EP3102737A1

EP3102737A1 - Single-piece cast steel frog for a railway crossing

Info

Publication number: EP3102737A1
Application number: EP15709983.9A
Authority: EP
Inventors: Ferenc Schmidt
Original assignee: Palya-Szintvonal Tervezo Es Szolgaltato Ktf
Current assignee: Palya-Szintvonal Tervezo Es Szolgaltato Ktf
Priority date: 2014-02-03
Filing date: 2015-01-21
Publication date: 2016-12-14
Anticipated expiration: 2035-01-21
Also published as: EP3102737B1; HUP1400048A2; WO2015114394A1; HUE045633T2; HRP20191537T1

Abstract

The subject of the invention relates to a common crossing assembly used for (traditional) wooden sleeper railway switches, where the maximum speed of railway vehicles passing through the switch in the straight direction is 120 km/h and the maximum speed in the switched direction is 40 km/h, which has wing rails, a crossing frog and fork rails and which structural parts are fixed to each other from underneath with a base plate, and flangeways run between the crossing frog and the side surfaces of the wing rails for guiding the wheels of the railway vehicle. The essence of the invention is that the common crossing assembly is established as a single member, as a cast steel piece.

Description

SINGLE-PIECE CAST STEEL FROG FOR A RAILWAY CROSSING

The subject of the invention relates to a common crossing assembly a railway switch, which has wing rails, a crossing frog, and fork rails, which structural components are fixed to one another from below with a base plate, and flangeways run between the crossing frog and the wing rails to guide the wheels of the railway vehicle.

It is known that switches are viewed as the most dangerous parts of railways from the point of view of the operation of the railway line, one of the main components of which is the common crossing assembly, which as a result of its structure and structural dimensions it demands regular monitoring and maintenance due to the rapid rate of wear.

Over the past decades significant developments and modernisations have taken place in the field of concrete sleeper, high-speed switch structures, as a consequence of the line reconstruction process of the European corridor passing through Hungary, however, the majority of the domestic and branch lines continue to use traditional, wooden-sleeper superstructure structures, even though a significant proportion of passenger traffic and a very large proportion of freight traffic takes place on these lines. In the case of these lines according to the relevant regulations the maximum speed of railway vehicles passing through a switch in the straight direction is 120 km/h and the maximum speed in the switched direction is 40 km/h.

Ensuring and maintaining the appropriate technical condition of common crossing assemblies, although they have a classification with a decisive effect on transport safety, represents a serious task.

The main components of common crossing assemblies are the wing rail, the crossing frog and the fork rail. In the 1960s in Hungary the crossing frogs of the aforementioned traditional, wooden sleeper railway switches were made as a single unit from cast iron, while the associated wing rails and fork rails, coupled with various connection elements, were assembled with horizontal bolt connections into a common crossing assembly. In the case of this solution the beginning of the crossing frog comes to an end in a vertical plane, before it there is a facing point lock bolt connection. Between the front of the crossing frog and the wing rail profile there is an air gap, and outside of the crossing frog, the wing rail is shaped for the given task by work-shaping the standard track rail. The disadvantage of this solution is that it consists of many components, certain items of which may move separately due to the - not excluded - loosening of the bolt connections on the effect of the load, therefore, the wearing and deterioration process is accelerated. It is also a disadvantage that the fork rails are only connected to the crossing frog with a "tight" fit.

From the second half of the 1970s - mainly due to reasons of economy - instead of being cast the crossing frogs of traditional, wooden sleeper railway switches were made from three material parts and were fitted together into a unit, a crossing frog, by planing. The front of the crossing frog in this case also ends in a vertical plane, with a facing point lock bolt connection in front of it, and between the front of the crossing frog and the wing rail profile there is an air gap. Both the crossing frog and the wing rail are formed by work-shaping the standard track rail.

In the case of this solution it is a disadvantage that the crossing frog itself consists of several components, and demands many horizontal bolt connections, which if loosened the individual components will separately move due to the effect of the load. Therefore, the processes of wearing and hammering accelerate. The structure has a great demand for monitoring and maintenance.

The task to be solved with the invention is to provide a railway common crossing assembly fundamentally for the traditional, wooden sleeper switches presented above which is significantly less demanding in terms of monitoring and maintenance as compared to the known solutions with a similar function, through which the required level of operation reliability may be maintained with a smaller investment of time and money and the lifetime of which also exceeds the lifetime of the presently used, traditional, wooden sleeper railway common crossing assemblies.

The invention is based on the following recognitions.

When setting up the second of the solutions discussed above, they started from the - incorrect from out point of view - assumption that the reason it is advantageous to establish the common crossing assembly, and, within this, the crossing frog also from several components that may be disassembled is that only those components have to be replaced that suffer wear or damage. During use, however, it has been proven that wear characteristically appears jointly in the crossing frog - as well as in all of its sub-components - and in the wing rails, due to which there is no reason for it to be possible to disassemble the structural assembly and to replace its elements.

We recognised that by applying the appropriate geometric characteristics the common crossing assembly of railway switches may be established as a single metal cast piece, in other words as a single cast switch common crossing assembly, which requires less monitoring and maintenance and is less sensitive to wear, provides greater safety with respect to track-vehicle interaction, is simpler to maintain, and has lower operation costs than the presently known and used structures with this function.

On the basis of the above recognitions we solved the set task with a common crossing assembly used for railway switches which has wing rails, a crossing frog and fork rails and which structural parts are fixed to each other from underneath with a base plate, and flangeways run between the crossing frog and the side surfaces of the wing rails for guiding the wheels of the railway vehicle and the essence of which railway common crossing assembly is that the common crossing assembly is established as a single member, as a cast steel piece.

According to an advantageous embodiment the wing rails have rear end portions angled outwards with respect to the travelling direction of the vehicle from the front of the switch. It is preferable if the end sections of the flangeways have an outwardly expanding cross-section in the range of these end portions.

According to another invention feature the base plate has a reinforced portion - preferably thickened - in the vicinity of the end portions of the wing rails, and along the end portions transfer surfaces are formed in the end sections of the flangeways that are sloped at an angle from above downwards starting from the base plate. It is preferable if at the location where the fork rails start from the crossing frog, the base plate links the fork rails to each other and to the crossing frog, and here a transfer surface is formed that is sloped at an angle from above downwards.

According to a further embodiment before the crossing frog with respect to the direction of travel of the vehicle it is preferable if the base plate liriking the wing rails to the crossing frog has a horizontal or substantially horizontal surface in the "unguided" section of the flangeways in the range extending to the break line of the wing rails, and starting from this surface a transfer surface is formed that is sloped at an angle from below upwards that extends to the vicinity of the point of the crossing frog.

That embodiment of the common crossing assembly is preferable in the case of which in the "unguided" section of the flangeways there are reinforcing members on the external sides of the wing rails delimiting this section made by thickening them. It is also preferable if gaps are formed in the base plate running longitudinally in the interest of making the common crossing assembly lighter.

It is characteristic of another embodiment that the transfer surface extending to the vicinity of the point of the crossing frog is established from two sections of differing lengths and at different angles to the horizontal, which connect to each other with a rounded shoulder part, and the front section is at an angle of between 28°-36°, preferably between 30°-33° to the horizontal, and the second section extending to the shoulder is horizontal or essentially horizontal; and the ratio of the length of the front section as compared to the length of the rear section is approximately 1 : 6, preferably 1 : 5.2. Preferably the angle of inclination of the sloped transfer surface established at the point where the fork rails start from the crossing frog with respect to the horizontal is between 115° and 125°, preferably about 120°, and it is also preferable if the sloped transfer surfaces established at the end sections of the flangeways are at an angle of between 25° and 30° to the horizontal. It is also preferable if the lightening gaps preferably getting wider in the downwards direction essentially run along the entire length of the base plate; their depth changes in a way that follows the surface of the common crossing assembly, and the volumes in the lightened cross-sections are preferably the same, their ratio preferably varies between a maximum of about 10-40%.

The railway switch common crossing assembly established as a steel cast piece according to the invention is especially suitable for installation in traditional, wooden sleeper switches in Hungarian railway networks with a 48. r. superstructure.

In the following the invention is presented in more detail on the basis of the attached drawings, which contain a preferable embodiment of the common crossing assembly. In the drawings

Figure 1 shows the top view of an embodiment of a common crossing assembly;

Figure 2 shows a perspective view of the common crossing assembly according to figure 1;

Figure 3 shows a larger-scale rear view from the direction of the arrow A marked in figure 2;

Figure 4 shows a larger-scale front view from the direction of the arrow B marked in figure 2;

Figure 5 shows a larger-scale top view of a middle section of the common crossing assembly;

Figure 6 shows a larger-scale perspective view of detail C of the common crossing assembly marked on figure 1, viewed at an angle from above; Figures 7-11 show the cross-sections taken along lines D-D, E-E, F-F, G-G and

H-H marked in figure 1 in a larger scale;

Figure 12 shows the front part of the common crossing assembly in bottom view;

Figure 13 shows the middle part of the common crossing assembly in bottom view;

Figure 14 shows the rear part of the common crossing assembly in bottom view.

The embodiment of the common crossing assembly cast as a single piece according to the invention in figures 1 and 2 has wing rails la, lb and fork rails 4a, 4b, and also a crossing frog 2 ending in a point 3. The wing rails, the fork rails and the crossing frog are connected together into a unit from below by the base plate 5, in other words the railway common crossing assembly according to the invention is created as a single steel casting. It is noted that the base plate 5 may be viewed as an extended part of the rail bases marked with reference number 12 in figures 1 and 2, and runs as a kind of continuation of them, and performs the same task as their load distribution function (the base plate 5 is in a obscured position in figure 2, it is not visible). In the longitudinal direction the base plate 5 extends to the length marked in figure 1 with reference letter b of the common crossing assembly. In figures 1 and 2 the rail web is marked with reference number 13 and the rail head with reference number 14.

The flangeways 6a, 6b run between the longitudinal side surfaces of the crossing frog 2 and the internal surfaces of the wing rails la, lb, which are delimited underneath by the base plate 5.

In the present specification from the point of view of the point 3 of the crossing frog 2 the wing rail la diverts the train passing over the common crossing assembly to the left direction and the wing rail lb diverts it to the right direction, the direction of travel of which is marked with arrow a in figures 1 and 2.

The wing rails la, lb have turned out end portions la', lb'. As it can be clearly seen in figures 1 and 2 the crossing frog 2 widens starting from the point 3 in the direction of the arrow a, therefore, viewed from above it is essentially a triangular shaped part of the common crossing assembly, and at its widened end opposite the point 3 it branches out into the left side fork rail 4a and the right side fork rail 4b, in other words the fork rails 4a, 4b start out from the crossing frog 2.

In figures 1 and 2 the section 15 of the common crossing assembly has been marked with the reference letter c in which the wheels of the railway vehicle (not shown) are not guided - in the specialist field this is called the "unguided" section - therefore, this section 15, in the way illustrated in figures 2, 3 and 5 is thickened with reinforcing members 10a, 10b and 10a', 10b', in other words reinforced, which obviously belong to the crossing assembly established as a casting, made with this as a single member - cast as a single piece - and are "built onto" the outer side of the wing rails la, lb. So at these places there are thickened - reinforced - parts as a continuation of the front and rear end of the middle parts 10c and lOd with respect to the direction of travel a of the vehicle, in other words in the incoming and outgoing sections, which is illustrated especially well in figure 2. The cross-section of the middle parts 10c, lOd is the same as the cross-section of a normal rail.

These reinforcing members 10a-10b' are needed because while in motion due to the lateral deviations of the vehicle wheels a lateral, dynamic extra load is exerted on the common crossing assembly also in the otherwise very short "unguided" section 15, more precisely on the inner surfaces of the wing rails la, lb. We recognised that in the case of the known and currently used common crossing assemblies, as a result of the track-rail profile running through the "unguided" section, this section is much more prone to deformation, faults and breakages than the other sections of the common crossing assembly.

We recognised that if the common crossing assembly is made from a single steel casting, these risks may be overcome by thickening the rail section, in other words with the reinforcing members 10a, 10b cast with these rails. The use of thickening elements fixed to the rail profile with rivets would be an uncertain solution, they would not be capable of filling the reinforcing function.

In the larger-scale figures 3 and 5 it is also clearly visible that the reinforcing members 10a, 10b reinforce this "unguided" section 15 of the casting, namely the "side walls" delimiting this section 15 of the wing rails la, lb, which the vehicle wheels impact as a consequence of the lateral deviations / snake-like motion of the vehicle wheels. Therefore, the "unguided" section 15 of the wing rails la, lb is a reinforced section that prevents, or at least minimises, the disadvantageous consequences of the supplementary dynamic effects deriving from the snake-like motion of the vehicle wheels.

In figure 3 the common crossing assembly according to the invention may be seen in larger scale, in perspective view viewed from the direction of the arrow A marked in figure 2, in this figure the other presented structural elements have been indicated with the reference numbers already used.

In figure 3 it can be easily seen that at that place where the fork rails 4a, 4b protrude from the crossing frog 2 in the direction of the arrow a indicating the direction of motion of the train, in other words at the place where the crossing frog 2 and the fork rails 4a, 4b meet, a multiply-rounded inclined transfer surface 7 is established between the rear end of the crossing frog 2 and the fork rails 4a, 4b, which slopes downwards from above and runs out to the base plate 5. In figure 3 the rounded parts are indicated with the reference number 7a. The inclined transfer surface 7 passes though these rounded parts 7a from the base plate 5, or from the rail base 12 of the fork rails 4a, 4b to the crossing frog 2. It is to be noted that it is preferable to avoid sharp / pointed parts everywhere on the casting, this is why the shoulder 8c marked in figure 5 with reference number 8c, to be presented in detail later, is also rounded.

The base plate 5, the length of which is indicated in figure 1 with reference letter b, and only a small part of which is visible in figure 3, extends from the rear end of the wing rails la, lb until that part of their front end where the wing rails go U2015/000002

9 over to normal rail profile. The base plate 5 links the initial section of the fork rails 4a, 4b into a rigid unit, the significance of which is made especially obvious by the fact that in the case of solutions belonging to the state of the art in this structural junction point the two fork rails are able to each move separately due to the wear and the loose bolt connections, which naturally leads to the reduction of the lifetime of these two structural parts and results in the risk of faults occurring.

In figure 3 the flangeways - i.e. the left side and right side flangeway - indicated with reference numbers 6a, 6b in figures 1 and 2 are shown in larger scale, in more detail, which run between the inner surface of the wing rails la, lb and the side surfaces of the crossing frog 2, and their function is to guide the flange of the vehicle wheel (not shown).

In figures 3 and 6 it is well illustrated that the folded out - rear - end parts la', lb' of the wing rails la, lb are formed by the sloped outwardly protruding ends of the wing rails themselves. This inclined folding outwards results in the extension and widening of the end sections of the flangeways 6a, 6b. An inclined transitional plane indicated in figure 6 with reference number 11 - otherwise called a guiding in or guiding out plane - runs in the casting structure in the length of the folded out end parts la', lb', which is, accordingly, is linked to the reinforced base plate 5. In figure 6, where the structural elements already presented have been marked with the reference numbers already used, it can be easily seen that that part of the base plate 5, from where the transfer surfaces 11a, lib inclined in the direction from below upwards start, is thickened; this thickened or reinforced base plate part is marked with reference number 5'.

According to the above at the ends of the fork rails 4a, 4b the parallel nature of the wing rails la, lb is "pushed out" as compared to the previous when receding from the wing rails, and the height of the flangeways 6a, 6b is led to the height of the base plate 5 with an inclined transfer surface. Therefore at the "divergence" of the fork rail and the wing rail the sloped transfer surfaces 11a, lib inclined from below upwards bridge over the height difference between the two levels. It is noted that in the case of the known and currently used such common crossing assemblies the wing rail folding out was established by using the standard track rail - by bending it out - and by longitudinally working the rail head, therefore at the bending out due to the structural material the structure is "airy"; the disadvantages involved with this were presented earlier. It is noted that this traditional establishment of the wing rails also determines that the "unguided" section has a disadvantageous structure, and we have overcome this disadvantage - as detailed above - according to the invention by reinforcing the cross-section dimension of the "unguided" section.

In figures 4 and 5 we have shown the railway common crossing assembly according to the invention in a view from the point 3 and in top view, the reference numbers and symbols already used have been accordingly used in these figures for the marking of the same structural parts. In these figures it can be seen that in front of the crossing frog 2, up to the vicinity of the break line of the wing rails la, lb shown on figures 1 and 2 and marked with reference numbers 16a, 16b, in other words from where their folded out end parts la', lb' start, surface 5' of the base plate 5 of the casting is horizontal and here the base plate 5 links up the wing rails la, lb to the crossing frog 2 in the "unguided" section 15 of the base plate 5 without bolt connections into a integral unit, with this increasing the frame rigidity of this junction point. Ain the case of the known and currently used common crossing assemblies the fixing takes place in front of the crossing frog with facing point lock bolt connections; there is an air gap between the front of the crossing frog and the profile of the wing rails; and for this junction point the crossing frog and the wing rail, and the wing rail outside of the crossing frog were formed by working the standard track rail.

Starting from the inner end of the horizontal or essentially horizontal surface 5' of the base plate 5, from the break point 17, an inclined, long transfer surface 8 sloping from below upwards is established (see fig. 1 also), which extends until the widening base part 3b of the point 3 with a vertical web 3a of the crossing frog 2. The inclined transfer surface 8 is formed from two sections with different angles of inclination, a shorter lower section 8a and a longer upper section 8b, and where these sections 8a, 8b go into one another a rounded shoulder 8c is formed. The front section 8a is at about 30°-35° to the horizontal, preferably at about 30-33°, and the rear section 8b is horizontal, or essentially horizontal up until the start of the crossing frog; and the length of the section 8a is about 1/8-1/7* of the length of section 8b, preferably about 1/6* of its length. In a concrete case, for example, the length of section 8a is approx. 130 mm, its height 82 mm and its angle of inclination 31°; the length of the rounded shoulder 8c is approx. 50 mm; and the length of the rear section 8b may be, for example, approx. 650 m, and this section 8b extending until the shoulder 8c is horizontal or essentially horizontal. The essentially three-sectioned planar transfer surface 8 leads the crossing frog 2 to the base plate 5. In the case of the currently known and used wooden sleeper switches and common crossing assemblies, the rail bases of the wing rails are linked to each other via horizontal bolt connections, which makes the connection fragile and shortens the expected lifetime.

The inclined transfer surfaces 7, 8, 11a and lib presented above prevent, or at least significantly reduce the damage that may occur when railway wagons pass over the common crossing assembly. This damage may be due to that the train set wagons are linked to each other - in a known way - with screw coupling, in other words with a threaded pin, which - when the railway wagon break apart from each other - get broken and hang down to the rail top level, and even under this level. The hanging screw coupling, while the railway wagon is moving, gets caught in the protruding parts of the components of the railway line, and exerts an impact effect on them. The switches, and within these the common crossing assemblies, obviously contain such protruding parts, and the hanging and quickly moving screw couplings hitting them may damage and even destroy them.

If the common crossing assembly is formed by a casting, it is very simple to do away with protruding parts, namely by establishing planar, inclined transfer surfaces 7, 8, 11a, lib, and rounded shoulders, over which the aforementioned broken off, hanging coupling screw slides over while the railway wagon is moving without getting caught in anything, therefore it cannot break or damage the common crossing assembly according to the invention.

As it can be seen in figures 7-14, the common coupling assembly according to the invention and cast as a single unit is a lightened structure, as the unbroken gaps 18 and 19 run in the base plate 5, along its entire length b indicated in figure 1, the longitudinal path of which may be seen in figures 12-14 and their cross-sectional shape may be studied in figures 7-10. The gaps 18, 19 have a cross-section that expands from the top downwards, their greatest width s and height m along their total length varies depending on the loads exerted, and on the consideration whether the solid parts of the casting should have relatively equal volumes, due to the better casting characteristics of these. It is preferable if the ratio of solid and hollow parts under the rail head varies between a maximum of 10-40%. Due to the solving of the lightening with such gaps 18, 19, the structural parts in the common crossing assembly according to the invention have similar characteristics, the flexibility of the entire common crossing assembly significantly exceeds the flexibility of the known such common crossing assemblies and require minimal use of materials. In the case of the known and used traditional solutions the structural elements fitted together and planed from track rail are connected with bolt connections, there is practically no possibility for lightening, the component units bear the form and shape of the given track rail part on themselves. The rail cross-section inertia value cannot be changed in the case of the previous solutions.

The advantageous effects linked to the invention are as follows:

a fundamentally important advantage of the common crossing assembly according to the invention that may be used primarily for traditional wooden sleeper railway switches is that it is significantly less sensitive to maintenance than the traditional common crossing assemblies assembled from individual elements using bolt connections, its lifetime is longer than these, and, at the same time, it geometrically complies with the characteristic features of these. In the case of replacing components of switches in railway lines the common crossing assembly according to the invention is compatible, it is less sensitive to wear, its maintenance is simpler, and its operation costs are lower than in the case of traditional such structures.

Naturally the invention is not limited to the embodiment detailed above, it may be realised in several different ways within the sphere of protection defined by the claims.

Claims

1. Common crossing assembly used for (traditional) wooden sleeper railway switches, where the maximum speed of railway vehicles passing through the switch in the straight direction is 120 km/h and the maximum speed in the switched direction is 40 km/h, which has wing rails, a crossing frog and fork rails and which structural parts are fixed to each other from underneath with a base plate, and flangeways run between the crossing frog and the side surfaces of the wing rails for guiding the wheels of the railway vehicle, characterised by that the common crossing assembly is established as a single member, as a cast steel piece.

2. The common crossing assembly according to claim 1, characterised by that the wing rails (la, lb) have rear end portions (la', lb') angled outwards with respect to the travelling direction (a) of the vehicle and in the range of these end portions (la', lb') the end sections of the flangeways (6a, 6b) have an outwardly expanding cross-section.

3. The common crossing assembly according to claim 1, characterised by that the base plate (5) has a reinforced portion - preferably thickened - in the vicinity of the end portions (la', lb') of the wing rails (la, lb), and along the end portions (la', lb') transfer surfaces (11a, lib) are formed in the end sections of the flangeways (6a, 6b) that are sloped at an angle from above downwards starting from the base plate (5)·

4. The common crossing assembly according to any of claims 1-3, characterised by that at the location where the fork rails (4a, 4b) start from the crossing frog (2), the base plate (5) links the fork rails (4a, 4b) to each other and to the crossing frog (2), and here a transfer surface (7) is formed that is sloped at an angle from above downwards.

5. The common crossing assembly according to any of claims 1-4, characterised by that before the crossing frog (2) with respect to the direction of travel (a) of the vehicle it is preferable if the base plate (5) linking the wing rails (la, lb) to the crossing frog (2) has a horizontal or substantially horizontal surface (5a) in the "unguided" section (15) of the flangeways (6a, 6b) in the range extending to the break line (17) of the wing rails (la, lb), and starting from this surface (5a) a transfer surface (8) is formed that is sloped at an angle from below upwards that extends to the vicinity of the point (3) of the crossing frog (2), and in the "unguided" section (15) of the flangeways (6a, 6b) there are reinforcing members (10a, 10b) on the external side of the wing rails (la, lb) delimiting this section (15) made by thickening them.

6. The common crossing assembly according to any of claims 1-5, characterised by that gaps (18, 19) are formed in the base plate (5) running longitudinally in the interest of making the common crossing assembly lighter.

7. The common crossing assembly according to any of claims 1-6, characterised by that the transfer surface (8) extending to the vicinity of the point (3) of the crossing frog (2) is established from two sections (8a, 8b) of differing lengths and at different angles to the horizontal, which connect to each other with a rounded shoulder part (8c), and the front section (8a) is at an angle of between 28°-36°, preferably between 30°-33° to the horizontal, and the second section (8b) extending to the shoulder (8c) is horizontal or essentially horizontal; and the ratio of the length of the front section (8a) as compared to the length of the rear section (8b) is approximately 1 : 6, preferably 1 : 5.2.

8. The common crossing assembly according to any of claims 1-7, characterised by that the angle of inclination of the sloped transfer surface (7) established at the point where the fork rails (4a, 4b) start from the crossing frog (2) with respect to the horizontal is between 115° and 125°, preferably about 120°.

9. The common crossing assembly according to any of claims 1-8, characterised by that the sloped transfer surfaces (11a, lib) established at the end sections of the flangeways (6a, 6b) are at an angle of between 25° and 30° to the horizontal.

10. The common crossing assembly according to any of claims 1-9, characterised by that the lightening gaps (18, 19) preferably getting wider in the downwards direction essentially run along the entire length (b) of the base plate (5); their depth (m) changes in a way that follows the surface of the common crossing assembly, and the volumes in the lightened cross-sections are preferably the same, their ratio preferably varies between a maximum of about 10-40%.

The representative: