METHOD FOR REPAIRING A ROLLED RAIL INSULATION JOINT AND USE OF A MOLDED BODY MADE OF OPEN-PORE COMPOSITE MATERIAL AS A REPAIR INSERT IN THIS METHOD

Description

[0001] The invention relates to a method for repairing a rolled rail insulation joint.

[0002] In rail transport systems, such as railways, the electrically conductive rails are often used as a transmission medium for electrical signals. This is the case, for example, with track circuits used in track vacancy detection systems, where a section of track is detected as occupied because the rails are short-circuited by the electrically conductive wheel sets, thereby changing the electrical properties of the connected track circuits. In order to assign dedicated track circuits to specific track sections along the line, the electrical conductivity of the rails must be interrupted at the track section boundaries. This is achieved by inserting an electrically insulating layer in the form of a solid insert between the interfaces of the rail ends.

[0003] Insulated joints such as those known from US 5,503,331 or DE 31 08 339 C2 are subject to high levels of wear due to the different material properties between the insulation and the rail, the high loads caused by the rail vehicles passing over them, and the weather-related expansion or shrinkage of the rail.

[0004] Furthermore, deformation of the rail head edges can cause bulges, known as over-rolls, to form, which lead to electrical short circuits between the rail sections to be insulated and thus negate the insulating effect. In this case, the track detection system is disrupted, making regular operation on the line impossible. To eliminate this disruption, the over-roll must be removed using a suitable tool, such as an angle grinder with a cutting disc. In many cases, the entire insulated joint or parts of it are replaced at considerable expense.

[0005] If the most cost-effective option is chosen—removing the abutting rail material, including the deformed insulating layer, known as an insulating joint intermediate insert, using tools—a gap remains that has not been filled to date, or has only been filled using temporary, temporary methods such as hot glue. The short circuit is then eliminated; however, metal shavings caused by the wheel-rail system or rail grinding work can collect in the gap immediately or after a short time, potentially leading to another short circuit. This also occurs with previous methods, as the insulating materials used are not weather-resistant, among other things, and methods for introducing material-independent anchoring points into the existing intermediate insert are not yet known.Due to the strong vibrations in the insulation joint caused by the wheel rolling over it, the inserted insulation material falls out to the side, so that the durability of previous methods is only short-lived.

[0006] Furthermore, the lack of an insulating layer at the rail head promotes rolling over and subsidence of the ballast bed, since no counterpressure can be built up against the wheel if the soft insulating layer is completely missing or temporary. This leads to very high localized loads on the edges of the opposing rail ends, which then also negatively impacts the ballast substructure. In cases of significant subsidence, distinct "hammering" noises can be heard.

[0007] Attempts have therefore been made to develop practical repair methods to close the gap resulting after the over-rolling has been removed using suitable insulating materials, thus completely and permanently restoring the insulation layer. Furthermore, the methods should ideally be used preventively as soon as the degree of over-rolling has reached a critical state. This is the case when iron filings already present on the rail could lead to a short circuit in the track circuits. Attempts have been made to inhibit the over-rolling by using newly developed insulating materials with high compressive and abrasion resistance, such as nano-composite materials, to restore the deformed or severed insert. This increases the service life of the insulating joint reconditioned using the method according to the invention.

[0008] A suitable repair method for this purpose, which is still considered to be of high quality, is known from DE 10 2015 016 866 A1. This well-known repair method for rolled insulation joints is characterized by the fact that it can be applied quickly and easily by maintenance personnel without replacing the entire rolled insulation joint or parts of it, thus significantly extending the service life of the insulation joint.

[0009] The present invention is now based on the object of further developing the method described above in such a way that the destroyed insulating layer can be completely and particularly durably restored without having to replace the entire insulating joint or parts thereof.

[0010] This object is achieved according to the invention by a method having the features of claim 1.

[0011] Accordingly, the rolled rail material and the deformed insulating insert located underneath are ground out and / or separated from the rail insulating joint in such a way that a gap is created which corresponds in terms of width and thickness to the insulating insert and which is sufficient to absorb the forces of the insulating material to be introduced, into which gap a repair insert is inserted and then bonded in a material-locking and / or form-fitting manner to the remnants of the original insulating insert remaining in the gap and to the end faces of the rail ends adjoining the gap, wherein a molded body made of open-pore composite material is used as the repair insert, which has an adhesive / binding strength with isocyanate-containing adhesives of more than 10 N / mm2.

[0012] The repair insert has the following advantageous properties in particular: At least 10 mm high and ideally designed in the shape of a rail head contour, pressure and abrasion resistant with an E-modulus of preferably at least 3000 MPa, temperature resistant up to 120°C, current insulating, preferably with a volume resistance of at least 10 11< Ohm per cm, weather and UV resistant, low water absorption of less than 2%, elastic properties with an elongation at break of at least 20, wearing with the rail.

[0013] In this case, the rolled rail material and the deformed insulation layer underneath are preferably ground and / or cut out using suitable tools, for example an angle grinder with a cutting and sawing disc, in such a way that a gap is created that corresponds in terms of width and thickness to the insulation insert and is sufficient to absorb the forces of the insulating material to be introduced, wherein additional recesses are preferably made in the existing insulation layer using suitable tools, such as a cordless screwdriver with a drill bit after grinding, after which the contact surfaces that come into contact with the new insulation material are advantageously mechanically and / or chemically cleaned and the sides of the gap are sealed against the leakage of insulation material or the adhesive used for this purpose,a suitable (from the outset or at least after curing) high-strength insulation material is inserted into the gap and any protruding new insulation material is adapted to the rail contour by grinding using a suitable tool.

[0014] The upper edge of the old sawn-out insulation joint insert is preferably sanded to an uneven depth, ideally chamfered on the sides at an angle of > 45°, with the new insulation material being inserted into the resulting gap.

[0015] For the insulation material or adhesive to be applied, a primer is preferably applied to the contact surfaces in order to improve the surface properties.

[0016] For a particularly fast application of the process, a liquid insulating material is ideally introduced with a syringe, which hardens in a short time.

[0017] When inserting a solid insulation material into the gap, it is advantageous to have anchor recesses on the underside into which liquid adhesive can penetrate during gluing.

[0018] The recesses, which should also be present in liquid insulation material, are preferably made in the old insert in such a way that they are formed at opposite angles.

[0019] The recesses in the old insert are preferably made using a suitable template.

[0020] To seal and prevent the new insulation material or the adhesive required for it from leaking into the gap, a seal is first attached, ideally with adhesive tape on the sides, and remains there as a permanent marking.

[0021] To form the introduced liquid insulation material in the shape of the rail contour, the sealing material is also used as formwork.

[0022] The process can also be used to completely or largely replace the old insulating joint interlayer.

[0023] If the insert is replaced in whole or in part, the seal is applied around the entire intermediate joint.

[0024] Instead of the anchors formed in the recesses using adhesive or new insulating material, holding devices for the new repair insert in the form of brackets, split pins or cramps can also be used for anchoring.

[0025] Advantages of the invention: Insert any advanced, resilient insulation material with a firm anchorage to the existing insulation. Completely restores and improves the damaged insulation layer without having to replace the entire insulation joint or parts of it. Prevents lateral slippage of the inserted insulation material by unevenly sawing or chamfering the upper edges of the remaining part of the old insulation joint at an angle of > 45°. Improves the surface properties of the insulation material to be inserted or of the adhesive by applying a primer to the contact surfaces. This method allows for rapid troubleshooting and the prevention of subsequent problems by applying a liquid insulation material that cures quickly. The advantage of this method is that no precise grinding of the gap is required.Additional protection against sideways and upward slippage of a fixed insert through anchor recesses on the underside of the fixed repair insert, which is inserted into the gap using adhesive and the resulting anchors through depressions in the old insert. A particularly high anchoring effect is achieved when the depressions are made at opposite angles. Quality assurance of the process through the use of a template for creating the angled depressions. This allows the depth, size and location of the depression to be optimally aligned. Simple sealing of the side surfaces, ideally with adhesive tape to prevent the leakage of liquid insulation material or adhesive. At the same time, the sealing tape can be used as a permanent marker for maintenance staff that a repair to the insulation joint has been completed. At the same time, the adhesive tape can be used as a formwork element in the shape of the rail contour.This ensures that the applied insulation material or adhesive adheres to the rail contour and does not require sanding. This process can also be used to replace entire intermediate inserts or large sections of them. This requires sealing around the entire insulating joint. By using retaining devices for the new repair insert in the form of brackets, split pins, or clamps, the process can be used without adhesives. This results in greater durability and resistance of the insulating joints.

[0026] With the method described in the invention, it is now possible to replace the otherwise simple interference suppression by grinding the over-rolling with a long-lasting repair process. Since insulated joints have already been partially replaced completely during over-rolling due to a lack of suitable repair methods, considerable costs can be saved by the method according to the invention. Reduction of maintenance costs:

[0027] The new process and the resulting use of more resilient materials increase the so-called "service life" of insulated joints. This eliminates the need for early replacement of the entire insulated joint and the associated high costs.

[0028] Since the repair prevents metal shavings from accumulating in or on a suppressed insulation joint, fewer faults occur than before, thus reducing maintenance costs.

[0029] By applying the procedure as part of regular inspections by maintenance staff, potential malfunctions can be identified and avoided in a timely manner. Reduction of disruptions and delays:

[0030] Because the application of these methods reduces or eliminates disruptions caused by rolling and metal chips, the availability of the rail infrastructure is increased. The effects include: More punctual trains Energy savings on trains through fewer minutes of delay Reduction in ticket reimbursement costs

[0031] In particular, the advantages achieved by the invention are that the insulated joint is even more resistant and less susceptible to wear against rolling over and short circuits caused by metal chips, the durability is increased and the maintenance costs of the insulated joints can be significantly reduced.

[0032] An embodiment of the invention is explained in more detail with reference to a drawing. In the drawing: Fig. 1 a section of a rail track in perspective view with deformed insulating joint intermediate insert with rail over-rolling on the opposite upper rail edges, Fig. 2 an insulating joint sawn open according to the inventive method for introducing a new insulation layer to repair the defective insulating joint intermediate insert, Fig. 3 a cross-sectional view of an inventive sawn open insulating joint with chamfering on the sides and introduced depressions with opposite angles, Fig. 4 an insulating joint with attached sealing template, Fig. 5 the sealing template according to. Fig. 4 in perspective view, Fig. 6 the sealing template with attached drilling template, Fig. 7 a sawn-open insulating joint prepared for the process with sealed side surfaces for the introduction of the new insulating material, Fig. 8 a repair insert, Fig. 9 a cross-sectional view of an insulating joint with inserted repair insert, Fig. 10 a cross-sectional view of an embodiment anchored with a bracket, Fig. 11 a cross-sectional view of an embodiment anchored with a split pin, and Fig. 12 a cross-sectional view of an embodiment anchored with staples, Fig. 13 a seal which is glued to the rail flank with the installation month shown facing upwards.

[0033] Identical parts are provided with the same reference numerals in all figures.

[0034] Fig. 1 shows a section of a rail track 1 in the area of ​​a so-called insulated joint 2. At such an insulated joint 2, two adjacent rail elements 4 meet, whereby, for reasons of safe train dispatch, reliable electrical insulation of the rail elements 4 from one another must be ensured. In the area of ​​the insulated joint 2, the rail elements 4 are thus positioned at a distance from one another, forming an insulating gap 6. The insulating gap 6 is initially filled with an insulating insert 8, which is intended to ensure reliable insulation even during long operating times.

[0035] However, due to operational reasons, it is inevitable that the rail ends 10 meeting at the insulating joint 6 are deformed locally, particularly at the joint edge, and are thereby reshaped in the direction of the insulating gap 6. This ultimately leads to the Fig. 1 shown state of the so-called "rolled" rail material, in which the rail ends 10 abut each other due to deformation and thus electrically bridge the desired insulation.

[0036] To remedy the resulting problem, the repair according to the invention described below is carried out. First, the insulation gap 6 and the deformed insulation insert 8 located therein are ground out using suitable tools, such as an angle grinder with a cutting / saw disk, so that a free-standing gap 12 is created that corresponds in thickness and width to the insulation insert and absorbs sufficient forces for the insulating material to be introduced, as shown in Fig. 2 The insulating insert 8 is removed only in its upper region, since experience has shown that the problem of over-rolling only affects the upper region; the deeper regions of the insulating insert 8, however, remain intact and continue to provide the desired insulating effect.

[0037] Fig. 3 shows the insulating insert 8 after this treatment step in perspective. The insulating insert 8 is ideally chamfered on the sides at an angle of > 45°, i.e., cut out at an angle, with the newly inserted insulating material later being inserted into the gap 12.

[0038] Subsequently, the gap 12 is prepared for the intended filling with new, temporarily liquid insulation material. The sides of the gap 12 are sealed against the leakage of insulation material or adhesive used therefor. According to one aspect of the invention, the Fig. 4 The sealing template 14 shown in Fig. 5 The sealing template 14, shown in perspective view, is preferably made of non-conductive and non-adhesive material and has an inner surface 16 that mimics the rail head contour. The two opposing sealing jaws 18 are connected by a web 22 provided with a filling slot 20.

[0039] The sealing jaws 18 are provided with magnets 24 for temporary fixation to the rails 2, which, in particular, ensure the desired contact pressure against the rail and thus the sealing force. The magnets 24 also achieve a cleaning effect by absorbing any iron filings that may be present nearby, for example, those generated by abrasion. This reduces the risk of a short circuit caused by the filings.

[0040] According to one aspect of the invention, the sealing template 14 is also provided with a drilling template 28 pivotably attached to the web 22 via a hinge 26, as shown in Fig. 6 According to one aspect of the invention, it is provided that a suitable tool, such as a cordless screwdriver with a drill and the drilling template 28, can be used to drill into the Fig. 3 The remaining parts of the existing insulation insert 8 are to be drilled with anchor holes 30, which are preferably aligned in pairs in opposite directions at an offset angle. This is shown in the embodiment with the folding mechanism in Fig. 6 , in which the drilling template insert 32 can be inserted into the filling slot 20 of the sealing template 14.

[0041] This drilling template insert 32 is preferably made of insulating solid material, ideally of an environmentally friendly, easy-to-clean PLA or ABS that does not bond with the liquid insulation material or adhesive. The underside is shaped like a rail contour and the top side has drill holes 34. The drilling template insert 32 preferably has a locking plug insert 36. In this combination, the drilling template insert 32 is ideally suited for creating the anchor holes 30 in the old insulation insert 8. Subsequently, the contact surfaces potentially coming into contact with the new insulation or sealing material are mechanically and / or chemically cleaned. To improve the surface properties for the insulation material to be applied, a primer is preferably applied in addition to the cleaning.

[0042] After applying the sealing template 14, ideally made of a non-conductive, dirt- and water-repellent material, as well as heat-resistant up to 450 °C, especially silicone type 3, which does not bond with the liquid insulation material or adhesive, and after creating the anchor holes 30 in the old insulation insert 8, the insulation joint 2 is prepared for the actual repair. The resulting cavity in the insulation gap 6 is filled with new insulation material. This can be done either by "pouring" with liquid material, as may be required, for example, in the context of a quick repair. As shown in Fig. 7 As shown, a liquid insulating material can be used, which is poured into the resulting cavity using the sealing template 14 as formwork and hardens there. The insulating material also flows into the anchor holes 30; upon hardening, a fixing body is created that is held in position with a positive fit and is thus protected against unwanted displacement or falling out.

[0043] Preferably, and especially for permanent repairs, a fixed repair insert 38 is used, as shown in Fig. 8 is shown. According to one aspect of the invention, such a repair insert 38 is glued into the resulting gap 12 of the insulating joint 2 after grinding off the over-rolling. On the one hand, it ensures that no more chips can collect in the gap 12. On the other hand, it primarily serves to mechanically stabilize the gap 12 and the insulating joint 2 as a whole, thus preventing (re-)rolling in the future. To meet these requirements, the insert should advantageously be made of an open-pore composite material with the following properties: Preferably pressure and abrasion resistant with an E-modulus of preferably at least 3000 MPa, preferably at least 10 mm high and ideally designed in the shape of a rail head contour, preferably temperature resistant up to at least 120 °C, current insulating with a volume resistance of preferably at least 10 11< ohms per cm, preferably weather and UV resistant, low water absorption of preferably less than 2%, preferably elastic properties with an elongation at break of preferably at least 20%, preferably wearing together with the rail.

[0044] In particular, according to one aspect of the invention, the repair insert 38 is designed such that it can withstand the strong vibrations caused by the rail vehicles passing over it during operation and firmly bonds optimally and independently of the material with any remaining remnants of the original insulating insert 8.

[0045] To enable this, the repair insert 38 is provided on its underside with inverted wedge-shaped protrusions 40. These are adapted to the position and orientation of each associated anchor hole 30 and, in conjunction with the anchor holes 30, are designed to accommodate an initially liquid and later hardening adhesive. After the adhesive has hardened, an anchor body 42 forms in each anchor hole 30 together with the associated protrusion 40. This anchor body 42 engages positively both in the protrusions 40 and in the anchor holes 30, thus securing the repair insert 38 in the gap 12.

[0046] The repair insert 38 is then glued into the gap 12 with liquid adhesive, whereby a certain fixing effect is already achieved by the adhesive on the end faces. The applied adhesive then forms, together with the introduced anchor holes 30 and the respective anchor recess 40 in the solid repair insert 38, a material-independent anchor 42 made of adhesive as a form-fitting composite, as shown in Fig. 9 which prevents the repair insert 38 from slipping in the gap 12.

[0047] After the repair insert 38 has been inserted and fixed as described above, any protruding new insulation material is ground to the profile of the rail 1 using a suitable electric grinding tool, for example an angle grinder with a coarse abrasive fan disk, ideally with 40 grit for high grinding performance.

[0048] In an alternative inventive embodiment, two-part insulating repair inserts 44 as in Fig. 10 bis 12 shown, which are held together with brackets 46, split pins 48, or staples 50. Other anchoring elements such as adhesives, anchor recesses, adhesive tape, etc. can be dispensed with if necessary. In particular, a (new) insulating repair insert 44 can be connected in this way to the (old) insulating insert 8 remaining in the rail joint.

[0049] Fig. 13 shows a seal 51, which, after the repair has been completed, is affixed to the rail flank of the insulated joint, ideally behind the iron plate, with the installation month shown facing upwards. This makes it possible to identify when the insulated joint was repaired. Furthermore, the seal protects the insulated joint from the effects of weather. Additional information such as a QR code on the seal, as shown in Fig. 13To see, additional information such as material properties, batch number, material numbers or other customer-specific information can be provided. List of reference symbols

[0050] 1 Rail run 2 Insulated joint 4 Rail element 6 Insulated gap 8 Insulated insert 10 Rail ends 12 Gap 14 Sealing template 16 Inside 18 Sealing jaws 20 Filling slot 22 Web 24 Magnets 26 Hinge 28 Drilling template 30 Anchor holes 32 Drilling template insert 34 Drill holes 36 Locking insert 38 Repair insert 40 Bulges 42 Anchor body 44 Repair insert 46 Bracket 48 Split pin 50 Staple 51 Seal

Claims

1. A method for repairing a rolled-over rail insulation joint, in which the rolled-over rail material and the deformed insulating insert (8) situated therebeneath are ground out and / or separated out such that a gap (12) results, corresponding with regard to width and thickness to the insulating insert (8), into which gap a repair insert (38) is inserted and subsequently is connected in a materially-bonded and / or form-fitting manner with the remainders of the original insulating insert (8) remaining in the gap (12) and with the end faces of the rail ends (4) abutting against the gap (12), characterized in that as repair insert (38) a moulding of open-porous composite material is used, which has an adhesive / bonding strength with adhesives containing isocyanate of over 10 N / mm2.

2. The method according to Claim 1, in which before the introduction of the repair insert (38) into the gap (12), a number of anchor bores (30) are introduced into the remainders of the insulating insert (8) remaining in the gap (12).

3. The method according to Claim 2, in which the repair insert (38) is provided with indentations (40) associated with the anchor bores (30) such that the respective anchor bore (30) together with the indentation (40) associated with it can be filled with adhesive, which after hardening forms an anchor body (42) connecting the remainders of the insulating insert (8) with repair insert (38) in a form-fitting manner.

4. The method according to one of Claims 1 to 3, in which the gap (12) is produced by grinding down the metallic over-rolled rail ends (4) by means of an angle grinder with cutting disc in the thickness of the insulating insert (8) and subsequently by means of a saw blade for removing the deformed region of the insulating insert.

5. The method according to one of Claims 1 to 4, in which after the repair, a label (51) with a marking representing the month of installation is affixed onto the rail flank.

6. The method according to one of Claims 1 to 5, wherein the repair insert (38) has the following characteristics: - at least 10 mm high and ideally configured in the rail head contour form, - pressure- and abrasion-resistant with a modulus of elasticity of preferably at least 3000 MPa, - temperature-resistant up to 120°C, - current-insulating with a contact resistance of at least 1011 Ohm per cm.

7. The method according to one of Claims 1 to 6, in which the repair insert (38) is connected by means of brackets (46), cotters (48) or cramps (50) to the remainders of the original insulating insert (8) remaining in the gap (12).