DEVICE AND METHOD FOR GRINDING A PROFILE

Abstract

The invention relates to a method and a device (1) for grinding a profile of a rail track intended for rail-bound vehicles using a grinding body. The support is arranged on the device (1) for translatory movement in a plane transverse to the profile by means of a guide (12) and can be applied against the profile by a contact element (13, 14) such that the support carrying the grinding body automatically aligns itself in the transverse plane in respect of the profile and in respect of the device (1). Furthermore, the support for the grinding body can be moved in a translatory oscillating manner parallel to a longitudinal axis of the profile during rotational movement, such that a profile section is worked by the grinding body multiple times and the grinding outcome is substantially improved by the translatory movement.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2021/082672, filed on Nov. 23, 2021, and claims benefit to German Patent Application No. DE 10 2020 134 657.3, filed on Dec. 22, 2020. The International Application was published in German on Jun. 30, 2022 as WO 2022/135814 A2 under PCT Article 21.

FIELD

Embodiments of the present invention relate to a mobile device which is designed as a rail-bound vehicle for grinding a profile. Embodiments of the present invention further relate to a method for grinding the profile.

BACKGROUND

DE 69 201 811 T2 has already disclosed a mobile device which is designed as a rail-bound vehicle and which has a plurality of grinding wheels for grinding a rail track with a convex running surface and a defining side surface. The device is movable in the feed direction along the rail track, while the grinding wheels can be driven at the same time in a rotationally movable manner about an axis of rotation. The grinding wheels have in each case an inclined axis of rotation which does not intersect the rail profile, the grinding wheels being arranged on a frame of the rail-bound vehicle which is displaceable transversely to the rail track and being guided by means of rollers which bear against the rail track. The frame serves to displace the support both in a transverse direction and perpendicular to the longitudinal axis of the rail. The support has at least one support roller which is arranged in the immediate vicinity of the axis of the corresponding grinding wheel. These support rollers are applied against the inner face of the rail head.

DD 219 230 A5 describes a device for re-profiling a rail head, wherein the axis of rotation of the grinding wheel is inclined relative to the vertical and the horizontal plane. The grinding wheel is guided vertically and laterally relative to the rail on a grinding frame by means of grinding shoes or rollers. The grinding wheel has a planar grinding surface which is post-machined by a pin serving for dressing the grinding wheel during the grinding process. The convex rail head is thus only partially machined, so that facets are generated thereby and the rail transverse profile is provided with a discontinuous path.

Inclined counter-rotating grinding wheels with offset axes which do not intersect the profile are disclosed in DE 26 12 173 A1, the grinding wheels being mounted on tool supports which are vertically and transversely displaceable by means of a tracking system assigned to each rail. The grinding tools arranged on each rail side act on the rail head upper face with the same delivery movement, wherein the transverse displaceability of the two frame parts relative to one another results in a centering relative to each rail independently of one another.

Moreover, a grinding device is disclosed in DE 32 27 343 A1 in which a tool support is arranged in a height-adjustable manner below a chassis for each of the rails, the tool support guiding a rotatable machining tool, in particular a cup grinding wheel, in a defined manner via lateral rollers which run on the profile, the axis of rotation of the machining tool intersecting the profile of the rail.

In a rail-bound vehicle according to EP 2 791 422 B1, face milling profiling wheels are arranged on a chassis on a machining plate which is adjustable in terms of angle relative to the rail in the vertical and transverse direction as a compound slide in a linear manner and additionally about the longitudinal and vertical axis, wherein measuring sensors sliding on the rail supply the reference variable for the adjustment. The tracking of the tool on the rail can take place, for example, by means of an articulated robot.

The device disclosed in U.S. Pat. No. 4,583,893 A comprises a support element which can be displaced in a linear manner relative to a rail and which comprises a contoured milling cutter. A cutting depth reference guide for the tool bearing can be applied against the upper face of the running surface of the rail and a lateral cutting depth reference guide can be applied against the side surface. The two cutting depth reference guides are rotatably mounted about a common shaft and are arranged in the feed direction in front of the milling cutter.

Due to relatively high axle loads and high travel speeds rails are often stressed up to the yield point of the rail material, and thus are subjected to wear which has a negative effect on the profile of the running surface of the rail head.

Due to ongoing wear, the running surfaces of railroad tracks do not remain straight but form corrugations of different lengths over time. These corrugations are removed by grinding the rails, wherein corrugations of longer lengths cause certain problems for the device.

To remove the ripples and corrugations produced on the running surface of rail tracks during operation, which stimulates the wheel sets of the vehicles to vibrate, disrupts the smooth running of the vehicles, causes an excessive wear of the track superstructure and the vehicles and can produce whistling driving noises, it is necessary to grind the heads of the railroad tracks flat from time to time.

To this end, grinding devices are known, the grinding devices having at least two cup wheels which are arranged one behind the other in the longitudinal direction of the rail head and which are applied against the running surface on the front face on opposing sides of the rail head, and which have a grinding profile corresponding to the running surface profile.

To this end, for example, a method for machining railroad tracks is known in which a plurality of rotating grinding wheels is used, the grinding wheels being arranged adjacent to one another and one behind the other, wherein some of the grinding wheels are inclined according to the original profile of the rail heads. Only an approximation to the original profile of the rail heads can be achieved by such a grinding method.

EP 0 315 704 B1 has already described a grinding machine for re-profiling rail heads with a grinding head which can be adjusted by a lifting device, wherein the grinding heads can be lifted and lowered successively and offset to one another.

An arrangement of grinding modules in a rail grinding machine is disclosed in WO 00/58559 A1 which takes into account the radial offset in the case of narrow radii of curvature of the rails without the presence of constraining forces and permits the re-profiling of the rail in a simple manner. The grinding tool has five degrees of freedom in which each grinding module is mounted with a frame so as to be at least approximately vertically adjustable and is mounted on the frame so as to be at least approximately horizontally adjustable with a chassis.

So-called cup grinders are also known, the cup grinders being brought into engagement on the front face with the rail surface and preferably being set with a tilting angle relative to the rail surface to be ground.

In so-called offset grinding, a front surface of the grinding tool is also used for machining the rail but is contoured according to the rail geometry. This is made possible by the axis of rotation not running through the rail but with a lateral spacing thereto. The grinding zone is thus not located in front of the axis of rotation in the direction of the feed movement but transversely between the axis of rotation and the rail. In order to achieve a sufficient removal capacity, a high rotational speed and/or high pressing force is set. In practice, this leads to flying sparks and thus to the risk of fire.

EP 2 525 933 B1 relates to a device for material-removing post-machining of the running surface of a rail head with a frame guided along the rail head. The machining tools are configured as face milling cutters which can be driven so as to rotate in opposing directions, the axes of rotation thereof running in a common plane and the cutting regions thereof overlapping one another transversely to the longitudinal direction of the rail head.

Further devices for grinding are described in the publications U.S. Pat. No. 4,583,895 A1, DE 32 27 343 A1, DE 28 01 110 A1 and EP 1 918 458 A1.

Devices for grinding a rail with a grinding belt running parallel to the rail longitudinal axis have already been disclosed in CH 670 667 A5, U.S. Pat. No. 5,997,391 A, DE 41 19 525 A1 and JP 2003-053655 A. During the grinding process, the grinding belt is pressed against the rail to be ground by a profiled sliding shoe, a movable pressure shoe, or by a pressure element. Moreover, DE 20 2005 012 147 U also relates to a device for grinding a rail with a contact roller which is shaped according to the rail head and by which a grinding belt is pressed against the rail head.

A device for grinding a rail running surface with a grinding belt aligned parallel to the rail longitudinal axis is also disclosed in EP 0 444 242 A1, wherein a further belt which is configured as a pressure belt is arranged between the pressure rollers and the grinding belt.

So-called sliding stones are also used for profile-grinding the heads of railroad tracks. In this case grinding trains are used, grinding stones being arranged on the underside thereof and being guided under pressure over the rail surfaces. Grinding by sliding stones is based on an oscillating translatory movement of the grinding body along the rail during the movement of the vehicle. By contouring the grinding bodies, which during use also substantially maintain their shape even with increasing wear, in principle a good surface quality and dimensional accuracy is achieved.

A drawback of the grinding method using sliding stones is that after a short time the sliding stone is already adapted to the worn profile of the rail surface, so that while a removal of ripples and corrugations in the rail surface is achieved, it is not possible to restore the original profile of the rail head.

In order to increase the travel speed which is achievable with sliding stones, DE 21 32 220 A proposes to provide a grinding means support which can be fastened to the grinding train and which has individual guide channels which face toward the rail surface for a relatively coarse-grained grinding means with loose grit which is supplied through the channels under pressure to the rail surface and held there by the channel walls, wherein the lower defining edges of the guide channels have a spacing relative to the rail surface which is smaller than the grain size of the grinding means. As a result, only relatively small and short chips are formed, the chips being able to be removed in a simple manner. Heat build-up due to plaque formation and any risk of rupture are thus effectively avoided.

To increase the machining speed, it is disclosed in DE 32 22 208 A1, for example, to use milling cutters, the cutting edges thereof which are distributed in a plurality of axial groups over the periphery of the cutter head replicating the rail head profile.

The arcuate cutting path of the individual cutting edges of the milling cutter caused by such peripheral milling, however, leads to a surface of the rail head which is corrugated in the rail longitudinal direction, wherein the surface quality is impaired with an increasing feed rate due to the increasing distance between the material removal of successive cutting edges.

These drawbacks are remedied by face milling cutters, as disclosed in U.S. Pat. No. 4,583,893 A for example, the face milling cutters being arranged on one side of the rail head and being used with a complex guide which has a freely rotatably mounted guide wheel and a plurality of guide rollers on the opposing rail side.

Similar drawbacks occur in a device according to EP 0 148 089 A2 in which the running surface is machined on both sides of the longitudinal center by a milling head, which is configured as a face milling cutter but has to be used with a correspondingly inclined axis, since peripheral milling cutters for the longitudinal sides of the rail head have to be arranged upstream or downstream of this common milling head.

WO 02/06587 A1 also describes a method for re-profiling at least the convex part of the rail head cross-sectional profile of a rail by peripheral milling, with more than five milling tracks adjacent to one another in the longitudinal direction of the rail.

Further devices for material-removing post-machining, in particular for milling rail heads laid in the track, are described in the publications EP 0 952 255 B1, U.S. Pat. No. 5,549,505 A, EP 0 668 398 B1, EP 0 668 397 B1, U.S. Pat. No. 4,275,499 A and DE 32 22 208 C2.

Devices are also known in which the rail heads are machined with a so-called rail planer. The publication DE 28 41 506 C2 discloses such a device in which the material-removing planer blades machine the rail with a continuous feed movement. Flat surfaces can be generated by means of the planer, the surfaces having only negligible machining marks relative to milling. A drawback with planing, primarily compared to the milling method, is a relatively long machining time due to the repeated passes needed over the rail portion to be machined.

In order to obtain a flat surface, EP 2 177 664 A1 proposes to move the cutting edge along a straight path during the material-removing machining of the workpiece.

When machining a rail track by means of milling cutters, a significant amount of material is removed but the surface quality thus generated requires post-machining by finishing. In contrast, a smaller amount of material is removed by the known grinding method than by milling. However, higher feed rates can be achieved during grinding, so that in practice due to the respective boundary conditions both milling and grinding methods are used.

Thus it is currently usual to machine the rails in one operation with a milling cutter and to reduce the machining marks which occur on the machined surface as a result of the milling, such as corrugations or track patterns, by grinding.

SUMMARY

Embodiments of the present invention provide a device configured as a rail-bound vehicle for grinding a profile with a running surface and a side surface defining the profile. The device includes at least one profiled grinding body that is capable of being driven in a rotationally movable and/or oscillating manner about an axis of rotation. The at least one grinding body is concave at least in some portions. The axis of rotation is capable of being positioned so as to be inclined with an orientation relative to a vertical plane and/or relative to a horizontal plane. The device further includes a support arranged on the device so as to be movable in a translational manner in a transverse plane relative to the profile and/or relative to a feed direction via a guide. The at least one grinding body is arranged on the support. The device further includes at least one contact element that is coupled to the support and is capable of being applied against the profile in a region of a contact surface of the profile. The support with the grinding body is automatically aligned thereby in the transverse plane relative to the profile and relative to the device. The axis of rotation of the at least one grinding body, with a transverse axis relative to a longitudinal axis of the profile, spans a plane which intersects at least one contact surface of the at least one contact element on the profile.

BRIEF DESCRIPTION OF THE DRAWINGS

Subject matter of the present disclosure will be described in even greater detail below based on the exemplary figures. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following:

FIG. 1 shows a cross section through a profile and a grinding body arranged inclined at an angle of 35° according to an embodiment;

FIG. 2 shows a further view of the profile with a grinding body arranged inclined at an angle of 5° according to an embodiment;

FIG. 3 shows a front view of a support of a device with the grinding body shown in FIG. 1 according to an embodiment;

FIG. 4 shows a front view of the support with a grinding body arranged inclined at an angle of 5 according to an embodiment;

FIG. 5 shows a front view of the support during the adjustment of the position and orientation according to an embodiment;

FIG. 6 shows a side view of the support during the adjustment of the position and orientation according to an embodiment;

FIG. 7 shows an enlarged cross section through the profile according to FIG. 1 according to an embodiment; and

FIG. 8 shows two grinding bodies with axes of rotation inclined toward one another in a front view according to an embodiment.

DETAILED DESCRIPTION

Embodiments of the present invention can improve substantially the removal capacity when grinding profiles, at the same time with high demands for the surface quality and the dimensional accuracy of the profile thus machined.

Embodiments of the present invention provide a device for grinding, in which the axis of rotation can be positioned to be inclined with an orientation relative to the vertical plane and/or relative to the horizontal plane, and the axis of rotation does not run through the profile, and in which the support is arranged in a transverse plane on the device, in particular, so as to be movable in a translatory manner relative to the transverse plane to the feed direction, and the support is kinematically coupled to at least one contact element which can be applied non-positively against the profile as lateral copying and/or vertical copying, by which the support with the grinding body is automatically aligned in the transverse plane relative to the profile and relative to the device.

The inventors recognized that it is possible to maintain small tolerances when machining the profiles by means of the mobile device designed as a rail-bound vehicle, by the support of the grinding body being movable both relative to the profile and relative to the mobile device and being automatically aligned during use of the device. At the same time, the working result is achieved irrespective of wear occurring on the grinding body, which thus does not have a negative effect on the quality of the surface machining.

The automatic alignment could take place on the basis of contactless distance measurements. According to embodiments of the invention, the device is provided with a contact element, for example a sliding element, such as a slide, or an arrangement with at least one roller or a wheel. As a result of contact-based lateral and/or vertical copying, the support of the grinding body is moved in its guide in the transverse plane and thus adapted to the grinding wheel wear. However, the contact element also ensures a compensation of the displacement in the direction of the outside of the curve, which occurs in practice due to the forced guidance of the mobile device during cornering.

Such a forcibly guided lateral copying is preferably non-positively applied against the internal or medial side surface facing the respective other rail track.

It has already been shown to be expedient if the support bears at the same time a paired arrangement of a plurality of grinding bodies which are arranged in a common transverse plane of the device, such that the grinding bodies can be aligned together both relative to the parallel rail tracks and relative to one another. Since a separate contact element is assigned to each grinding body, it is also possible to compensate for inaccuracies of the profile along its main extent or deviations from the ideal parallel alignment of the rail tracks. To this end, the contact element is pretensioned with a predetermined, in particular adjustable, pretensioning force relative to the profile, in particular the rail track. As a result, the grinding bodies are spread apart from one another at the same time, so that in particular no additional abutment is needed for receiving the bearing force.

For the height adjustment, a further contact element which can be designed as a roller is pretensioned from above against the running surface of the profile or the rail track, in order to achieve in this manner an automatic adaptation in the vertical direction. However, the contact element can also have two bearing surfaces in order to permit the horizontal alignment relative to the side surface and the vertical alignment relative to the running surface at the same time with a single contact element.

It has already been shown that the device thus equipped is independent of the movement of the rail-bound vehicle during operation, due to the vertical and horizontal guidance of the supports and the grinding bodies connected thereto, so that for the first time a working platform does not form the reference for the adjustment of the tools, as in the prior art, but directly the profile itself to be machined, which clearly leads to substantially fewer errors.

It has been shown that the machining quality can be further improved by an arrangement of the grinding bodies in a common transverse plane of the device or the cross-sectional plane of the profile with the contact element assigned thereto. As a result, the position of the contact element as lateral copying is directly related to the center of rotation of the grinding body, which is designed in particular as a cup grinding wheel, so that no lateral offset occurs even in the case of cornering. Rather, the contour of the grinding body always remains in congruence with the profile.

It is preferred that the axis of rotation of the grinding body is oriented with a lateral or medial offset in the cross-sectional plane of the profile such that this axis of rotation does not intersect the profile. A negative shape of the profile is formed in the grinding body by a setting angle and an eccentric position of the cup grinding wheel. A contact surface which is of variable length in terms of its contact length is thus produced over the surface of the profile, which is distributed over the rail transverse profile. Due to this contact surface which is lengthened in the radius region of the profile, the grinding tool is automatically stabilized in the longitudinal direction which leads to an optimal flattening of the surface, in particular the residual corrugations of the profile.

It has also already been shown to be expedient if a plurality of grinding bodies are arranged on one respective support one behind the other in the feed direction, wherein the axes of rotation of the grinding bodies are not aligned in parallel but inclined relative to one another. Different setting angles of the grinding bodies generate different grinding regions on the surface of the profile. The entire transverse profile can be ground with two grinding bodies one behind the other at different angles, by different grinding bodies being used for machining different surface portions (tracks) with different inclination angles running parallel to one another in the direction of the main extent of the profile.

The grinding bodies can be operated in synchronism or counter-rotating, so that the rotational direction of the grinding bodies is identical in the feed direction and counter to the feed direction. As a result, with the material removal during the grinding process, a tangential removal stream is produced which always acts in the same direction irrespective of the direction of movement of the device by the rotating grinding body.

Since the rotational axes of the grinding bodies are not arranged parallel to the cross-sectional plane of the profile to be machined, but are oriented so as to be inclined in the feed direction or counter thereto, the larger surface component of the contact surface between the grinding body and the profile is located in front of or behind the plane of the axis of rotation. In this manner, a trailing or leading machining relative to the feed direction is implemented in a simple manner relative to a cross-sectional plane of the profile.

In this case, a trailing or following arrangement for hobbing or surface milling can also be implemented for smoothing the residual corrugations.

Different positions of the grinding body are conceivable. With a central positioning of the grinding body, i.e. if the axis of rotation runs through the profile, in particular the central longitudinal axis thereof, straight facets are produced, which has already proved expedient when rough grinding. A combination of a plurality of grinding bodies can also be expediently used, at least one axis of rotation thereof passing through the profile and at least one further axis of rotation having a lateral offset to the profile, wherein this is not oriented in a cutting manner.

With a combined used of the grinding bodies with at least one milling cutter, the milled rail transverse profile can be produced with a partial oversize so that an exact rail transverse profile is produced after grinding. This occurs when, after the milling process, the partial oversize protrudes in the region in which the grinding tool also corresponds in its normal (pressing direction=greatest grinding removal).

When carrying out the grinding process, the grinding bodies bear relative to the profile in a force-dependent manner, in particular with an adjustable or limitable pressing force or pretensioning force. The control of the pressing force or pretensioning force is carried out expediently by considering the relevant parameters of the profile and the surrounding conditions, wherein the detected torque of the grinding body and the feed rate of the device can also be included.

In order to be able to compensate for a rapid and reliable adaptation to different profiles, in particular rail tracks or variable conditions of use, and associated therewith different relative positions and orientations between the profile and the device, the support or the axis of rotation can be adjusted in a path-controlled manner.

In a further embodiment of the invention, which is also promising, for introducing a superimposed movement during the rotating and/or oscillating movement, the support is designed to be movable in a reversable translatory manner in a plane parallel to the main extent of the profile or the rail track. Since at least one of the grinding bodies, which is designed as a grinding wheel, is moved at the same time by a reversing translatory movement of the support provided with the grinding body in a plane parallel to the main extent of the rail track, during the rotating or oscillating movement to and fro along a specific circular path, the grinding means is repeatedly engaged in each rail portion. As a result, a rail portion is not only reached once by the grinding zone of the grinding body but passed over repeatedly by the grinding body and a corresponding high removal capacity is achieved. Surface qualities which are comparable with a sliding stone method can be implemented, wherein in particular corrugations in the rail surface can be reliably eliminated.

The shape of the rail track to be machined is not determined by the geometry of the grinding body but by the setting angle thereof, so that it does not lead to a deviation in size in the context of a rotating or oscillating movement. A combination of a plurality of grinding bodies known per se has already proved expedient here.

It is advantageous if the axis of rotation of at least one grinding body encloses an acute angle with the longitudinal axis of the profile. The reference shape of the grinding process to be generated is accordingly achieved by a plurality of grinding bodies, which together produce the desired profile. The axes of rotation of different grinding bodies enclose an acute angle relative to one another. Moreover, the setting angle of at least one grinding body can be designed to be adjustable, wherein preferably the angle of inclination of the respective axis of rotation is also designed to be adjustable during the operation of the device.

Moreover, the setting angle can also be selected according to the desired profile clearance, in order to be able to achieve optimal grinding results even under spatially restricted operating conditions.

According to a further embodiment of the invention, if the axis of rotation of the grinding body encloses an acute angle with the transverse plane of the rail track, a rapid transport of the material removed from the machining zone is achieved in a simple manner, so that the removed material cannot collect in the grinding gap.

Naturally, the grinding body has a rotationally symmetrical shape. A variant of the grinding body has at least in some portions a concave shape of the peripheral surface or the front surface, wherein the concave grinding surface is adapted to the geometry of the profile of the rail track.

In a preferred embodiment of the invention, the grinding body and/or the support has at least one electrical and/or hydraulic drive in order to provide the desired drive power and also to undertake a rapid change in the speed of the support or the grinding body by a deceleration or acceleration, and as a function of the respective operating conditions. The drive can be arranged centrally on the device or decentrally on the support, wherein a plurality of grinding bodies can be supplied with the required drive power by a common drive.

A further embodiment of the invention, which is also promising, is also achieved by the rotational or oscillating movement of the at least one grinding body, on the one hand, and the translatory movement of the support, on the other hand, taking place in a synchronized manner by a kinematic coupling. As a result, the rotational or oscillating movement is adapted to the movement sequence of the support, which due to the reversing translatory movement is decelerated in a cyclical manner at the reversal points. The change associated therewith in the relative movement of the grinding body relative to the rail track is compensated by the kinematic coupling. A superimposition of a different drive power of the grinding body can thus also be implemented in a simple manner by a further drive power provided by means of the kinematic coupling. For example toothed racks, connecting rods, coupling rods or the like can be used for the power transmission. In practice, an additional speed component of the rotation or oscillation of the grinding wheel rotation is superimposed on the at least one grinding body, primarily in a direction of movement of the support opposing the direction of travel. The lateral copying and the guide are pretensioned relative to the profile by a pretensioning force, while the grinding body, for example, can be lifted away on one side.

In a further advantageous modification of the invention, the drive power of the support is used as the sole drive power for the rotation of the grinding tool, by using the coupling.

In a further embodiment of the invention, which is also promising, the synchronized rotational or oscillating movement of the at least one grinding body, on the one hand, and the translatory movement of the support, on the other hand, takes place by a hydraulic, pneumatic or electromechanical coupling. The additional or sole drive power for the at least one grinding body is produced by the cyclical pressure increase or pressure reduction of the hydraulic or pneumatic pressure of the drive of the support, which is effective in the regions of the reversal points of the reversing movement. A distinction can also be made of the drive power provided in the rear and front reversal points. In this manner, for example, the relative speed of the grinding body which is moved in a rotational or oscillating manner, and also translatory manner, by means of the support relative to the rail track can be kept constant within predetermined limit values. To this end, a pressure accumulator can also be provided in order to be able to provide a drive power which is as uniform as possible.

Embodiments of the present invention provide a method for grinding a profile, in particular a rail track intended for rail-bound vehicles, in which at least one grinding body which is arranged on a support is driven in a rotationally movable or oscillating manner about an axis of rotation, in that during the rotational or oscillating movement of at least one grinding body, the support bearing the grinding body is driven at least temporarily in a reversing translatory manner for introducing a superimposed movement parallel to a longitudinal axis of the profile. Thus a repeated engagement of the grinding body takes place in each profile portion, in which the supports are moved to and fro in the longitudinal direction of the rail track, while the grinding body ensures the desired material removal by its rotational or oscillating movement. The axis of rotation of the grinding body is arranged, in particular, so as to be inclined at an acute angle relative to the plane of the surface portion to be machined and/or to the cross-sectional plane of the rail track. As a result, due to the inclined orientation of the axis of rotation of the grinding body, the removed material is transported away medially or laterally from the rail track and thus does not collect in an undesirable manner in the region of the grinding gap. Preferably, the axis of rotation is inclined such that the lateral axis portion is located in front of the medial axis portion relative to the rail track in the direction of travel. The medial side denotes the side facing the adjacent rail track and the lateral side denotes the side facing away from the adjacent rail track.

In comparison with the grinding methods known from the prior art with rotating grinding tools, the rotational speed can thus be reduced, whereby flying sparks are also significantly reduced during operation, while the relative speed can still be increased between the rail surface of the rail track and the grinding body.

Since the translatory movement of the grinding body follows a sinusoidal speed in the rail plane, the rotation is preferably controlled such that the rotational speed of the grinding body is increased in the region of the reversal points of the translatory reversing movement of the support. In particular, the rotational speed of the rotating movement of the grinding body is adapted reciprocally to the translatory movement.

Since the translatory movement is additionally superimposed by the traveling movement of the device along the rail, the translatory speed is added with the movement in the direction of travel and the translatory speed is subtracted with the movement counter to the direction of travel. The absolute translatory speed of the grinding body is not zero in the region of the reversal points during operation. Rather, the speed of the support between the reversal points in the direction of travel is greater than counter to the direction of travel. To compensate, the rotational speed is further reduced in the direction of travel but increased counter to the direction of travel.

A practical development of the method according to embodiments of the invention is also achieved in that the rotational speed or the frequency of the rotating or oscillating movement of at least one grinding body in the region of the reversal points of the translatory reversing movement is changed, in particular is increased, relative to a region between the reversal points, in order to compensate for the deceleration of the translatory movement of the support correspondingly by an increase in the rotational or oscillating movement. In particular, the change in the rotational speed or the frequency of the rotating or oscillating movement is adjusted in a reciprocal manner to the reversing translatory movement.

In a mobile device, in particular designed as a rail-bound vehicle, it has proved expedient if the rotational or the oscillating movement is adjusted to a lower rotational speed or frequency in the direction of travel than counter to the direction of travel. This compensates for the intrinsic movement of the mobile device along the rail track which is superimposed on the translatory movement of the support and, depending on the movement phase of the support, accordingly increased or reduced by this amount. In addition to this fundamental difference in the rotational or oscillating movement in the direction of travel and counter to the direction of travel, naturally the deceleration and acceleration occurring in the region of the reversal points of the reversing movement of the support can be compensated in this manner.

In a simple variant of the method, the rotational or oscillating movement of the at least one grinding body, on the one hand, and the translatory movement of the support, on the other hand, can be introduced kinematically coupled together in order to keep the control effort low.

In order to achieve an acceleration of the rotational or oscillating movement of the grinding body, with a deceleration of the support, the support can also be connected to an energy storage device, for example a pressure vessel, which is filled in the region of the maximum speed of the support. In the region of the reversal points of the movement of the support, the stored energy can be taken and used to increase the rotational speed or frequency of the grinding bodies.

It has also proved expedient if the grinding body is brought into contact with the surface of the rail track with a grinding surface on the peripheral side or front face, in order to be able to machine a large portion of the rail head by a corresponding contouring of the grinding body, and to ensure a high machining accuracy. An offset grinding method is preferably used in combination with milling.

A device 1 designed as a rail-bound vehicle for grinding a profile 2 which is designed as a rail track, in particular for grinding a running surface 3 by means of a grinding body 4, is explained in more detail hereinafter with reference to a schematic view in FIGS. 1 to 8. The device 1 which is shown in this variant is designed specifically for machining rail tracks which run parallel, as profiles 2 to be ground.

For better understanding, parallel rail tracks and the grinding bodies 4 which are assigned thereto and arranged mirror symmetrically and which are arranged together on the device 1, are shown in FIG. 3 by way of indication, as is explained hereinafter in further detail.

For the grinding process of the profile 2, the grinding bodies 4 are provided with a grinding surface 5 on the front face, with bonded grain and a geometrically undefined cutting edge. As can be identified, in particular, in FIGS. 1 and 2, different inclination angles α; β between 5° and 90° of an axis of rotation 6 of the grinding bodies 4 can be provided relative to a central longitudinal plane 7 of the profile 2.

According to an embodiment, the axis of rotation 6, as can be identified, is not only arranged inclined relative to the vertical and the horizontal but is additionally oriented eccentrically with an offset, such that the axis of rotation 6 of the grinding body 4 does not intersect the profile 2. Thus only a circular sector or a circular segment with a center angle of less than 180° is in contact with the profile 2. In contrast to a centered orientation of the axis of rotation 6 directed toward the profile 2, a concave grinding surface 5 of the grinding body 4 can be implemented in the radial direction relative to the axis of rotation 6. This concave shape 8 can be already introduced into the grinding body 4 in the production process, which in use is optimally adapted to the profile 2, so that the occurring wear cannot lead to an undesired shape deviation.

It should be emphasized that, due to this offset or eccentric positioning and the orientation inclined at the angle α, β of the axis of rotation 6 of the grinding body 4, not only is an optimal concave shape obtained for the first time but also the width b, B of the surface portion to be machined by the grinding body 4 and running in the cross sectional plane of the profile 2 is substantially larger than is possible by the tools known from the prior art and the resulting facets. Rather, it has been already shown that an optimal surface machining of the profile 2 according to embodiments of the invention requires no more than two grinding bodies 4 arranged one behind the other in the feed direction, and in some cases even only a single grinding body 4 is needed, as indicated in FIG. 1 in combination with FIG. 7.

In practice, the grinding surface 5 engages sufficiently far around the convex surface portion 9 between the running surface 3 and an inner side surface 10, which defines the profile 2 medially, that it permits a machining quality regarding dimensional accuracy and shape accuracy which was previously unachievable.

Each of the grinding bodies 4 is arranged on a support 11 which, to compensate for wear, permits an axial delivery of the grinding body 4 parallel to the axis of rotation 6 relative to the profile 2 and also an adjustment of desired inclination angle α, β which is optimal for the respective conditions of use.

The support 11 in turn is movable by means of a guide 12 in a translatory manner relative thereto in a plane parallel to the cross-sectional plane of the profile 2 or in the transverse plane to the feed direction of the device 1. As a result, during operation it is possible to maintain a constant position of the grinding body 4 which is always optimal relative to the profile 2, even when the device as a mobile rail-bound vehicle is in turn subjected to a movement relative to the profile 2, as is the case in principle with cornering. In such cases, the support 11 is moved to the side, wherein two supports 11 arranged in a common transverse plane are kinematically coupled together for the common adjustment of the respective grinding body 4, and thereby carry out a common movement.

The control of this lateral medial movement or lateral movement of the supports 11 is achieved by the support 11 being connected to at least one contact element 13, which can be applied non-positively against the profile 2, the support 11 being automatically aligned thereby with the grinding body 4 in the transverse plane relative to the profile 2 and relative to the device 1. To this end, the contact element 13, which is provided as a slide with a sliding surface, can be applied against the side surface 10 of the profile 2, while for detecting the height a further contact element 14 which is designed as a roller is supported from above against the running surface 3 so that the two contact elements 13, 14 together form a reference for the alignment of the grinding body 4, and the support 11 is automatically aligned relative to the profile 2 and relative to the device 1 due to an adjustable pretensioning force F in the transverse plane.

As shown by way of indication in FIG. 8, a plurality of, for example also different, grinding bodies 4 with differently inclined axes of rotation 6 can be arranged one behind the other on one respective support 11 in the feed direction of the device 1, wherein the axes of rotation 6 of the grinding bodies 4 enclose an acute angle (p. The grinding bodies 4 permit the machining of different surface portions 9 of the convex or planar surface as parallel tracks.

According to an embodiment of the invention, a superimposed reversing movement of the grinding body 4, which can be driven in a rotationally movable or oscillating manner about its axis of rotation 6, with its grinding surface 5 can be implemented when grinding the profile 2. The support 11 of the grinding body 4 is designed to be movable in a reversing translatory manner for introducing a superimposed movement during the rotating or oscillating movement of the grinding body 4 parallel to the central longitudinal plane 7 of the profile 2. Due to this translatory movement of the grinding body 4 superimposed on the rotational movement, the grinding body repeatedly reaches each surface portion of the profile 2 even when the vehicle bearing the device follows the path of the profile 2 at its own usual speed. As a result, a rail portion is not only reached once by the grinding surface 5 of the grinding body 4 but can be passed over repeatedly thereby so that very good surface qualities can be produced. The axes of rotation 6, which are inclined at the angle φ to one another, ensure that the removed material is transported out of the grinding gap and cannot accumulate therein. Due to the efficient machining and the high level of material removed, the rotational speed can be reduced and flying sparks can also be reduced thereby, in addition to the wear, while at the same time the relative speed is increased between the surface of the profile 2 and the grinding body 4.

Since the translatory movement of the support 11 between its reversal points follows a sinusoidal speed curve, and is additionally superimposed by the intrinsic movement of the vehicle, the rotation preferably can also be controlled such that the rotational speed of the grinding body 4 is increased in the region of the reversal points of the reversing movement. In particular, the rotational speed of the rotating movement is reciprocally adapted to the translatory movement. Since the translatory movement is also superimposed by the intrinsic movement of the vehicle along the profile 2, the translatory speed is added with the movement in the direction of travel and the translatory speed is subtracted with the movement counter to the direction of travel, so that the rotational speed of the grinding body 4 is also adjusted as a function of the leading or trailing phase.

While subject matter of the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Any statement made herein characterizing the invention is also to be considered illustrative or exemplary and not restrictive as the invention is defined by the claims. It will be understood that changes and modifications may be made, by those of ordinary skill in the art, within the scope of the following claims, which may include any combination of features from different embodiments described above.

The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

LIST OF REFERENCE SIGNS

• • 1 Device
  • 2 Profile
  • 3 Running surface
  • 4 Grinding body
  • 5 Grinding surface
  • 6 Axis of rotation
  • 7 Central longitudinal plane
  • 8 Shape
  • 9 Surface portions
  • 10 Side surface
  • 11 Support
  • 12 Guide
  • 13 Contact element
  • 14 Contact element
  • b, B Width
  • α, β, φ Angle
  • F Pre-tensioning force

Claims

1. A device configured as a rail-bound vehicle for grinding a profile with a running surface and a side surface defining the profile, the device comprising:

at least one profiled grinding body that is capable of being driven in a rotationally movable and/or oscillating manner about an axis of rotation, which is wherein the at least one grinding body is concave at least in some portions, and wherein the axis of rotation is capable of being positioned so as to be inclined with an orientation relative to a vertical plane and/or relative to a horizontal plane,

a support arranged on the device so as to be movable in a translational manner in a transverse plane relative to the profile and/or relative to a feed direction via a guide, wherein the at least one grinding body is arranged on the support, and

at least one contact element that is coupled to the support and is capable of being applied against the profile in a region of a contact surface of the profile, wherein the support with the grinding body is automatically aligned thereby in the transverse plane relative to the profile and relative to the device, and wherein the axis of rotation of the at least one grinding body, with a transverse axis relative to a longitudinal axis of the profile, spans a plane which intersects at least one contact surface of the at least one contact element on the profile.

2. The device as claimed in claim 1, wherein a plane of the axis of rotation of the grinding body is located parallel to a cross-sectional plane of the profile.

3. The device as claimed in claim 1, wherein a plane of the axis of rotation of the grinding body encloses an acute angle with a cross-sectional plane of the profile, so that the axis of rotation of the grinding body has a trailing or leading orientation relative to the feed direction of the device relative to the profile.

4. The device as claimed in claim 1, wherein the at least one contact element and the axis of rotation are kinematically coupled with each other such that, during a grinding process, an orientation of the axis of rotation relative to the profile is constant, with a change in an orientation of the axis of rotation relative to the contact element.

5. The device as claimed in claim 1, wherein the axis of rotation is movable about a virtual pivot axis for adjusting the orientation of the axis of rotation relative to the vertical plane and/or relative to the horizontal plane, wherein an instantaneous center of rotation is located on a side of the running surface and/or side surface to be machined grinded off of the profile facing away from the grinding body.

6. The device as claimed in claim 1, wherein the device comprises a plurality of grinding bodies that are movable relative to one another on the support in a same cross-sectional plane of the profile, and the support is configured to be movable relative to the device in the transverse plane for delivery relative to the side surface and/or the running surface.

7. The device as claimed in claim 1, wherein the support is automatically aligned due to an adjustable pretensioning force in the transverse plane relative to the profile and relative to the device.

8. The device as claimed in claim 1, wherein the grinding body can be pretensioned in a force-controlled manner relative to the profile.

9. The device as claimed in claim 1, wherein the axis of rotation of the grinding body is oriented with a lateral offset in a cross-sectional plane of the profile such that the axis of rotation does not intersect the profile.

10. The device as claimed in claim 1, wherein the device comprises a plurality of grinding bodies that are arranged one behind the other on one respective support in the feed direction, wherein the axes of rotation of the plurality of grinding bodies are oriented inclined to one another, and at least one contact element is assigned to each grinding body.

11. The device as claimed in claim 1, wherein, in a cross-sectional plane thereof, the profile has a convex or planar surface divided into a plurality of surface portions to be grinded, wherein the device comprises a plurality of grinding bodies arranged with different inclination angles of respective axes of rotation for machining different surface portions, wherein at least one grinding body has a concave contouring.

12. The device as claimed in claim 1, wherein the orientation of the axis of rotation for trailing or leading machining is inclined relative to a cross-sectional plane of the profile and relative to the feed direction.

13. The device as claimed in claim 1, wherein the at least one grinding body has a concave machining surface on a front face, with a cutting edge that is geometrically undefined.

14. The device as claimed in claim 1, wherein, via a control, a pressing force of the grinding body is adjustable relative to the profile as a function of a torque acting on the axis of rotation and/or a feed rate of the device.

15. The device as claimed in claim 1, wherein, during a rotating and/or oscillating movement of the grinding body, the support is configured to be movable in a reversible translational manner in a plane parallel to a main extent of the profile.

16. The device as claimed in claim 1, wherein the axis of rotation of the at least one grinding body encloses an acute angle with the longitudinal axis of the profile.

17. The device as claimed in claim 1, wherein the at least one grinding body and/or the support is capable of being driven in the rotational manner or the translational manner by at least one electrical and/or hydraulic drive of the device.

18. The device as claimed in claim 1, wherein a rotational or oscillating movement of the at least one grinding body and a translational movement of the support are synchronized by a kinematic coupling.

19. A method for grinding a profile the method comprising:

driving at least one profiled grinding body in a rotational movement and/or oscillating movement about an axis of rotation, and

applying an adjustable pretensioning force on the grinding body against the profile in a force-controlled manner, wherein at least one contact element is aligned as an abutment with the at least one grinding body, in a common plane of a flux of force of reaction forces that act as the profile is being grinded.

20. The method as claimed in claim 19, wherein an orientation of the axis of rotation relative to a vertical plane and/or relative to a horizontal plane of the axis of rotation of the at least one grinding body is changed during the machining of the profile.

21. The method as claimed in claim 19, wherein the grinding of the profile is carried out in a same direction or an opposing direction.

22. The method as claimed in claim 19, wherein the at least one grinding body is arranged on a support, and during the rotational or oscillating movement of the at least one grinding body, the support is driven at least temporarily in a reversing translational manner for introducing a superimposed movement in a plane parallel to a longitudinal axis of the profile.

23. The method as claimed in claim 22, wherein a rotational speed and/or a frequency of the rotational or oscillating movement of the at least one grinding body is changed in a region of reversal points of the reversing translational movement of the support.

24. The method as claimed in claim 19, wherein the at least one grinding body is driven in synchronism at a lower rotational speed or frequency in a direction of travel than counter to the direction of travel, or is driven at a higher rotational speed or frequency in the direction of travel than counter to the direction of travel.

25. The method as claimed in claim 22, wherein the rotational or oscillating movement of the at least one grinding body and the translational movement of the support are kinematically coupled together.

26. The method as claimed in claim 19, wherein material is initially removed on the profile by milling at least in a sub-region of a transverse profile of the profile, wherein the removal is carried out up to an oversize, relative to a reference size, and then the oversize is at least partially removed by grinding.

27. The method as claimed in claim 19, wherein the pretensioning force is adjusted based on measured values of a rotational speed, a feed rate, a pressing force, and/or a torque of the grinding body.