EP1301663B1 - Method for re-profiling at least the running surface of a rail - Google Patents

Abstract

The invention relates to a method for re-profiling the running surface of a rail, preferably the convex portion of the rail head cross-profile of a rail, especially a railway rail, by peripheral milling. The aim of the invention is to obtain a profile that meets the requirements and has few corrugations. To this end, for producing the profile in a single peripheral grinding step, more than five, preferably nine milling tracks are produced that are oriented in parallel to the longitudinal direction of the rail. Optionally, the running surface, preferably the convex portion of the rail head cross-profile including the running surface is ground afterwards.

Description

The invention relates to a method for reprofiling at least the travel mirror of a rail, preferably of the driving mirror having convex part of the rail head cross-sectional profile of a rail, in particular a railroad track, by circumferential milling.

The grinding of rails for reprofiling is known from several documents in different embodiments.

So describes DE 44 37 585 C a method and an apparatus for machining the running surface of rails by peripheral grinding, wherein a rotating abrasive body along the rails is movable and pressed against the running surface and the axis of rotation encloses an acute angle with the rail longitudinal direction. The grinding wheel is freely rotatable and is ground by its friction-driven rolling on the running surface of the rail.

EP 0 843 043 A1 discloses a device for circumferential grinding of laid rails, wherein two independently adjustable and arranged on both sides of the longitudinal median plane of the rail grinding wheels are mounted in a special frame. The axes of rotation of the grinding wheels can be simultaneously pivoted about a reference line parallel to the rail direction and about a vertical, perpendicular to the rail direction reference line.

Finally shows US 4,583,327 A a rail profile grinding apparatus comprising a group of grinding wheels for circumferentially grinding with horizontally mounted grinding wheel axes and a group of grinding wheels for face grinding with vertically mounted grinding wheel axes, whereby the advantages of the respective methods can be combined and the efficiency of the grinding process is improved. The grinding wheel axes are designed to be adjustable and pivotable on the rail track.

It is off GB 2 121 710 A further known to reprofile worn rails by peripheral milling, ie to provide a new profile. For this one has the rail head machined by circumferential milling. In order to get a fairer grip on the costs of a milling cutter, it is known to provide the milling cutter with inserts which are mounted on holders, which in turn are inserted in recesses of the cutter body. In this case, the turning plates lying in one plane of the circumferential milling cutter each generate a milling track aligned in the longitudinal direction of the rail. With peripheral cutters of this type, however, it is limited in terms of the number of inserts to be mounted, u.zw. for reasons of space. It was therefore only possible to provide by circumferential milling a small number of adjacent tracks in the longitudinal direction of the rail, which are applied by the inserts on the rail head. This results in a large waviness, and it was necessary to then subject the rail head to the milling a finishing process. For this purpose, it is known to provide a peripheral cutter with a plurality of the entire desired profile having knives. The large number of knives is required in order to ensure only slight depth differences in the longitudinal direction of the rail. The disadvantage here is that the depressions and tips, which were generated by this sizing, extend over the entire machined cross-section. This causes noise and vibrations when driving over and causes a reduction in the service life.

The invention aims to avoid these disadvantages and difficulties and has as its object to provide a method of the type described above, with the one single operation a the rules of the railway or railway companies corresponding low ripple both in the longitudinal direction of the rails and in the cross-sectional profile can be achieved.

This object is achieved in that for the production of the desired profile by a single peripheral milling by means of a device more than five, preferably nine, lying in the longitudinal direction of the rail adjacent tracks and by means of the same device below a grinding at least the driving mirror, preferably the the driving mirror having convex part of the rail head cross-sectional profile, is performed.

Preferred variants are indicated in the subclaims.

To achieve higher requirements, such as higher speeds, subordinate a grinding process is performed, that to reduce or equalize the running in the longitudinal direction of the tracks ripple and optionally for smoothing or equalization of the polygon, the milled rail and immediately after milling takes place in the same run, the axis of the grinding wheel with a plane perpendicular to the longitudinal direction of the rail preferably includes a plane deviating from 0 ° angle. For this grinding preferred variants are described in the subclaims 6 to 24.

The invention is explained in more detail with reference to the drawing of two embodiments, wherein Fig. 1 a side view of an apparatus for performing the method according to the invention and Fig. 2 a schematic plan view in the direction of arrow II of Fig. 1 illustrate. Fig. 3 shows a variant of the device for Implementation of the method according to the invention. Fig. 4 shows the cross section through a railroad track in different states of the rail. Fig. 5 shows the engagement of the grinding wheel according to the inventive method on a railway rail, which is illustrated in cross section.

A Schienenprofifräser is in the Fig. 6 to 8 shown, where Fig. 6 a partial section through the cutter in the assembled state, Fig. 7 the items of the cutter in exploded view and Fig. 8 a side view of a disc of the cutter in the direction of arrow VIII of the Fig. 7 illustrate.

In Fig. 4 the cross section of a rail 1 is illustrated in different states. The rail head 3 which is seated on the rail web 2 has a convex cross-sectional part 5 which has the driving mirror 4, on which the running wheel of a rail vehicle runs, and which is illustrated by the line A when new. By wearing this convex part 5 of the cross section of the rail head 3 receives the illustrated by the line B shape. Once the rail 1 has this state or even earlier for high-speed rails earlier, a reworking of the rail 1, so that the convex part 5 of the rail head 3, but at least the driving mirror 4, in turn, the original state, ie the original cross-sectional shape - illustrated by the line C - reached as close as possible. Depending on the requirements of a railway operator or a railway company or a supraregional standard, such as cen DRAFT pr EN 13674-1, certain tolerances of the order of 1 to 3 tenths of a millimeter must be observed. It is essential here that the running edge 6 of the rail 1 and the driving mirror 4 are reworked.

How out Fig. 4 can be seen, must - depending on the wear of the rail - relatively much material to be removed, which in turn, in order to impede the rail traffic as little as possible, is carried out as quickly and inexpensively laid rails.

The Fig. 1 and 2 show a device according to the invention, which is arranged stationary and at which the rail to be processed 1 is moved past. Fig. 3 represents a device according to the invention, which is installed in a mobile device, such as a locomotive, so that with this device already laid rails can be edited. In this case, the device according to the invention is duplicated, so that both the left and the right rail can be finished with a crossing. The mutually equal parts and facilities of the stationary device and the mobile device are provided with the same reference numerals.

7 with a milling unit is designated, the rail profile cutter 8 is formed as a peripheral cutter and described below in more detail. This cutter 8 is driven by a drive motor 9 and a gear 10, wherein the direction of rotation is selected so that the rail 1 is processed in the same milling. Immediately adjacent to the milling unit 7, a grinding unit 11 is provided, the grinding wheel 12 is driven by means of a drive 13, u.zw. preferably also in the direction of rotation as the cutter 8, so that a constant velocity grinding on the rail 1 is performed. The grinding wheel 12 is provided with a grinding depth control 14, so that the grinding wheel 12 can be adjusted continuously according to their wear on the rail 1. This grinding depth control 14 comprises a measuring device for measuring the continuously decreasing diameter of the circumference of the grinding wheel 12; It can also rely on measurement data from measurements of the drive torque.

Both the milling chips and the grinding chips or the grinding dust are sucked immediately after their emergence, u.zw. via suction devices 15 and 16.

Immediately before the milling unit 7 and immediately after the grinding unit 11 guides 17 are provided for the rail 1 against which the rail 1 can be pressed by means of support rollers 18, wherein at least the driving mirror 4 of the rail 1, preferably the vertex of the rail head 3, can be pressed , Furthermore, along the device on both sides of the rail head 3 attacking side guide rollers 19 are provided, wherein the voltage applied to side of the running edge 6 of the rail 1 side guide rollers 19 are fixed in position. The rail is pressed by the voltage applied to the opposite side side guide rollers 19 against the fixed side guide rollers 19, whereby the rail 1 assumes an exact position relative to the milling unit and grinding unit.

Between the milling unit 7 and the grinding unit 11, a further guide 20 is provided, which is provided with a damping in order to eliminate vibrations caused by the cutter on the rail 1.

As in particular from Fig. 2 can be seen, the axis 21 of the grinding wheel is inclined relative to a plane perpendicular to the longitudinal direction of the rail 22 by an angle α which is greater than 0, preferably between 1 and 20 °, u.zw. in each case depending on the state of the rail present before grinding. If the rail head 3 already has a cross-section close to the ideal cross-section before grinding, or if the rail 1 is still provided with a rolling skin when new, then the angle α is expedient between 5 and 12 °, ideally at 8 °. However, if the pre-condition of the cross-section is less closely matched to the ideal cross-sectional profile, eg only roughly roughed, a smaller angle α, preferably between 1 and 6 °, is expedient for ensuring an optimum chipping volume with a long service life of the grinding wheel.

The grinding wheel 12 is already pre-profiled in the new state, i. it has approximately the opposite profile to the rail 1. In order to produce this counter profile exactly, it is advantageous to provide a stripper 23 with a honing stone 24, which can be pressed against the circumference of the grinding wheel 12. This Abziehstein has exactly the desired profile to be produced and he also closes the angle α with the grinding wheel. This Abziehstein 24 is pressed against the grinding wheel 12 before the beginning of the grinding of the first rail 1 until it has adopted its profile. During the grinding of the rail 1, the honing stone 24 can be lifted off the grinding wheel 12, because the grinding wheel profiled itself on the preliminary profile, i. on the milled rail head surface or on the still provided with the mill scale rail head surface. The whetstone may optionally be employed for temporary sharpening on the grinding wheel 12 during the machining of a rail head 3 to the grinding wheel 12.

To set an exact Gegenprofiles the grinding wheel 12 and the rail 1, if it is milled sufficiently accurate or still has the rolling skin, are used.

If, as in the illustrated embodiment, a milled rail head surface is ground, the profiled grinding wheel 12 has primarily only the task of smoothing the waves generated by the cutter 8 and to produce a longitudinal grinding pattern.

The inventive tilting of the grinding wheel 12 results in particularly good engagement conditions and a high smoothness effect. The engagement of the slanted Grinding wheel 12 is in Fig. 5 illustrated. It can be seen that the inclination results in a favorable pressure angle, in particular at the transition of the convex part 5 of the rail head 3 in the side surfaces 25 of the rail head 3. These favorable conditions of engagement also allow at these points a sufficiently large removal of material with very good thermal behavior, so that no fire can occur on the ground surface. Furthermore, this results in a very good service life of the grinding wheel 12th

It may be advantageous if the axis 21 of the grinding wheel 12 with respect to the longitudinal plane of symmetry plane 26 of the rail is also inclined, u.zw. by an angle β whose size can be between 1 and 20 °.

If different rail profiles are to be machined with the device according to the invention, the axis 21 of the grinding wheel 12 can expediently be arranged so as to be adjustable on the device.

According to the in Fig. 3 illustrated embodiment, the milling unit 7 and the grinding unit 11 are installed in a Schienenfräszug 27. The cutter 8 and the grinding wheel 12 are moved approximately vertically by means of adjusting devices 28 against the rail 1 until the guides 17 and 20 rest on the rail head 3. A movement of the grinding unit 11 and the milling unit 7 in the lateral direction to the running edge 6 is also possible until side guide rollers 19 abut against the rail head 3.

The rail profile cutter 8 according to the invention is constructed as a sandwich cutter, ie it is composed of disks 30, which are configured in each case as annular disks. These annular disks 30 carry, as will be described below, in each case a plurality of inserts 31. These are made of hard metal, ceramic or similar material. How out Fig. 6 can be seen, the annular discs 30 are attached to a Fräserkem 32 by means of a screw connection 33 and centered against each other by means of several centering pins 34 and secured by means of additional screws 35 against each other.

According to the illustrated embodiment, nine annular discs 30 are provided, the two outer annular discs 30 carry quadruple reversible plates whose cutting arc designed, and for milling, ie generating a milling track, near the driving edge 6 serve. The arranged between the outer annular discs 30 washers 30 are provided on the outer periphery 36 with the outer periphery 36 superior bumps 37, which are made in one piece with the annular discs 30. These humps 37 form the seats for quadruple inserts 31, which however have straight cutting. By provided on the annular discs 30 bumps 37 lying between the inserts 31 large-scale chip pockets 38 are formed.

All inserts 31 are secured to the annular discs 30 preferably by means of screw, there could also be used clamp connections. Each of the cutting edges of the turning plates 31 of the annular disks 30 arranged between the outer annular disks 30 projects with its cutting edge over the side surfaces of the annular disk 30 to which it is fastened. The arranged on the annular discs 30 inserts 31 adjacent annular discs 30 are arranged circumferentially offset, so that the inserts 31 of the adjacent annular disc circumferentially between the inserts 31 of the first annular disc 30 come to rest.

With the sandwich cutter 8 according to the invention, it is possible to mill very many - even more than nine - milling tracks extending in the longitudinal direction of the rail 1 on the rail head 3, as a result of which a very high accuracy of the milled cross-sectional profile can be achieved, i. a very high approximation to the ideal cross-sectional profile of the rail head 3. For certain requirements, the rail heads 3 reprofiled with the milling cutter 8 according to the invention or the milling method according to the invention, without subsequent grinding, e.g. for not too high speeds. For higher requirements, the milled tracks, as described above, subjected to a grinding process.

The main advantage of the grinding method according to the invention lies in the large number of side-by-side milling tracks, which can be milled onto the rail head 3 in a single operation. Of particular advantage, the milling method according to the invention is combined with the grinding method according to the invention, whereby a high material removal can be achieved even with heavily worn rails and the milling profile according to the invention the desired rail profile already largely corresponding surface can be achieved, which, if anything, only one more minor grinding, ie grinding with relatively little material removal, requires.

This makes it possible to combine milling and grinding in a single pass and thereby produce a driving mirror or a machined part of the rail head, which meets the highest requirements in terms of running characteristics, durability and noise prevention.

Claims (24)

1. Method of re-profiling, by peripheral milling, at least the running surface (4) of a rail (1), preferably the convex portion (5) of the rail head cross-sectional profile of a rail (1) incorporating the running surface (4), especially a railway rail, whereby in order to produce the desired profile by means of one device in a single peripheral milling operation, more than five, preferably nine, milling tracks lying adjacent to one another in the longitudinal direction of the rail are provided, wherein at least the running surface (4), preferably the convex portion (5) of the rail head cross-sectional profile incorporating the running surface (4), is ground by means of the device in the same machining operation.
2. Method according to claim 1, wherein the two outer milling tracks have a curved cross section and the milling tracks lying between the outer ones have a cross section extending in a straight line so that the rail head cross-sectional profile between the outer milling tracks is configured in the manner of a polygonal line.
3. Method according to claim 1 or 2, wherein corrugations of the milling tracks extending in the longitudinal direction of the rail (1) are disposed in a mutually offset arrangement so that valleys and peaks of a milling track assume a position offset from the valleys and peaks of adjacent milling tracks in the longitudinal direction.
4. Method according to one or more of claims 1 to 3, wherein the milling tracks are milled by the down-cut milling method.
5. Method according to one or more of claims 1 to 4, wherein the axis (21) of the grinding wheel (12) subtends an angle α with a plane (22) perpendicular to the longitudinal direction of the rail (1) that is not 0°.
6. Method according to claim 5, wherein the axis (21) of the grinding wheel (12) subtends an angle α with the plane (22) perpendicular to the longitudinal direction of the rail (1) of between 1 and 20°.
7. Method according to claim 6, wherein the angle α is between 5 and 12°, preferably approximately 8°.
8. Method according to one or more of claims 5 to 7, wherein the axis (21) of the grinding wheel (12) subtends an angle β with a plane of symmetry of the rail (1) lying in the longitudinal direction of the rail (1) of approximately 90°
9. Method according to one or more of claims 5 to 7, wherein the axis (21) of the grinding wheel (12) subtends an angle β with a plane of symmetry (26) lying in the longitudinal direction of the rail (1) that is smaller than 90° and greater than 70°, this angle β being maintained on the side of the guiding surface (6) of the rail (1).
10. Method according to one or more of claims 5 to 9, wherein the grinding wheel (12) is re-positioned as a function of the grinding wheel wear, preferably automatically, in the direction towards the rail (1) by means of a grinding depth regulating means.
11. Method according to claim 10, wherein the grinding depth is regulated by applying measurement data obtained by measuring the diameter of the grinding wheel surface or by applying measurement data obtained by measuring the driving moment of the grinding wheel (12).
12. Method according to one or more of claims 5 to 11, wherein the grinding wheel (12) is profiled by means of a grinding stone (24), and the grinding stone (24) has the same profile as at least the running surface (4) of the rail (1), and its longitudinal direction subtends the same angles α and β with the grinding wheel (12) as the rail (1).
13. Method according to claim 12, wherein profiling is carried out prior to the start of grinding the running surface (4) of the rail (1) and then only optionally during grinding and at longer time intervals.
14. Method according to one or more of claims 5 to 13, wherein the relative longitudinal motion between the rail (1) and milling cutter (8) as well as the grinding wheel (12) is generated by longitudinally displacing the rail (1) relative to the milling cutter (8) and grinding wheel (12).
15. Method according to claim 14, wherein, immediately before engaging the milling cutter (8), the rail (1) is pressed against a guide (17) directed towards the running surface (4) of the rail (1) and, between the milling cutter (8) and grinding wheel (12), against a guide (20) directed towards the running surface (4) of the rail (1).
16. Method according to claim 15, wherein the guide (20) is damped in order to prevent vibrations.
17. Method according to one or more of claims 14 to 16, wherein, immediately before engaging the milling cutter (8) and immediately before engaging the grinding wheel (12), the rail (1) is pressed against lateral guide rollers (19) lying alongside the guiding surface (6) of the rail (1).
18. Method according to one or more of claims 14 to 17, wherein, immediately after engaging the grinding wheel (12), the rail (1) is pressed against another guide (17) directed towards the running surface (4) of the rail (1).
19. Method according to one or more of claims 14 to 18, wherein, immediately after engaging the grinding wheel (12), the rail (1) is pressed by means of lateral guide rollers (19) against lateral guide rollers (19) lying alongside the guiding surface (6) of the rail (1).
20. Method according to one or more of claims 5 to 19, wherein the milling and grinding chips are sucked up as soon as they are created.
21. Method according to one or more of claims 5 to 20, wherein grinding is carried out by the down-cut method.
22. Method according to one or more of claims 5 to 12, wherein the relative longitudinal motion between the rail (1) and milling cutter (8) as well as the grinding wheel (12) is generated by moving the milling cutter (8) and grinding wheel (12) longitudinally along a laid rail (1).
23. Method according to claim 22, wherein the milling cutter (8) as well as the grinding wheel (12) are moved towards the rail (1) until engagement is established, and the movement is restricted in each case by means of a guide (17, 20) which can be pressed against the running surface (4) of the rail (1), independently of the system for regulating the grinding depth.
24. Method according to claim 22 or 23, wherein the milling cutter (8) and the grinding wheel (12) can be moved in the direction towards the guiding surface (6) of the rail (1), which movement is restricted in each case by means of guide rollers (19) lying alongside the guiding surface (6) of the rail (1).

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