative to the lighthouse sleepers) in the linear dimension are usually considered displacements of 1 cm or more. Thus, to determine such a bias by the method of [8], measurements of all parameters with an accuracy of no worse than 0.04% are required. Obviously, such accuracy is unattainable.

The problem solved by the claimed method is to increase the accuracy and reliability of the assessment of the theft of the rail lash.

To solve this problem, in a method for assessing the theft of a rail lash, which consists in the fact that, by moving a magnetic flaw detector, a rail lash is probed and receive response signals, signals from the first marks connected to the rail lash are detected, and second marks connected to the beacon sleepers are measured their temporary mismatch and determine the distance between them using a flaw detector displacement sensor, evaluate the theft of the rail lash by comparing the current distance between the marks with the results of previous measurements and by the boundary of its permissible value, the obtained results are saved, on the non-working side of the rail, on each beacon sleepers, a ferromagnetic element is installed, which is used as a second mark, and a ferromagnetic element is used on the rail lash at a known distance from the second mark and near it as the first mark, these ferromagnetic elements are set so as to ensure reliable detection of signals from the marks by a magnetic flaw detector, the assessment of the theft of the rail lash is carried out with assuring initial distance between the first and second marks, and comparing the nearby rail hijacking majachnyh sleepers.

Significant differences of the proposed method compared with the prototype are the following.

Installation of marks on the non-working side of the rail provides their protection from the effects of rolling stock.

The prototype does not use special tags.

The installation of ferromagnetic elements on each lighthouse sleepers and on the rail whip at a known distance allows you to get the minimum distance between the marks, which can be measured with high accuracy.

The prototype uses signals from welded joints and rail linings, spaced tens of meters away, which does not allow to measure the mismatch with the required accuracy.

Setting the labels in such a way as to ensure their reliable detection of signals from the labels by a magnetic flaw detector has a designated purpose, but does not require large material costs.

The prototype uses existing tags (welded joints and rail linings), but their detection is not always guaranteed.

An assessment of the hijacking of a rail lash taking into account the initial distance between the first and second marks allows one to take into account the methodological error of the initial marking and thereby increase the accuracy of measurements.

In the prototype, taking into account the initial mismatch of the welded joints and rail linings is almost impossible for reasons of accuracy.

Comparison of rail theft on nearby lighthouse sleepers, i.e. on the rail track, allows you to integrally evaluate the degree of theft. Obviously, its displacement does not occur at one point, but develops gradually: from small to large thefts. The approximation of several values of theft allows, for example, to determine the point of greatest theft of the rail lash.

In the prototype, hijacking is considered as a point hijack, i.e. only within the lighthouse sleepers.

The inventive method is illustrated by the following graphic materials.

FIG. 1 Appearance of the first and second marks, where:

1. The first label;

2. The second label;

3. Bracket.

FIG. 2 Signals from tags in a magnetic flaw detector.

FIG. 3 Rail track, where:

4. Rail;

5. Lighthouse sleepers;

6. Excitation coils of a magnetic flaw detector;

7. Magnetic flux;

8. Sensor magnetic flaw detector;

9. Signals of a magnetic flaw detector.

Consider the possibility of implementing the proposed method.

On the track set the first 1 and second 2 marks.

The design and arrangement of the first ferromagnetic mark on the rail should have the following features:

- do not interfere with the passage of the wheels of any mobile unit along the rail track;

- clearly fixed by the sensor of the magnetic channel of the flaw detector car, and the response form from the mark must differ from the response form from internal and surface defects in the monitored rails;

- to provide the possibility of a certain separation in time (in space) of the signals from the bracket of the lighthouse sleepers and tags, so that the maximum shift of the rail lash does not lead to the merger of the considered signals;

- not to reduce the strength characteristics of the rail;

- the rail mount must be resistant to vibration, to changes in operating conditions in a wide temperature range (temperature amplitude difference up to 110 degrees), to the effects of petroleum products and other products of the transportation process.

One possible option, FIG. 1, execution 1 of the first mark is a strip of ferromagnetic material (for example, steel tape) with a width of 5, a thickness of 4 and a length of 30 mm, glued to a non-working edge of the rail head (the outer side of the rail gauge) at a distance of 100 mm from the beacon sleepers. The mark can be glued to the rail head, for example, with weather-resistant Permatex® Black Super Weatherstrip Adhesive adhesive and so that the top edge of the tape does not extend onto the rolling surface of the rail head.

Sleepers, as indicated in [8], can be detected by a magnetic flaw detector. However, the lining of the lighthouse sleepers has features: a sliding pad and a "soft" mount. These features reduce the amplitude of the reflected magnetic signals and make it, at best, little distinguishable from other sleepers. To solve this problem, it is necessary to equip the lighthouse sleepers with additional means ensuring its reliable detection by a magnetic flaw detector. As such a means, FIG. 1, a bracket 3 may be used, mounted on a beacon sleeper, on which a second ferromagnetic mark 2 is mounted.

The design of the bracket 3 mounted on the lighthouse sleepers must meet the following requirements:

- to have sufficient rigidity and a fixed position relative to the lighthouse sleepers so that, due to the flexibility of the bracket, it does not introduce an additional error in the measured value;

- the level of the upper part of the bracket should be close to the rolling surface of the rail head;

- the upper part of the bracket with a mark 2 must have a configuration and mass that provide a clear response of the magnetic channel of the flaw detector car, and the response form must differ from the response form from internal and surface defects in the rails controlled by the flaw detector car;

- the bracket should be located on the side of the idle side of the rail head (on the outside of the track) so as not to impede the passage of the flanges of the wheels of the rolling stock;

- the bracket must have a configuration that does not fall into the area of the working elements of the snowplows and other track equipment, periodically performing maintenance of the railway track;

- should provide for the possibility of installing (securing) the bracket on the lighthouse sleepers without changing the design of rail fastenings and the sleepers themselves;

- have a maximum service life comparable to the service life of rail fasteners;

- have a minimum cost for mass production (only for the double-track section Moscow - St. Petersburg will need about 12,500 brackets);

- not require time-consuming additional operations in the maintenance and maintenance of the rail track.

There may be several design options for the brackets that satisfy the above requirements. In addition, the general view of the bracket may differ depending on the types of rail fastenings used on a particular track section. A possible embodiment of the first and second marks is shown in FIG. one.

Labeling should be done when the track is not stressed. During installation, during primary and subsequent measurements, the distances between the first and second marks are measured and stored in the database (passport) of the rail track. In this case, the measurement conditions, in particular temperature, as the main source of rail stresses can be taken into account.

When monitoring the condition of the rail track, a movable flaw detector means, FIG. 3 (a flaw detector car, a motor car, etc.), with a magnetic flaw detector, is moved along the rail 4. The rail is probed with excitation coils 6 of a magnetic flaw detector, which create a magnetic flux 7. The magnetic flaw detector 8 receives response signals 9, which, through an amplifier, are analogous -Digital converter enter the computer (the last elements are obvious and not shown with the aim of simplification). Signals are detected; FIG. 2, from the first and second marks and the temporary mismatch dx between them, and the linear distance lx between the first and second marks is determined by the displacement sensor (odometer or speed meter).

Estimate the distance obtained (hijacking a rail lash) by:

1. Comparison of lx with the allowable hijacking (1 mm);

2. With the mismatch obtained in previous measurements (the dynamics of the development of the process is analyzed);

3. Compare the theft of the rail on the nearby lighthouse sleepers.

The tasks of detecting signals from tags and estimating the amount of hijacking and estimating the degree of hijacking are carried out by a computer using obvious algorithms.

Thus, the inventive method can be implemented, requires relatively small material costs - installation of labels, uses the existing technical means - a magnetic flaw detector and allows with high accuracy and reliability to assess the degree of theft of the rail lash.

Information sources

1. Instructions for the installation, installation, maintenance and repair of the jointless path. Section 4.2. Approved by order of Russian Railways dated December 29, 2012 No. 2788 p.

2. Patent CN 203032699.

3. Patent US 2014145710.

4. Patent RU 2454344.

5. Patent RU 2521114.

6. Patent US 2014123761.

7. Patent RU 2174082.

8. Patent RU 2492088.

Claims (1)

A method for assessing the theft of a rail lash, which consists in the fact that, moving a magnetic flaw detector, probe the rail lash and receive response signals, detect signals from the first marks connected to the rail lash, and second marks connected to the lighthouse, measure their temporal mismatch and determine the distance between them using a flaw detector displacement sensor, the theft of the rail lash is estimated by comparing the current distance between the marks with the results of previous measurements and with the border of its allowable distance beginnings, save the results, characterized in that on the non-working side of the rail, on each beacon sleepers, a ferromagnetic element is installed, which is used as the second mark, and a ferromagnetic element is installed on the rail lash at a known distance from the second mark and near it used as the first mark, these ferromagnetic elements are set so as to ensure reliable detection of signals from the marks by a magnetic flaw detector, the assessment of the theft of the rail lash is carried out taking into account the initial distance between the first and second marks, as well as comparing the theft of the rail on nearby lighthouse sleepers.

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