CA2541132C

CA2541132C - A method of removing damaged rail sections of a track, and a machine

Info

Publication number: CA2541132C
Application number: CA002541132A
Authority: CA
Inventors: Josef Theurer; Bernhard Lichtberger
Original assignee: Franz Plasser Bahnbaumaschinen Industrie GmbH
Current assignee: Franz Plasser Bahnbaumaschinen Industrie GmbH
Priority date: 2005-03-30
Filing date: 2006-03-28
Publication date: 2009-12-15
Anticipated expiration: 2026-03-28
Also published as: CA2541132A1; AU2006201318B8; JP5054322B2; AT501272B8; AT501272B1; CN1840780A; JP2006283553A; CN100564677C; RU2298610C1; AT501272A4; AU2006201318B2; UA87824C2; AU2006201318A1

Abstract

In a method of efficiently removing a great number of damaged rail sections, after a first separating cut, both rail ends are gripped by means of a rail pulling device (20) connecting the rail ends to one another, and are pulled towards one another. The pulling force required for the pulling-together as well an actual rail temperature are registered for calculation of that length of a replacement rail (14) which is required for producing a desired rail tension. A second separating cut is carried out - with corresponding path measurement - spaced at a distance from the first separating cut as calculated on the basis of the selected length of the replacement rail (14).

Description

A METHOD OF REMOVING DAMAGED RAIL SECTIONS
OF A TRACK, AND A MACHINE.
[0001] The invention relates to a method of removing damaged rail sections from welded rails of a track having an actual rail tension and an actual rail temperature, in which, after two separating cuts - with formation of a rail gap and two rail ends - a replacement rail is welded to the two rail ends.
The invention also relates to a machine for preparation of a rail weld.

[0002] Numerous methods or devices for welding rail ends together are already known from US 4 929 816, GB 0 326 794, US 4 983 801 and US 6 515 249.

[0003] From US 5 469 791, it is known to transport rails to the installation site by means of a special machine. A rail pulling device and a welding unit are furnished by a second and third machine.

[0004] It is the object of the present invention to provide a method of the specified kind with which it is possible to execute in an efficient manner also a greater number of welds for achieving a desired rail tension.

[0005] According to the invention, this object is achieved with a method of the specified kind wherein: after the first separating cut, both rail ends are gripped by means of a rail pulling device connecting said rail ends to one another, and are pulled towards one another with application of a pulling force f for eliminating the rail gap; in doing so, the pulling force f required for pulling the rail ends together as well as an actual rail temperature are registered for calculation of that length of a replacement rail which is required for producing a desired rail tension after both sides of the replacement rail have been welded to both rail ends; and the second separating cut is executed, with corresponding path measurement, spaced at a distance from the first separating cut as calculated on the basis of the selected length of the replacement rail.

[0006] With these features of the method, it is possible to determine a difference between an actual rail tension and a desired rail tension in connection with a removal of a damaged rail section. Taking into account the found difference, it is possible to accurately establish the required length of the rail section to be removed in accordance with the length of the replacement section. The prepared replacement rail of accurate length enables a quick execution of the two required welding operations, achieving a desired rail tension. In an advantageous manner, both the removal of the damaged rail sections and the providing of replacement rails of accurately defined length can take place entirely independent of the welding process. With this, it is possible to carry out with optimal efficiency both the welding preparation and the welding itself.

[0007] A further object of the present invention lies also in creating a machine for preparation of a rail weld, with which, while achieving a particularly high working performance, an optimal preparation for producing a high-grade weld with a desired rail tension is possible.

[0008] This object is achieved with a machine comprising a machine frame, mobile on on-track undercarriages, for preparation of a rail weld, having: a rail storage facility for storing a number of replacement rails; a crane jib, vertically adjustable and rotatable by drives, for gripping and unloading a replacement rail; a vertically adjustable rail cutting saw which is adjustably mounted on a saw guide extending in the longitudinal direction of the machine; a rail pulling device mounted on the machine frame for adjustment by means of drives and having two pairs, spaced from one another, of rail clamps designed for gripping and pulling together two rail ends; and a pair, arranged in immediate proximity to an on-track undercarriage, of lifting rams fastened to the machine frame and designed to be lowered for placement upon a track, the lifting rams being provided for lifting the adjacent on-track undercarriage from the track.

[0009] With the aid of the rail pulling device, it is possible to make use of the resulting rail gap for precise determination of a difference between an actual rail tension and the desired value thereof. A machine equipped with the features according to the invention thus makes it possible to provide a replacement rail of precisely established length, with which a desired rail tension can be achieved automatically by ultimately welding it to the two rail ends. In order to obtain the exact length of the damaged rail section to be removed, the rail cutting saw, mounted for displacement along a guide, is of particular advantage. This also enables the creation of cutting surfaces extending exactly parallel to one another on both rail ends, in order to finally obtain a weld of optimal quality with the welding of the replacement section.

[0010] Additional advantages of the invention become apparent from the further claims and the description of the drawing.

[0011] The invention will be described in more detail below with reference to an embodiment represented in the drawing in which [0012] Fig. 1 is a side view of a machine arrangement for preparation of a rail weld, [0013] Fig. 2 is a top view of a rail pulling device for pulling two rail ends together, and [0014] Figs. 3 to 15 are respective schematic side views of the machine arrangement during various stages of the method.

[0015] A machine arrangement 1, visible in Fig. 1, is composed of a first machine 2, a second machine 4 detachably connected to the former by means of a coupling 3, and a third machine 5 designed to be transported by the second machine 4 during transfer travel. Each of said machines 2,4,5 comprises a machine frame 8 mobile by means of on-track undercarriages 6 on a track 7, and each is equipped with a motive drive 9.

[0016] The first machine 2 comprises a rail storage facility 13 located between a driver's cabin 10 and a crane jib 12, the latter being vertically adjustable and rotatable by drives 11. The rail storage facility 13 is configured for transporting and storing a number of replacement rails 14 of different length. Provided underneath the machine frame 8, between the two on-track undercarriages 6 placed at the ends, is a saw guide 16 extending in a longitudinal direction 15 of the machine, on which a rail cutting saw 17 is mounted for displacement by means of a drive 18. A path travelled due to the displacement of the rail cutting saw 17 is registered by an odometer 41. Connected to the machine frame 8 in immediate proximity to each on-track undercarriage 6 is a respective pair 21 of lifting rams 22 which can be lowered upon the track 7 by means of a drive 23.

[0017] A rail pulling device 20, fastened to the machine frame 8 for vertical adjustment by drives 19, is designed for gripping two rail ends 24 of a rail 25 of the track 7 (see Fig. 2). Devices 26 are provided for driving or pulling rail spikes. A vertically adjustable grinding device 27 serves for grinding rail web portions.

[0018] The second machine 4 is equipped With a vertically adjustable device 28 for detaching rail anchors, and a rotatable roller 29 for detaching base plates adhering to the rail 25. Provided in front of the front on-track undercarriage 6 is a vertically adjustable transport device 30 by which the third machine 5 can be transported on the way to the track construction site. Said third machine 5 is also equipped with a device 28 for detaching rail anchors.

[0019] The rail pulling device 20, shown in more detail in Fig. 2, comprises two pairs 31 of rail clamps 32 designed for gripping the two rail ends 24, the pairs being spaced from one another in the longitudinal direction 15 of the machine. The rail ends 24 can be pulled towards one another by actuation of two drives 33. A force f required to do so can be registered by means of a force measuring device 34. A temperature measuring device 35 is provided for detecting an actual rail temperature. Said device, as well as the force measuring device 34, is connected via lines 36 to a control- and computing unit 38 having a storage medium 37. Stored in the storage medium 37 are the various lengths of the replacement rails 14, kept in stock on the rail storage facility 13, and also a respective identification feature. An odometer 40 is provided for measuring a rail gap 39 defined by the distance of the two rail ends 24 to one another.

[0020] The method of removing damaged rail sections 42 and of welding preparation will now be described in more detail in connection with the further Figs. 3 to 15, wherein a dash-and-dot line indicates the local installation site 43 in the track 7, remaining unchanged in Figs. 3 to 15 and defined by the rail section 42 to be removed.

[0021] The machine arrangement 1 is moved in the direction represented by an arrow 44 and stopped in front of the installation site 43 (see Fig. 3). After setting the third machine 5 down upon the track 7 (Fig. 4), the sleeper anchors - lying to the left of the installation site 43 in the drawing - are detached with the aid of the device 28 until the machine 5 has reached an end position visible in Fig. 5.

[0022] Parallel to this, the second machine 4 is moved in the direction towards the installation site 43, during which the sleeper anchors - positioned to the right of the installation site 43 in the picture plane - are detached by means of the corresponding device 28 (Fig. 6). The length of those rail portions in which the rail anchors are detached is registered by an odometer wheel and transmitted by radio to the control- and computing unit 38. In the region of said rail portions, the rail spikes are also removed or loosened. With the aid of the lowered roller 29, the base plates are detached from the rail base of the rails which are lifted slightly from the sleepers.

[0023] The first machine 2 is moved to the installation site 43, and that point on the rail 25 is marked on which a first separating cut is to take place (Fig.
7).

[0024] In further sequence, as shown in Fig. 8, the rail cutting saw 17 is positioned above the marked point , and the first separating cut is carried out, resulting in the two rail ends 21 being spaced from one another, thus forming a rail gap 39 (see Fig. 2). Rotatable wire brushes 45 mounted displaceably on the machine frame 8 are pressed against a rail web of the two rail ends 24 in order to optimize the contact points intended for the welding unit. An on-track undercarriage 6 positioned at one end of the first machine 2 is raised slightly from the track 7 by lowering the associated lifting rams 22.

[0025] The rail pulling device 20 is placed upon the two rail ends 21 (Fig. 9 and 2) in order to pull the same towards one another with actuation of the two drives 33 until the rail gap 39 has been eliminated. The force f necessary to do so is registered by the force measuring device 34 and recorded. In order to positively preclude an incorrect force measurement which might be caused by the rails becoming wedged, the two rail ends are pulled together repeatedly until the rail portions delimited by the removal of the rail spikes are in a tension-free state. Parallel to that, the actual rail temperature is measured with the aid of the temperature measuring device 35, and the length I of the rail gap is measured by the odometer device 40.
In the meantime, the second and third machines 4,5 have been moved on to the next damaged rail section in order to detach the rail anchors over the required distance.

(0026] On the basis of the measuring values passed on to the control- and computing unit 38, and the lengths - stored in the storage medium 37 - of the replacement rails 14 which are in stock and have already been prepared for optimal welding, the best-suited replacement rail 14 is calculated automatically. The rail cutting saw 17 is displaced forward on the saw guide 16 in the working direction 44, or in the longitudinal direction of the machine, with the displacement path of the saw being measured, until the length computed by the control- and computing unit 38 for the rail section 42 to be removed has been reached. Said length was calculated while taking into account the length of the selected replacement rail 14 as well as the difference between the actual rail temperature and a stored neutral temperature. Also to be taken into account with regard to the required length of the replacement rail 14 is the burning-off occurring due to the double flash-butt welding, as well as the reduction of rail length after the upset impact, in order to finally obtain a desired rail tension despite these length reductions after welding of the replacement rail 14. After a second separating cut (Fig. 10) by means of the rail cutting saw 17 and the removal of the rail spikes, the severed damaged rail section 42 is removed. It is also possible, of course, to cut off a piece of suitable length from a longer replacement rail 14, particularly if a suitable replacement rail 14 is not on hand.

[0027] With the aid of the crane jib 12, the replacement rail 14 selected by the control- and computing unit 38 is set down upon the track 7, with one end being positioned adjoining a rail end 24 (Figs. 11,12). The second end of the replacement rail 14 is arranged overlapping the second rail end 24, if necessary - in dependence upon the difference between the actual and neutral temperatures. To secure the position of the replacement rail 14 placed on the track 7, the corresponding rail spikes are driven into the sleepers (Fig. 13).

[0028] As can be seen in Fig. 14, the first machine 2 - after lowering the raised on-track undercarriage 6 - is moved forward in the working direction 44 until it is possible to work on the rail ends 24 with the rail grinding device 27. Subsequently (Fig. 15), the machine 2 moves on to the next installation site 43, where the described working steps are repeated.

[0029] The two welds for welding the replacement rail 14 are executed by means of a following welding machine, not shown, using the flash-butt welding method, wherein the relevant measuring data are passed on by radio or disc from the controlling and computing unit 38 to a control unit of the welding machine.

Claims

1 A method of removing damaged rail sections (42) from welded rails (25) of a track (7) having an actual rail tension and an actual rail temperature, in which, after two separating cuts - with formation of a rail gap (39) and two rail ends (24) - a replacement rail (24) having two ends is welded to the two rail ends (24), wherein a) after a first separating cut, both rail ends (24) are gripped by means of a rail pulling device (20) connecting said rail ends to one another, and are pulled towards one another with application of a pulling force f for eliminating the rail gap (39), b) in doing so, the pulling force f required for pulling the rail ends (24) together as well as an actual rail temperature are registered for calculation of that length of a replacement rail (14) which is required for producing a desired rail tension after both ends of the replacement rail (14) have been welded to both rail ends (24), c) a second separating cut is executed, with corresponding path measurement, spaced at a distance from the first separating cut as calculated on the basis of the selected length of the replacement rail (14).

2. A method according to claim 1, wherein, after the first separating cut, the rail gap (39) formed by a distance of the two rail ends (24) is measured.

3. A method according to claim 1, wherein replacement rails (14) of various lengths are kept on hand and are stored with reference to their respective length in a storage medium (37) of a control- and computing unit (38).

4 A method according to claim 3, wherein a calculation of the required length of the replacement rail (14) is automatically adapted by the control-and computing unit (38) to fit one of the stored replacement rails (14), so that the latter may be welded in unchanged length to both rail ends (24), thus achieving the desired rail tension.

5. A machine (2) comprising a machine frame (8), mobile on on-track undercarriages (6), for preparation of a rail weld, having the following features:

a) a rail storage facility (13) for storing a number of replacement rails (14), b) a crane jib (12), vertically adjustable and rotatable by drives (11), for gripping and unloading a replacement rail (14), c) a vertically adjustable rail cutting saw (17) which is adjustably mounted on a saw guide (16) extending in a longitudinal direction of the machine, d) a rail pulling device (20) mounted on the machine frame (8) for adjustment by means of drives (19) and having two pairs (31), spaced from one another, of rail clamps (32) designed for gripping and pulling together two rail ends (14), e) a pair (21), arranged in immediate proximity to an on-track undercarriage (6), of lifting rams (22) fastened to the machine frame (8) and designed to be lowered for placement upon a track (7), the lifting rams being provided for lifting an adjacent on-track undercarriage (6) from the track (7).

6. A machine according to claim 5, wherein the rail pulling device (20) is equipped with a force measuring device (34) for registering a force f required for pulling both rail ends (24) together.

7. A machine according to claim 5, wherein a temperature measuring device (35) is provided for registering an actual rail temperature.

8. A machine according to any one of claims 5 to 7, wherein a control- and computing unit (38) is provided in which various lengths of the replacement rails (14) on hand in the rail storage facility (13) are stored.

9. A machine according to claim 5, wherein the rail cutting saw (17) is coupled to an odometer (41) for automatically detecting a displacement path along the saw guide (16).

10. A machine according to claim 8, wherein the control- and computing unit (38) is designed for input of a value of a neutral temperature and, for registering respective measuring values, is connected to an odometer (40), the temperature measuring device (35) and the force measuring device (34).

11. A machine arrangement for preparation of a rail weld with a machine according to claim 5, wherein a second machine (4) is provided which is independently mobile by means of a motive drive (9) and has a device (28) for detaching rail anchors.

12. A machine arrangement according to claim 11, wherein a third independently mobile machine (5) having a device (28) for detaching rail anchors is provided, said third machine (5) being transportable by the second machine (4) with the aid of a transporting device (30) for transfer travel to a track construction site.