EP2894719B1 - Device for diverting a short-circuit current - Google Patents

Description

The invention relates to a device which is suitable for guiding electrical lines or as a holding device for persons and a rail vehicle having such a device.

For protection against mechanical damage, electrical cables, such as cables or cables, are often used in rail vehicles in or on profiled bodies, such as, for example, railway vehicles. Metal pipes, especially laid in aluminum pipes.

If the electrical line is still damaged, in particular insulation, a current can be transmitted to the pipe or rail and an undesirable short circuit occur, which is very problematic especially in high-voltage lines. For safety, the pipes or rails in which or on which the lines are routed are grounded.

A grounding is also known in the field of hose technology. DE3543233 discloses a contact part for hoses with metal insert, consisting of a base ring with a discharge device made of electrically conductive material, which can be electrically connected by a dimensioned in the diameter of the metal insert of the hose cutting lip with the metal insert of the hose. The grounding can be done via a grounding clamp, which is connected to the base ring via an externally applied drainage lug. With this structure, an electrostatic discharge is possible, but no short circuit safety.

DE 10 2005 003 654 A1 relates to a power cable support structure for a vehicle, comprising power cables having at least two different outer diameters and comprising at least two cables for each outer diameter, a metal protective tube into which the power cables are inserted, wherein in the protective tube, the power cables with a small outer diameter in the interstices are arranged between the outer surface of the power cable with a large outer diameter and the inner surface of the protective tube. The thermowell is grounded through a braided shield covering motor power cables.

US 2,913,699 concerns the earthing of a pipeline in airplanes by means of a flexible grounding line fitted on the outside with a clip on the pipeline.

• Die Kurzschlussstromtragfähigkeit der Verbindung muss dem maximal möglichen Kurzschlussstrom entsprechen.
• Die Erdungsverbindung muss überprüfbar sein.

Grounding is a particular challenge in the case of aluminum tubes, as several factors make proper grounding difficult. The essential requirements for earthing connections on rail vehicles are the following:

• The short-circuit current carrying capacity of the connection must correspond to the maximum possible short-circuit current.
• The grounding connection must be verifiable.

The attachment of earthing cables to pipes or rails can be done by welding. However, electrical connections in particular to aluminum pipes are not so easy to implement. Welded parts for aluminum pipes are expensive and unwieldy.

Furthermore, an electrical and mechanical connection of grounding lines to hollow profiled bodies with a thin wall by means of welding is unfavorable, since a thermal deformation can occur due to the registered energy. In the interior of the profile body damaged areas may arise and laid in the interior of the profile body electrical lines can be chafed at these damaged areas during operation.

The object of the invention is to provide a solution to these problems.

The object is achieved by a rail vehicle according to claim 1. Advantageous embodiments of the invention are specified in subclaims.

• einen elektrisch leitfähigen Profilkörper, insbesondere aufweisend oder bestehend aus Metall,
• eine elektrische Leitung, die in oder an dem Profilkörper angeordnet ist,
• zumindest eine den Profilkörper außen umgreifende elektrisch leitfähige Erdungsschelle, wobei ein Strom von der Außenseite des Profilkörpers auf die Erdungsschelle übertragbar ist,
• zumindest ein Befestigungsmittel womit der Profilkörper an einem tragfähigen Gegenstand oder Untergrund befestigt ist,
  wobei
• eine flexible Erdungsleitung mit der Erdungsschelle gekoppelt ist, und die Erdungsschelle über die flexible Erdungsleitung mit einem leitfähigen Teil des Schienenfahrzeugs verbunden ist,
• das Befestigungsmittel elektrisch leitfähig ist und das Befestigungsmittel einen höheren Widerstand aufweist als die Erdungsschelle.

Specified by the invention thus a rail vehicle, comprising a device comprising

• an electrically conductive profile body, in particular comprising or consisting of metal,
• an electrical line arranged in or on the profile body,
• at least one electrically conductive earthing clamp which encompasses the outside of the profile body, wherein a current can be transmitted from the outside of the profile body to the grounding clamp,
• at least one fastening means with which the profile body is fastened to a load-bearing object or ground,
  in which
• a flexible grounding line is coupled to the grounding clip, and the grounding clip is connected to a conductive portion of the railroading vehicle via the flexible grounding line;
• the fastener is electrically conductive and the fastener has a higher resistance than the grounding clamp.

The device is used in the rail vehicle for guiding electrical lines, in particular cables. In this context, the profile body may be referred to as a guide body, mounting body or holding body. The device for guiding electrical lines in or on the substructure of the rail vehicle can be used particularly advantageously. A particularly preferred application is the cable routing of the train busbar. The profile body can be attached to a substructure, in particular on a subframe, of the rail vehicle (especially a car body) or fastened there. The attachment there can be done with the mentioned fastener.

The device is also usable in the rail vehicle as a holding device for persons, wherein the profile body is used for holding or by persons. The holding device thus has a mentioned earthing clamp, which serves to dissipate a current and a fastening means with which the holding device can be attached to an object or substrate. Specific examples are railings, handrails, for example, at railway facilities, which are covered with overhead lines, and handrails in rail vehicles and other vehicles, especially public transport.

By using a grounding clamp the disadvantages of a welded grounding described above are avoided. Under a clamp an object is understood, which engages around the electrically conductive profile body. Preferably, the clamp has a clamping device, by means of which the clamp the surface of the profile body can be pressed, so that a non-positive connection and preferably also positive connection can be produced.

According to another basic idea of the invention, said earthing clamp and the fastening means for fastening the profile body to a load-bearing object or ground are separate parts. The fastener is therefore not needed to ground the profile body. The grounding does not have to be ensured via the fastening means. Thus, no electrical connection must be ensured via the fastening means. Changes in the attachment, such as in the overhaul or maintenance of a rail vehicle, thus can not unintentionally lead to the loss of grounding contact. For example, the fastening means can be screwed to a substrate, wherein care must not be taken that a sufficient electrical line for the purpose of grounding is ensured by the screw. Conversely, according to the invention, the earthing clamp does not serve to fasten the elongated profile body.

The mentioned profile body is an elongated body.

Preferably, the profile body as a conductive material on metal, preferably predominantly metal, or consists of metal. In particular, the profile body is made of steel or aluminum. A profile body of a first metal may be coated on at least the outside with another conductive metal. An example of this is a galvanized steel.

The shape of the profile body, such as e.g. straight or curved, is not limited.

Preferably, the profile body is rigid.

The cross-sectional shape of the profile body, such as e.g. angular, round, angled, is not limited.

The profile body may be solid or hollow inside. A hollow profile is preferably such that a flow can flow from the inside to the outside. In other words, preferably, the inside and the outside, in other words the surfaces on the inside and on the outside, are electrically conductive.

Examples of a solid profile body are a rod, a rod, a T-profile or a rail. These profiles can be used advantageously for the attachment of electrical cables. For example, electrical lines can be arranged within a rail. An example of this is a C-shaped rail. Another example is a roundish rail, for example in cross-section in the form of a circle segment. Furthermore, rods or rails are also suitable as a holding device for persons, for example as railings.

In another variant of the invention, the profile body is a hollow profile body, in particular a tube or an angular hollow profile. Particularly preferred is a steel or aluminum tube. In a hollow profile body, one or more electrical lines, in particular cables, can be guided. The electrical lines are, as with other forms of the profile body, preferably provided with an insulation.

The mentioned earthing clamp is preferably made of metal, in particular of stainless steel. As mentioned, a current is transferable from the profile body to the grounding clamp, i. transferable from the outside of the profile body on the clamp. The earthing clamp is in electrical contact with the outside of the profile body. The outside of the profile body is conductive for electrical power.

The device includes a flexible grounding line coupled to the grounding clamp, which may mean a direct or indirect conductive connection to the grounding clamp, such that a current may drain from the grounding clamp via the grounding line. For example, the grounding line can be clamped, screwed, soldered or welded to the clamp. For example, the grounding clamp and the grounding lead may be connected via a cable lug which is clamped to the grounding clamp.

A preferred material for the grounding line is copper.

The cross sections of the grounding line and the grounding clamp are adjusted to the desired current conductivity for deriving a short-circuit current. The cross-sectional area of the grounding clamp is preferably at least 50 mm ² , more preferably at least 60 mm ² , even more preferably at least 100 mm ² . The Meaning and definition of the cross-sectional area is explained with reference to the embodiments.

The cross section of the grounding line, in particular a grounding line made of copper, is preferably at least 10 mm ² , more preferably at least 16 mm ² , even more preferably at least 25 mm ² or at least 35 mm ² and most preferably at least 50 mm ² .

Advantageously, the ratio of the cross-sectional area of the grounding line to the cross-sectional area of the grounding clip corresponds to the ratio of the conductivity of the material of the grounding line to the conductivity of the material of the grounding clip. The above-mentioned cross sections of the earthing line can be varied with these ratios. Likewise, the aforementioned cross sections of the earthing clamps can be varied with the mentioned ratios. Maximum short-circuit temperatures and short-circuit currents achievable with the selected cross-sectional areas are mentioned in the example section.

In one embodiment of the invention, at least one layer of a corrosion-protecting, conductive material is arranged between the grounding clamp and the profile body. In particular, this material protects the profile body from corrosion when the profile body is made of, for example, a less noble metal than the grounding clamp. In one variant, the layer is made of a conductive grease, also referred to as contact grease. An advantage of such a fat is that it does not have to be renewed for at least 30 years. Advantageously, the surface of the profile body is cleaned before application of the fat, for example with an organic solvent, in particular alcohol. In another variant, the layer is made of a metal that is nobler than the metal from which the profile body or at least the surface of the profile body is made. In a special variant, the layer is made of tin, copper, zinc, or a combination thereof. A specific example is a copper layer that has a tin coating. For example, the profile body may be coated with such a metal layer, in particular a tin, copper or zinc layer, at least where the grounding clamp is attached to the profile body. The variants described can be combined: One or more metal layers can be combined with a layer of grease.

In one embodiment of the invention, the fastening means is a mounting clamp, for example a pipe clamp, when the profile body is a pipe.

The fastening means, in particular a fastening clamp, is electrically conductive. It is possible in this case that a short-circuit current is also dissipated via the fastening means. However, this derivation of the short-circuit current via fastening means is redundant, since the earthing clamp is already sufficiently dimensioned for the purpose of dissipating the current. Furthermore, the fastening means has a higher resistance than the earthing clamp, in order to guide the flow of current substantially via the earthing clamp.

Between a conductive fastening means and the profile body, an insulating means may be provided. However, this is not essential.

The rail vehicle according to the invention is in particular a tram, a locomotive, a railcar, a wagon or a train combination, comprising the device described above. In a special embodiment, the device is arranged on the substructure of the rail vehicle, in particular on a subframe. In particular, the device is attached to the substructure of the rail vehicle, in particular to a subframe. Advantageously, the earthing clamp and a conductive part of the rail vehicle, in particular a conductive part of a substructure, undercarriage or a car body are connected to each other via the already described flexible grounding line, for example a wire mesh or wire rope. In or on the profile body of the device, at least one electrical line of the rail vehicle is preferably arranged, in particular a train busbar.

If the device according to the invention is used as a holding device for persons, then it is preferably arranged in the interior of a rail vehicle, for example in the form of a holding rod.

In a further aspect, the invention discloses the use of the device described above for deriving a short-circuit current. In this case, a short-circuit current is derived from the profile body via the earthing clamp and the flexible grounding line. The device can be used as a grounded device for guiding Lines or used as a grounded holding device for persons, as previously discussed.

Fig. 1

eine Vorrichtung für ein erfindungsgemäßes Schienenfahrzeug in seitlicher Ansicht,

Fig. 2

eine Vorrichtung für ein erfindungsgemäßes Schienenfahrzeug im Querschnitt und

Fig. 3

die Befestigung einer Vorrichtung für ein erfindungsgemäßes Schienenfahrzeug am Unterbau eines Schienenfahrzeugwagens.

The invention will be described below with reference to exemplary embodiments. Show it:

Fig. 1

a device for a rail vehicle according to the invention in a side view,

Fig. 2

a device for a rail vehicle according to the invention in cross section and

Fig. 3

the attachment of a device for a rail vehicle according to the invention at the base of a rail vehicle car.

Fig. 1 shows a device for a rail vehicle according to the invention with an electrically conductive profile body 2, in this case a tube (see Fig. 2 ). On the tube 2, two grounding clamps 3 are attached. The earthing clamps 3 are each clamped with clamping screws 4 to the tube 2, wherein by means of the clamping screws 4 and a respective cable lug 5 is attached to the clamp. At the cable shoes 5 each a grounding line is attached, which in Fig. 2 is shown in more detail. Between the earthing clamps 3 and the tube 2, a respective layer 6 of a conductive material protecting against corrosion is arranged. The layer 6 may be, for example, a layer of conductive grease or a layer of a nobler metal, in particular tin or zinc, with which the tube 2 is coated. It suffices a coating in the area where the clamps 3 are clamped.

Also in Fig. 1 Shown is a fastener 8 in the form of a mounting clamp with a part encompassing the tube 2 and two laterally protruding tabs 10, each having a bore 11. By means of the tabs 10, the device 1 can be attached, for example, to the substructure of a rail vehicle, as in Fig. 3 shown.

In the Fig. 1 illustrated earthing clamps 3 and the fastener 8 are only exemplary. There may be more than the fastener 8 shown and more be present as the grounding clamps 3 shown. Further, the tube 2 may be made longer than in Fig. 1 shown. The device may further comprise a plurality of profile body 2, which adjoin one another.

The width of the earthing clamps 3 is indicated by the arrow B. Depending on the short-circuit current to be dissipated, the width B of the earthing clamp can be chosen differently. The cross section of the earthing clamp 3 results from the width B times the in Fig. 2 shown thickness D of the grounding clamp. 3

Fig. 2 shows a cross section through the device 1, more precisely a cross section through the grounding point 3 and the tube 2. It can be seen how the clamp 3 is clamped by means of the fastening screw 4 and the nut 12 to the tube 2. Furthermore, stiffening webs 7 are shown. At the fixed with the screw 4 on the clamp 3 lug 5 is a grounding line 13, preferably made of copper braid attached. Between the tube 2 and the clamp 3, the layer 6 is arranged from a corrosion-protective, conductive material.

In the interior of the tube 2, an electrical line 15 is laid, comprising an insulation 16 and a conductive core 17. For example, the line 15 is a line of a Zugsammelschiene. In the example only one line is shown and others can be present. If the insulation 16 is damaged, short-circuiting, that is to say the current flow from the conductive core 17 to the pipe 2, can occur. The short-circuit current is conducted via the surface of the tube 2 and the conductive intermediate layer 6 on the earthing clamp 3 and flows through the cable lug 5 and the grounding line 13 from.

Fig. 3 shows a view from below of the undercarriage of a rail car. Fig. 3 shows the attachment of the device 1 to the substructure of a rail vehicle in a sectional view. The previously explained tube 2 is fastened by means of two earthing clamps 8 to cross members 20 of a lower frame. The attachment is done here by screwing. The grounding clamp 3, already based Fig. 1 has been explained, does not serve the attachment, so it is not connected to any part of the substructure or subframe and only clamped to the tube 2. About the already explained cable lug 5, the grounding line 13 is guided to the longitudinal member 21 of the undercarriage and secured thereto. In this case, a schematically illustrated grounding tab 22 is fastened, for example welded, to the longitudinal member 21.

At the grounding tab 22, in turn, the grounding line 13 is attached, for example by means of a screw or welding.

In Fig. 3 only a section of a base frame is shown. Depending rail vehicle carriages, a plurality of pipe sections 2 may be arranged on the underframe, which are preferably arranged in each case in alignment with one another axially, so that a device 1 according to the invention may be composed of several pipe sections 2. Per pipe section preferably two grounding clamps 3 are used, with very short pipes depending on the technical requirement, if necessary, a grounding clamp is sufficient. If the fastening clamps 8 are conductive, ie they could also lead to a short circuit on the pipe 2 to the underframe, they have a higher electrical resistance than the earthing clamps, since the short-circuit current is to be derived predominantly via the earthing clamps 3. Insulation may be provided between the cross member 20 and the mounting clips 8 to prevent current flow, but this is not necessary. In particular, insulation is not necessary if the fastening clamps 8 have a higher electrical resistance than the grounding clamp 3.

As already mentioned, a Zugsammelschiene can be arranged in the interior of the tube 2. Alternatively, any other electrical line may be disposed in the tube 2, for example an electrical line for a brake.

In the following, exemplary cross sections for a ground clamp and exemplary cross sections for a ground line 13 are shown in Table 1. The cross section is calculated from the in Fig. 1 shown width B, a clamp 3 multiplied by the in Fig. 2 shown thickness D. In the illustrated examples of a cross section, the maximum short circuit currents and maximum short circuit temperatures shown in Table 1 are possible. The cross section of the ground wire 13 can be chosen differently. For a 60 mm ² clamp cross section, the optimum cross section of the copper cable is 16 mm ^2, and for a 100 mm ² clamp cross section, the maximum cross section of the copper cable is 50 mm ² . Table 1 Cross section grounding clamp Cross section grounding cable Short-circuit current carrying capacity (I ² t) Maximum short-circuit temperature 60 mm ² 16 mm ² 5.8 MA ² s 337 ° C 100 mm ² 33 mm ² 24.9 MA ² s 500 ° C

Claims (14)

1. A rail vehicle, comprising a device (1), comprising

   - an electrically conductive profile body (2), in particular comprising or consisting of metal,

   - an electrical line (15), which is arranged in or on the profile body (2),

   - at least one electrically conductive grounding clamp (3) surrounding the profile body (2) externally, wherein a current can be transferred from the outside of the profile body (2) to the grounding clamp (3),

   - at least one fastening means (8), whereby the profile body (2) is fastened to a portable object or substrate,
   characterised in that

   - a flexible grounding line (13) is coupled to the grounding clamp (3), and the grounding clamp (3) is connected via the flexible grounding line (13) to a conductive part (21) of the rail vehicle,

   - the fastening means (8) is electrically conductive and the fastening means (8) has a higher resistance than the grounding clamp (3).
2. The rail vehicle according to claim 1, wherein the profile body (2) is made of aluminium or steel.
3. The rail vehicle according to any one of the preceding claims, wherein at least one layer (6) made of a conductive material protecting against corrosion is arranged between the grounding clamp (3) and the profile body (2).
4. The rail vehicle according to claim 3, wherein the layer (6) is made of conductive grease.
5. The rail vehicle according to claim 3 or 4, wherein the layer (6) is made of tin, copper, zinc, or of a combination thereof.
6. The rail vehicle according to any one of the preceding claims, wherein the fastening means (8) is a fastening clamp.
7. The rail vehicle according to any one of the preceding claims, wherein the profile body (2) is a bar or a rail.
8. The rail vehicle according to any one of the preceding claims, wherein the profile body (2) is a hollow profile body, in particular a pipe.
9. The rail vehicle according to claim 8, wherein the electrical line is a rail busbar which is arranged within the hollow profile body (2).
10. The rail vehicle according to any one of the preceding claims, wherein the grounding line (13) is a copper line.
11. The rail vehicle according to any one of the preceding claims, wherein the grounding clamp (3) is made of stainless steel.
12. The rail vehicle according to any one of the preceding claims, wherein the grounding clamp (3) is connected to a conductive part (21) of a substructure, a subframe or a railcar body of the rail vehicle.
13. The rail vehicle according to any one of the preceding claims, wherein the profile body (2) is fastened by the fastening means (8) to a substructure or s subframe of the rail vehicle.
14. The rail vehicle according to any one of claims 1-8, 10 or 11, wherein the device is arranged in the interior of the rail vehicle and is a holding device for people.

Images