JPS6237326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION It is an object of the invention to provide a method for measuring certain geometrical features of the head of a rail of a railway track, and an apparatus for carrying out the method.

Devices for measuring rail deformations are already known which are capable of measuring defects in the longitudinal or cross-sectional profile of the rail, such as corrugation defects due to wear caused by contact with train wheels.

However, other defects in the roll surface of the rail due to wear cannot be detected by these measuring devices, especially regarding the shape of the rail head with respect to the reference or original contour and the rail on the other hand. With these measuring devices, the position of the cross-sectional contour of the track as well as the deformation of the geometrical characteristics of the cross-sectional contour of the neck, side or roll planes, such as the amount of curvature and inclination with respect to the contour of the railway track, are determined by these measuring devices. Unable to detect.

The lateral inclination of the roll surface of the rail facing inward of the track is provided in combination with the conicity of the roll surface of the wheel to ensure stability of the wheel on the track. This slope varies according to the railway network between approximately 1/20 and 1/40 in proportion.

The curvature of the rail roll surface reduces as much as possible the sliding and friction effects between the rail and the wheel due to the multiple contact areas between the roll surface and the conical roll surface of the wheel, resulting in different peripheral rotational speeds. given to obtain the best contact conditions.

The deterioration of these two features of the rail roll surface, inclination and curvature, is therefore important to investigate, i.e. it is a non-negligible fraction of the general strain increase in the characteristics of the rail roll surface of the track. contributes to speed, and therefore before the change becomes a hindrance to the good running of the train.
Consideration should be given to providing opportunities for polishing and correction.

It is an object of the invention to determine by simple means the cross-sectional profile of the head of the rail of a railway track, such as the slope, curvature or partial or total cross-sectional profile and the position of one rail with respect to the other rail. The objective is to enable the measurement of certain characteristics of.

The measuring method according to the present invention has the following features. That is, a reference baseline is defined that is perpendicular to the longitudinal direction of the track and parallel to a straight line that simultaneously touches each roll surface on the two rails. The position of at least two points on the surface of the head of the rail with respect to the reference baseline is determined. These measurements define at least one characteristic of the cross-sectional profile of the rail and head surfaces as a function of the position of the point with respect to a longitudinal line on the rail.

Another object of the present invention is to provide a device for measuring the characteristics of the cross-sectional profile of the head of a rail of a railway track, which device has the following features. That is, the measuring carriage, which is supported longitudinally and laterally on two rails of a railway track by means of a holding element, is aligned perpendicularly to the longitudinal direction of the track and parallel to a straight line simultaneously tangent to the roll plane of each of the two rails. at least two detectors defining an extending reference baseline and providing signals representative of the distance between the reference baseline and at least two longitudinal sidelines of the profile of the head of the rail; and signals generated from the detectors. An electronic processing device is provided which has a calculation unit which determines a feature of the actual cross-sectional profile of the rail as a function of its position with respect to a certain longitudinal line on the rail.

An embodiment of the measuring device of the invention is shown schematically in the accompanying drawing.

The method according to the invention continuously, i.e. during the movement of a vehicle along a railway track, for each point of a rail or at predetermined intervals along said rail as a function of its position with respect to other rails. It is contemplated to define certain features of at least the cross-sectional profile of the head of the rail. It is further contemplated to provide the deviation of these characteristics measured for a worn rail relative to a desired value or reference value for a new rail correctly positioned with respect to the other rails of the railway track.

In particular, this method makes it possible to define these features of the cross-sectional profile of the rail, which are as follows.

1. A straight line that is perpendicular to the longitudinal direction of the track and touches the roll surface of each of the two rails of the track, and a straight line that passes through two points located above the two longitudinal lines on the rail head that limit the roll surface of the rail. Its slope is represented by the angle formed by .

2. Its curvature given by the deflection exhibited by the roll surface corresponding to a given string.

3. All or part of the cross-sectional profile which is the shape of the head surface of the rail at a given point on the track as well as the relative angular position of one rail with respect to the other. This is a complex feature that includes the slope of the roll surface, its chord not only in the region of the roll surface but also at the sides and neck of the rail head, and the shape.

In order to measure these different features of the cross-sectional profile of the rail head, a line defined by a straight line running perpendicular to the longitudinal direction of the track and parallel to a line tangent to the roll surfaces of the two rails and parallel to the plane of the track is used. It is necessary to have a reference baseline. Such a reference baseline is
It can be realized by a measuring carriage that rolls on a track with rollers that have vertical and horizontal abutting parts against two rails.

a. To determine the inclination of the roll surface of the rail, the distance between two longitudinal lines of the head of the rail placed approximately at the edges of the roll surface of the rail and the reference baseline is measured.

These two values Ya and Yc are known and the slope of the roll surface of the rail is determined by the following equation.

i=(Yc-Ya)/D where D is the foot distance from the two longitudinal lines to the reference baseline, and i corresponds to the tangent of the inclination angle of the roll surface.

b To determine the deflection of the roll surface, the distance Ya and
After Yc, the distance Yb between a reference baseline and a point on the rail placed approximately midway between said two longitudinal lines that limit the roll surface of the rail is measured. In that case, the deflection is given by:

f = (Ya + Yc - 2Yb) / 2 c Finally, in order to determine the shape of all or part of the cross-sectional outline of the head of the rail and the angular position of the corresponding parts of the two rails, The distances between a plurality of points on the head surface of the rail spaced apart from a reference baseline are measured. Thus, for a given portion of the rail, a set of measurements is obtained which determines the actual contour of the roll surface of the rail head as a function of the position of one rail with respect to the other rail of the track.

In practice, the measurements obtained are carried out as follows so that they can be easily used.

a Record directly the value of the slope i of the roll surface of the rail in function of the displacement along the rail. This value i of the slope of the rail or the desired reference indication io
A signal Δi is provided which represents the deviation of the slope of the rail with respect to its desired slope, which can be compared to .DELTA.i and plotted graphically as a function of displacement along the rail.

b The value of the deflection f of the roll surface of the rail in function of the displacement along the rail is recorded directly.

A signal Δf giving a deviation with respect to the desired deflection
This value of the deflection f of the roll surface of the rail can also be compared with a desired reference deflection fo in order to obtain . This deviation can also be represented graphically as a function of displacement along the rail.

c Similarly, i.e. by comparing the relative angular position of one rail with respect to the other rail of the track with the value corresponding to the surface contour indicating the deviation of the cross-sectional contour and position of the rail head with respect to the reference contour of this head. You can proceed.

However, in order to obtain a usable graphical reproduction, the deviation of the actual contour Δpy with respect to the reference contour is determined by the deviation measured in the radial direction with respect to the pole or center placed on the rail symmetry axis, as shown in FIG. Δp
ρ or the deviation Δpr measured perpendicular to the reference contour of the head of the rail. These deviations Δpρ
Or Δpr can then be expressed graphically as a function of the angle of the arch S or with respect to the center ψ measured from the mid-plane of the rail. In that case, the theoretical contour is represented by the abscissa line and the contour deviation Δp is plotted on the ordinate for each point of measurement. This allows a readily readable graphical representation of the relative angular position of one rail with respect to the other rail of the track and of the deviation Δp with respect to the reference cross-sectional profile. In fact, it is given electronically that the measured deviation Δp placed in the plane of symmetry of the rail or on the intermediate longitudinal line of the roll surface is equal to zero. A positive deviation Δp therefore corresponds to a part of the rail that has unnecessary material, and a negative deviation corresponds to a part of the rail that does not have enough material with respect to the reference contour of this rail.

This provides an accurate, easily readable and usable graphical representation of the deviation of the cross-sectional profile of the rail with respect to its angular position as well as its shape.

Such measurements of the profile can be repeated at regular intervals along the length of the rail, and a comparison of the graphs obtained thus allows for the determination of the profile of the head of the rail as a function of the distance driven along the track. A deformed shape is obtained. This shape can be displayed, for example, in an axonometric representation of a predetermined number of graphs for successive points of the rail, or on an oscillograph by a series of perspective views.

This method of measuring the features of the cross-sectional profile of a rail can be compared to the known measuring methods of the longitudinal profile of a rail, in particular the Swiss patent application for example
It is clear that it can be combined with the method for measuring its longitudinal corrugation deformation as described in CH2165/79 or CH2164/79. It is possible to use some of the measurements made by the method of the invention in combination with other measurements made at longitudinally spaced points along the rail to determine the longitudinal deformation of the rail. .

It is also clear that measurements can be taken simultaneously on both rails of the track.

An apparatus for carrying out the method described above is shown in FIGS. 1 to 4, which comprises a measuring carriage 1 adapted to be continuously displaced along a railway track.
has. This carriage has two inner abutment flanges at both ends which rest longitudinally and laterally on the two rails 5 of the railway track.
It has two longitudinal beams 2 supporting two rotating and guiding rollers 3 and 4. The carriage can also have only one transverse beam carrying rollers that abut laterally and longitudinally on the two rails, and for maintaining said beam in a position perpendicular to the axis of the track. The means are given. An intermediate telescoping connecting cross-beam 6 is hinged at its ends on a vertical axis 9 carried by a section 7 fastened to one of the longitudinal beams 2 and a support 10 fixed to the other longitudinal beam. It has a movable part 8. This movable part 8 with a limited stroke is subjected to an axial thrust of a helical spring 11 sufficient to keep the flanges of the rollers 3, 4 in abutment against the two rails 5 during the measured displacement. It will be done. This measuring carriage has a pole 12 that allows connection to a driven track vehicle.

The measuring carriage 1 is mounted between rollers 3 and 4 and mounted laterally above each rail 5.
It has three measurement detectors 13, 14, and 15. These detectors are spaced apart by a distance d,
It covers at least a portion of the roll table of the rail above three points A, B, and C on the roll surface shown enlarged in FIG. Preferably, the longitudinal line passing through points A and C of the head of the rail is a line that approximately limits the roll surface of the rail, while the longitudinal line passing through point B is actually a line that limits the longitudinal midplane of the rail. is placed in These detectors are electronic detectors and do not come into contact with the rail and are _e.g.
The distance separating points A, B, and C on the roll surface of
Capacitive or optical means for providing an overcurrent capable of generating electrical signals representative of Ya, Yb, Yc. These detectors are formed by the intersection of the chord extensions through points A and C of the trace of the roll surface with a straight line D ₁ parallel to the plane of the railway track and forming a reference baseline defined by the measuring carriage. Its inclination i with respect to the surface of the railway track, represented by the tangent of the angle, and the deflection of the chord, arch AC, at the midpoint B, 2
It is used to determine the curvature of the roll surface of the two rails 5. This calculation is obtained using the following simple formula:

f=(Ya+Yc-2Yb)/2 and i=(Yc-Ya)/D In this case the distances Ya, Yb and Yc and the distance D=2d between the detectors 13 and 15 are used.

In addition, it is also possible to make Ya equal to zero or a constant value, that is, to make the reference baseline pass through point A. In that case, the detector 13 is replaced by a roller that contacts the rail at point A. In these conditions, only one measurement is required to determine the slope i, and only two measurements are required to determine the deflection f.

An electronic processing device for the signals provided by the detectors 13, 14, 15 is shown in FIG. 4, which amplifies and shapes the detector signals and separates the rail points A, B, C from the reference base. signal indicating the distance to
It has amplifiers 16, 17, and 18 that provide Ya, Yb, and Yc.

A first calculation unit 19 having a conversion function (Yc-Ya)/D is fed with the signals Yc and Ya and provides a signal i representing the inclination of the roll surface of the rail.

Signal i is either recorded directly in function of the length of transition along the railway track or fed to a comparator 20 which carries out a comparison of signal i against a reference value of said slope stored in memory 29. obtain. This comparator provides a signal Δi representing the deviation between the actual value of the inclination of the roll surface of the rail at a given point of this rail with respect to the reference baseline, that is to say with respect to the other rail, and the reference value.

This value Δi is obtained in a known manner as disclosed in Swiss Patent CH 588,374, and its running average value can be represented graphically as a function of the distance transported by the measuring carriage.

The electronic device furthermore has a second calculation unit 21, whose conversion function is (Ya + Yc - 2Yb)/2, which after being shaped and given a signal f representing the deflection of the roll surface, calculates the output of the three detectors. given by the signal.

This signal f is either recorded directly in function of the distance traveled along the trajectory, or is fed to a comparator 22 which determines the deflection recorded in memory 23.
Comparing this signal f to a desired value of fo provides a signal Δf representing the deflection deviation with respect to the desired reference value.

The signal Δf is then processed similarly to the signal Δi,
Taking into account the angular position of the profile of one rail with respect to the other rail, an easy-to-use graphical representation of the deflection deviation of the cross-sectional profile of the roll surface of the rail is obtained.

On the recording tape of the recorder, the actual values are recorded directly or their changes Δ in function of the transition path.
The calculated value of the deflection f is recorded in the form of a graph of f.

The recording device may be a recorder of known type with or without a coder for converting the output analog signal into a digital value.

For example, when alignment on the same plane is not possible due to widthwise obstacles or other work criteria, 3
The two detectors 13, 14, 15 may be longitudinally spaced apart. In this case, the values representing the distances Ya, Yb, Yc are determined in the form of the average value of the detected distances for a given length, so as to eliminate the influence of longitudinal defects on the measured instantaneous values. .

Of course, more than two detection points can be used to determine the amount of curvature of the roll tape, for example when different areas of the roll surface with different curvatures have to be inspected. Taking into account the symmetry of the rail, it is then advantageous to place, for example, two groups of detectors placed symmetrically at different distances on either side of a central detector placed in the plane of symmetry of the rail.

The example given for the roll surface can also be applied to the neck and side of the head of the rail, either directly or by driving the measurement detector at a given angle with respect to the reference baseline.

The detector used may be of another type, for example with a contact feeler consisting of a high-resistance stay plate hinged to the end of a movable measuring rod, or of the capacitive or optical type.

When it is desired to know the cross-sectional or cross-sectional outline of the rail head in more detail, the distance between points K...N on the surface of the rail head placed on different longitudinal lines of the head and the reference baseline. It is necessary to have multiple detectors to measure the

In these conditions, the reference baseline and the point K
...Distance to N...Distance Yk...Detector 2Xk that measures Yn
...2Xn is provided. The output signals of these detectors are connected to the reference baseline and the rail points K...N
In order to form signals Yk...Yn representing the distance between the two points, the signals are amplified and shaped by amplifiers 25k...25n. These signals Yk...Yn are such that any one of these signals may have a value Yn corresponding to the value of the measurement made on the mid-longitudinal line of the head of the rail, so as to obtain an indication relative to the surface of the rail, for example. is applied to a calculation unit 26 which subtracts it from this.

Each of these signals is then passed through a comparator 27k.
...In 27n, the reference external shape memory 28k...
...28k...28n are compared individually. These comparators provide signals Δpk...Δpn representing the deviation of the actual contour at points K...N with respect to the corresponding values of the reference contour.

Since these measurements are made during the displacement of the measuring carriage, the average value of each signal Δpk...Δpn is formed in a known manner over a given time interval. The processing is then performed to obtain an appropriate indication of the deviation of the outline.

Indeed, in the example disclosed by the measurements made, one is the axis of symmetry of the transverse section of the rail, and the other is with respect to the other rail along the orthogonal axis positioned perpendicular to the axis of the rail. The shape of the outer shape is determined as the position of one rail. However, in using these coordinates, if the actual contour is represented graphically, the sides of the rails are represented very inaccurately and uncertainly, which makes practical use of the resulting representation impossible.

These Cartesian coordinates of the points K...N of the rail are thus transformed in the ordinate perpendicular to the reference contour and in the curved abscissa or in the polar coordinates having as origin a pole placed on the axis of symmetry of the rail.

In the first case, the deviation according to FIG. 6 is represented, the reference contour is developed and represented by a horizontal line,
The deviation Δpρ is plotted on the ordinate as a function of the angle φ. The signals are processed so that the deviation Δp with respect to a central line placed in the plane of symmetry of the rail is equal to zero. A positive Δp then corresponds to an excess of material and a negative Δp corresponds to a measured rail material loss with respect to its reference contour.

In the second case, the deviation of the contour according to FIG. 7 is represented, the reference contour is again developed and represented by a horizontal line, and the deviation Δpr is plotted on the ordinate in function of the curve abscissa S of the contour. Again, the offset measured on the mid-longitudinal line of the rail is taken as the origin of the ordinate.

These two types of display provide an easy to read and accurate representation of all parts of the measured profile.

When displacing the measuring carriage along the track in this way, a series of graphical representations of the cross-sectional profile of each rail is obtained. For their practical use, we reduce the number of these consecutive graphs and
It would also be interesting to carry out such a display only at given intervals, for example every meter. In this case it is possible to record the average or instantaneous contour along this interval. Also, for example, in view of these predetermined numbers of consecutive graphs, it is possible to realize reproduction on an oscillograph.

Electronic processing of the measurement signal can be improved to obtain other indications. The important point is that in order to obtain an indication of the shape of the rail's cross-sectional profile and its position with respect to other lines of the rail, measurements are always taken with respect to a reference baseline parallel to the plane of the railway track and perpendicular to its axis. It is what is done.

It is also clear that the known determination of the longitudinal deformation of the roll surface of the rail can be combined with the measurement of the cross-sectional profile of the head of the rail. In such cases, for example, Swiss patent application CH 2165/79
Alternatively, it is also possible to replace one of the three detectors disclosed in 2164/79 with one of the detectors disclosed in this application. In this case, the signal provided by this detector is simultaneously used to determine the longitudinal deformation of the roll surface and to determine one of the features or the cross-sectional profile of the head of the rail.

By using a transverse reference baseline perpendicular to the axis of the railway track and parallel to the tangent to the roll surfaces of the two rails, a measurement made at one of these lines of the rail will reflect the characteristics of that line of the rail itself. Not only is there no dependence on the relative angular position of that line with respect to other lines of the rail.

This is one of the essential features of the invention.

[Brief explanation of the drawing]

FIG. 1 is a side view of the measuring carriage, FIG. 2 is an enlarged cross-sectional view of this measuring carriage, and FIG.
The figure is a detailed enlarged view of FIG. 2, FIG. 4 is a block diagram of the electronic processing device for measurement, and FIG.
6 and 7 are graphical representations of the cross-sectional outline of the head, and FIG. 8 is a block diagram of a modification of the electronic processing device for measurement. DESCRIPTION OF SYMBOLS 1...Measuring carriage, 2...Beam, 3, 4...Roller, 5...Rail, 6...Telescope type connecting cross beam, 11...Coil spring, 12...Pole, 13,1
4, 15...Measurement detector, 16, 17, 18...Amplifier, 19...First calculation unit, 20...Comparator, 21...Second calculation unit, 22...Comparator,
23...Memory, 24K...24n...Detector, 25k
...25n...Amplifier, 26...Calculation unit, 27k
...27n...Comparator, 28k...28n...Memory.

Claims (1)

[Scope of Claims] 1. Perpendicular to the longitudinal direction of the railway track and 2.
Determine a reference baseline parallel to the straight line that is in contact with each roll surface on the two rails at the same time,
determining a respective spacing between at least two longitudinal lines on the head of the rail and said reference base, and calculating from said spacing at least one of the actual cross-sectional contours of said head as a function of position relative to a line on the rail; A method for measuring at least one geometric feature of the cross-sectional profile of the head of at least one rail of a railway track having two parallel rails, the method comprising the steps of: 2. In the step of determining the distance, the distances Ya, Yc between two points A, C located on each of the two longitudinal lines defining the roll surface on the rail head and the reference baseline are determined.
is determined, and in the calculation step, a value (Yc−
The method according to claim 1, characterized in that the method calculates Ya)/D (D is the distance of the foot from the points A and C to the reference baseline). 3 In the step of determining the distance, determine the distance Yb between the point B on the rail located between the points A and C and the reference base, and in the calculation step, calculate the distance between the roll surface and the chord of the roll surface. 3. A method as claimed in claim 2, characterized in that the value (Ya+Yc-2Yb)/2 is calculated representing the deflection of . 4. A patent characterized in that the value of the feature represented by the calculation is compared with the value of the reference outline corresponding to the feature, and a signal having a value corresponding to the deviation of the actual outline from the reference value is generated. A method according to claim 1. 5. Method according to claim 1, characterized in that corresponding features of the actual cross-sectional contours of the heads of the two rails are determined simultaneously. 6. Measurement determined by determining a reference baseline parallel to a straight line perpendicular to the longitudinal direction of the railway track and simultaneously touching the roll surfaces of the two rails, supported in the vertical and lateral directions by the two rails of the said track. a carriage, at least two detectors generating signals corresponding to the spacing between at least two longitudinal lines on the head of the rail and said reference baseline; an electronic device having a calculation unit for determining the characteristics of the cross-sectional profile by means of signals generated by a detector; A device for measuring at least one characteristic. 7 a conversion function (Yc-
Ya)/D (Yc and Ya represent the spacing with respect to the two detectors, and D represents the horizontal spacing of the two detectors). The device described. 8 a third detector disposed intermediate said two detectors, and a conversion function (Ya+Yc −2Yb)/2
7. A device according to claim 6, characterized in that it has a second calculation unit (Yb represents the spacing with respect to the third detector). 9 The plurality of detectors each measure the position of a plurality of points on the cross-sectional outline of the rail head, and the position of the measuring point is compared with the position of the corresponding measuring point on the reference outline to determine the reference outline. 7. A device according to claim 6, comprising: said electronic device comprising a device for generating a signal ΔP representative of said deflection at each considered point. 10. The apparatus of claim 6, comprising said detector for each rail of the track as well as said electronic device for each rail of the track. 11. The apparatus of claim 6, wherein one of the detectors is part of a device for measuring the longitudinal deflection of the roll surface of a rail.