|Title of Invention||
A PROFILE TRANSITION RAIL FOR CONNECTING STANDARD RAILS HAVING DIFFERENT CROSS-SECTIONS AND METHOD FOR PRODUCING THE SAME.
|Abstract||A profile transition rail (1) for connecting standard rails having different rail cross sections (2,3). The transition rail (1) comprises at least two transition zones (a,c), and that in a first profile transition zone (c) the highest cross-section1 profile is reshaped to have a lower height prifile, and in that second profile transition zone (a) disposed downstream,the rail foot is adapted to match the new profile of the adjoining rail foot.|
FIELD OF INVENTION
The invention relates to a transition rail for the connection of rails having different rail cross sections and a method for producing such a transition rail.
BACKGROUND OF INVENTION
In modern railway traffic, increasing axial loads are applied such that load limit ranges of the running track may be readily exceeded. Hight loads will occur in the transition zone particularly in regions or rail portions where the rol1ing load moves from one rail profile to another rail profile. Such transition zones are not only known in switch regions and, in particular, at the transition from standard rails to spring tongues. Asymmetri thick-web rail profiles as are used, for instance, in known spring tongue and spring rai1 switches for railways, must be connected to rail profiles having larger heights. During rehabilitation works on rai1 bodies, it may however also happen that older rai1 profiles will have to be adapted to more 'modern rail profiles, such different rail profiles differing not only in terms of height, but also in regard to the widths of their feet.
Among the known measures for the production of such transition pieces or transition rails, it was, for instance, proposed in DE 828 792 C to reforge asymmetric thick-web rai1 profiles into rail profiles having larger heights, the asymmetric thick-web rail profiles in that known method having been reforged to at least approximately symmetric profiles without any substantial enlargement of the profile height and the profile height having subsequently been obtained by deformation of the web.
Yet, as in DE 33 33 7OO C, the transition piece in that case is formed in manner that the parameters to be changed are being changed substantially all at one time, an adaptation both of the height of the web and of the foot of the rai1 having been effected over the same length of the transition rail piece. A transition from one rail profile to another rail profile over as short a length as possible was to be ensured by the aid of forged fittings.
EP 1 013 826 still also departs from the conviction that a substantially continuous geometric course is to be reached in the zone of transition from one rail profile to another rail profile, appropriate adaptations having to be effected in a connection-side end region.
OBJECT OF THE INVENTION
The invention aims to provide a transition rail of the initially defined kind, by which it is feasible to interconnect rails having different rail cross sections and rail profiles, which allows for even higher wheel loads without local overloading and stress concentration, and which, as a result, is designed to be break-proof to a higher extent than hitherto known transition rails.
SUMMARY OF INVENTION
To solve this object, the transition rail according to the invention is essentially characterized in that the transition rail comprises two transition zones, wherein in a first transition zone the larger-height cross-sectional profile is reshaped to transition into a smaller profile height and in the following, second transition zone having the smaller profile height the rail foot is worked to match the new profile of the consecutive rail foot. As in contrast to the prior art, it is, thus, proposed according to the invention to carry out the required adaptations separately in spatially separated transition zones and merely reduce the profile height in a first partial
region and adapt the rai 1 foot to the new profile only in a spatially separated, further partial region. A reduction of the profile height, as is obtained in a particularly simple manner by upsetting or pressing, naturally results in an increase of other dimensions and, in particulars the width of the foot in this partial region under an appropriate lateral pressing force exerted on the web. Due to the fact that no additional method steps or shape adaptation steps are, at the same time, carried out in such changing partial regions, it has now surprisingly turned out that stress concentrations as observed in configurations in which height and foot width profile changes are effected in the same cross section will no longer occur and that* overall, the breaking resistance of such a transition rail can, therefore, be substantially enhanced even under extreme axial loads. This surprising result could subsequently be verified by a computational model in which a stress determination was appropriately modeled by a finite elements model. In that computational model, the axial force occurring was introduced as a surface pressure, and it could be demonstrated that the stress concentrations clearly observed with known configuration would no longer occur. Between the two partial regions separately adapted to the respectively new geometry, also 3 neutral
intermediate region, i.e. a region of constant cross-sectional
shape, may preferably be provided in order to obtain a further stress concentration reduction between the two deformation zones.
A further preferred configuration will result if the second transition zone, to which the lower profile height has already been imparted and whose rai1 foot has been worked to match the new profile of the consecutive rai1 foot, is arranged closer to the free end of the transition rail than the first transition zone - On the free end of the transition rail, welding with the connector rail having the smaller profile height and the modified rail foot is effected) whereby, due to the fact that the second, merely mechanically worked transition zone is arranged closer to the welding site, stress concentrations as might possibly occur in the first transition zone formed by reshaping will be kept away from the welding site.
The method according to the invention, for producing a transition rai1 of this type is essentially characterized in that the transition rai1 is at first heated and introduced into a press mold, whereupon the rai1 is reshaped in the web region iand pressed in the direction of the profile height, and that the rail foot is mechanically worked following complete reshaping.
By merely effecting pressing in a first method step after heating, it is feasible to deform the transition rail to the desired profile height, wherein, by using a press form, also the web width can be brought to the desired measure, or kept at the desired measure. It is only after such a complete reshaping naturally extending over a defined axial length of the transition rail that the second adaptation is effected, the rail foot being mechanically worked after this. In order so, the rail foot is advantageously machined, thus at the same time enabling the realization of the transition from a wider to a narrower rail
installation into a track will be further simplified and additional welding procedures will no longer affect the region of the transition rail in any manner whatsoever.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
In the following, the invention will be explained in more detail by way of any exemplary embodiment schematically iIlustrated in the accompanying drawings. Therein) Fig. 1 is a side vide of a rail course including an installed transition piece; Fig. 2 is a top view on the illustration according to Fig. 1; Fig. 3 is a section along line III/III of Fig. 1; Fig. 4 is a section along line IV/IV of Fig. 1; and Fig. 5 is a section along line V/V of Fig. 1.
DETAIL DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
In Fig. 1, a transition rai1 is denoted by 1, which, departing from a standard rail profile 2, enables the transition to another rail profile 3. The transition rail 1 is connected by welding with the standard rail having a modified profile height 3 the respective weld being denoted by 4. The transition rai1
region 1 comprises portons a, b and c with portion a having already been pressed to a reduced profile height and worked merely in the rai1 foot region. As is apparent) in particular! from Fig- 2, such working involves machining of the rail foot at a rounding radius r = 120-130. In the configuration according to Figs. 1 and 2, zone b is designed as a substantially neutral region in which the rail foot has not yet been worked in its width but merely adapted in terms of profile height to the new conditions by reforging or pressing. That forging or pressing procedure takes place in the first transition-rail partial region c adjacent to the standard rai1 2, with pressing forces being at the same time applied in the height direction and traverse to the web, as is particularly apparent from the cross sections according to Figs. 3, 4 and 5.
Fig. 3 depicts the final connection profile having the modified rail height and the modified web width corresponding to rail portion 3. This profile shape corresponding to the section according to 1ine III/III of Fig. 1, thus, corresponds with the profile capable of being welded with the transition rail, The cut IV/IV illustrated in Fig- 4 was laid in the region of the transi tion rail itself. From this i1 lustration it is apparent
that merely the rail foot is different from its desired width and consequently still needs to be machined to the desired width. The initial profile corresponding to rail 2 is characterized by substantially wider rail webs and a larger profile height. This initial profile corresponds to the section along 1ine V/V and is apparent from Fig. 5, When comparing the profiles according to Figs. 3, 4, and 5, it is immediately apparent that the head profile in the region of the transition rai1 and between the two interconnected rails is not modified at all. The web has become slightly narrower at the transition from rail 2 to rail 3, from which it can be taken that? in the context of the deformation of the rail having the profile according to Fig. 5 into a rail having the profile according to Fig. 4, not only forces acting in the height direction to upset the profile height, but also lateral pressing forces were at the same time applied in order to appropriately delimit the web width. In such a deformation step, the region of the rail foot naturally changes and the final working of the rail foot is effected in a partial region of the length of the transition rail, in which partial region the deformation by forging, or deformation by pressing, has already been completed, and consecutive to such a partial region.
1. A profile transition rail (1) for connecting standard rails having airterent rail cross sections (2,3), characterized in that the transition rail (1) comprises at least two transition zones (a, c) , and that in a first profile transition zone (c) the highest cross-sectional profile is reshaped to have a lower height profile. and in that second profile transition zone (a) disposed downstream, the rai1 foot is adapted to match the new profile of the adjoining rail foot.
2. A profile transition rail as claimed in claim 1, wherein the second transition zone (a) is arranged closer to the free end of the transition rail (1) than the first transition zone (c).
3. A profile transition rail as claimed in claim 1 or 2, wherein a zone (b) of constant cross-sectional shape is arranged between the first transition zone (c ) and the second transition zone (a).
4. A method for producing a profile transition rail as claimed in claim 1, 2 or 3 characterized by comprising the steps of heating the transition rail first and introducing into a press mold, thereby reshaping the rai1 in the web region; press-moulding the rail in the direction of profile height; and mechanically working the rail foot to achieve the final reshaping of the rail.
5. A method as claimed in claim 4, wherein mechanically working the rail foot comprises machining of the rail foot.
6. A method as claimed in claim 4 or 5, wherein the second transition zone (a) of the rail foot, in which the width of the rail foot decreases, is configured to have a round shape when viewed from the top.
A profile transition rail (1) for connecting standard rails having different rail cross sections (2,3). The transition rail (1) comprises at least two transition zones (a,c), and that in a first profile transition zone (c) the highest cross-section1 profile is reshaped to have a lower height prifile, and in that second profile transition zone (a) disposed downstream,the rail
foot is adapted to match the new profile of the adjoining rail foot.
|Indian Patent Application Number||01631/KOLNP/2004|
|PG Journal Number||37/2007|
|Date of Filing||02-Nov-2004|
|Name of Patentee||VAE EISENBAHNSYSTEME GMBH|
|Applicant Address||ALPINESTRASSE 1, A-8740 ZELTWEG,AUSTRIA|
|PCT International Classification Number||B21K7/02|
|PCT International Application Number||PCT/AT03/00099|
|PCT International Filing date||2003-04-04|