METHOD FOR MACHINING THE RUNNING SURFACE OF A RAIL

Abstract

The system described herein relates to machining the running surface of a rail by means of at least one rotating, chip-removing shaping tool which can be moved along the rail and can be pressed at least against its running surface. In order to create advantageous design conditions, it is proposed that after the machining with the chip-removing shaping tool at least one rolling body which is adapted to the shape-machined rail surface is rolled over the rail, with cold deformation of the running surface of the rail, in order to level out unevenness of the running surface of the rail.

Claims

1. Method for machining the running surface of a rail with the aid of at least one rotating, chip-removing shaping tool, comprising: moving the chip-removing shaping tool along the rail; pressing the chip-removing shaping tool against the running surface of the rail; and after moving and pressing with the chip-removing shaping tool, rolling at least one rolling body over the rail, with cold deformation of the running surface of the rail, in order to level out unevenness in the running surface of the rail.

2. Method according to claim 1, wherein the rolling body is rolled over the rail with a leading or trailing slip of between 0.001 and 20%.

3. Method according to claim 1, wherein the rolling body consisting of a higher-strength material than the rail is rolled over the rail with a predetermined finely structured surface structure and wherein the surface structure is plastically pressed into the rail in the rollover process.

4. Method according to claim 1, wherein the rolling body is rolled over the rail with a nominal contact pressure of 0.8 to 2.

5. Method according to claim 1, wherein at least two rolling bodies are rolled over the rail one after the other with cold deformation of the running surface of the rail.

6. Method according to claim 5, wherein the rolling bodies are rolled over the rail with different slip and/or different surface structure and/or different contact pressure.

7. Device for machining the running surface of a rail with a rail-guided machining vehicle comprising: at least one rotating, chip-removing shaping tool which can be moved along the rail and can be pressed against the running surface thereof to provide a shape-machined rail surface; and a first rolling body adapted to the shape-machined rail surface arranged downstream of the chip-removing shaping tool in a working direction (5), wherein the first rolling body is moveable along the rail with the machining vehicle for leveling unevenness of a running surface of the rail, with cold deformation of the running surface of the rail, the first rolling body being pressed against the running surface of the rail by an actuating drive.

8. Device according to claim 7, wherein the first rolling body is equipped with a rotary drive and/or brake drive which rolls the first rolling body over the rail with a leading or trailing slip of between 0.001 and 20%.

9. Device according to claim 7, wherein the first rolling body consists of a higher-strength material than the rail and has a predetermined finely structured surface structure with a roughness depth of <10 μm.

10. Device according to claim 7, wherein the first rolling body is pressed with the actuating drive against the running surface of the rail with a nominal contact pressure of 0.8 to 2.

11. Method according to claim 4, wherein the rolling body is rolled over the rail with a nominal contact pressure of 1.2 to 1.75 GPa.

12. Device according to claim 9, wherein the surface structure has a roughness depth of <1 μm.

13. Device according to claim 10, wherein the first rolling body is pressed with the actuating drive against the running surface of the rail with a nominal contact pressure of 1.2 to 1.75 GPa.

14. Device according to claim 7, further comprising: a second rolling body that is rolled over the rail following the first rolling body to provide cold deformation of the running surface of the rail.

15. Device according to claim 14, wherein the rolling bodies are rolled over the rail with different slip and/or different surface structure and/or different contact pressure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In the drawings, the subject matter of the system described herein is shown schematically, for example, wherein:

[0020] FIG. 1 shows a machining vehicle with a device according to the system described herein in side view,

[0021] FIG. 2 shows an enlarged side view of a detail of the device from FIG. 1 in side view,

[0022] FIG. 3 shows a rolling body rolling on a rail in inclined view,

[0023] FIG. 4 shows a diagram showing the leveling of longitudinal waves caused by the milling cutter and

[0024] FIG. 5 a diagram showing the leveling of cutter-related transverse waves (corrugations).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The device for machining the running surface 1 of a rail 2 with a rail-guided machining vehicle 3 includes at least one rotating, chip-removing shaping tool 4 which can be moved along the rail and pressed against its running surface 1. A rolling body 6 adapted to the shape-machined rail surface is arranged downstream of the shaping tool 4 in a working direction 5 extending in the longitudinal direction of the rail. The rolling body 6 may be moved along the rail 2 with the machining vehicle 3 for the purpose of leveling unevenness of the running surface 2 of the rail, with cold deformation of at least the running surface, in particular the shape-machined rail surface, of the rail 2, and can be pressed with an actuating drive 7 against the running surface 1 of the rail with a defined setting force F.sub.A. The machining vehicle 3 may, if necessary, consist of two or more carriages, which may operate independently, for example at least one for the shaping tool 4 and at least one for the rolling bodies 6.

[0026] The rolling body 6 is equipped with a rotary drive 8, which rolls the rolling body over rail 2 with a leading or trailing slip s of between 0.001 and 20%. The rotary drive 8 can also act as a brake drive. The rolling body 6 is made of a higher-strength material than the rail and has a predetermined, particularly finely structured surface structure 9 with a roughness depth of <10 μm, particularly <1 μm.

[0027] The rolling body, for example, has a diameter D of less than 50 mm and is pressed against the running surface of the rail by the actuating drive 7 with a nominal contact pressure of 0.8 to 2, in particular of 1.2 to 1.75 GPa. The nominal contact pressure prevails in the contact area between rail and rolling body.

[0028] Numerical investigations have shown that it is possible to influence the surface condition in the desired sense after rolling over the previously abrasively machined rail with specifically selected contact parameters (rolling body diameter, contact pressure and, depending on geometry and load, between 0.001 and 20% with a leading or trailing slip). A defined rollover of the rail with the rolling body leads to a leveling of the roughness peaks.

[0029] FIG. 4 shows a calculation of the leveling of longitudinal wave peaks (normal to the longitudinal direction of the rail) by plotting the surface coordinates before and after several simulated rollovers with a contact pressure of 1.25 GPa and a braking slip of 1.5%. The rail extends in the direction of the x-coordinate. The z-coordinate corresponds to a rail vertical axis. For a wave peak height of 12 μm one rollover cycle is sufficient under the given conditions to level the wave. In particular, a leveling of longitudinal waves when rolling over with a smooth rolling body is shown. The contact pressure corresponds to 1.25 GPa, with a lagging, i.e. braking, slip of 1.5%. The rail steel has a quality of R260. One rollover cycle is sufficient for sufficient leveling.

[0030] FIG. 5 shows the leveling of transverse waves (corrugations). The y-coordinate corresponds to a rail transverse axis. A leveling of transverse waves when rolling over with a smooth rolling body is shown for two exemplary cases. Once with a contact pressure of 1.52 GPa and a second time with a contact pressure of 1.69 GPa, with a lagging slip of 1.5% and a rail steel of quality R260. With the aforementioned selected parameters, a transverse shaft can be leveled substantially with only one overrolling and comparable in size to the leveling by grinding directly after rail milling.

[0031] The system described herein is not restricted to the described embodiments. It may be varied within the scope of the claims, taking into account the knowledge of the relevant person skilled in the art. Other embodiments of the system described herein will be apparent to those skilled in the art from a consideration of the specification and/or an attempt to put into practice the system described herein. It is intended that the specification and examples be considered as illustrative only, with the true scope and spirit of the invention being indicated by the following claims.