A novel multi-point grounding cable, method and system

Abstract

The present invention discloses a novel multi-point grounded cable, method and system, which includes a cable and a grounding wire. The core wire shielding layer, aluminum sheath and steel strip at one end and / or both ends of the cable are grounded through the grounding wire. One or at least two insulating joints are arranged on the cable. The insulating joints disconnect the aluminum sheath and the steel strip inside the cable, so that the aluminum sheaths on both sides of the insulating joint are not connected to each other and the steel strips on both sides of the insulating joint are not connected to each other. Each section of the aluminum sheath and the steel armor disconnected by the insulating joint is grounded at one end through the grounding wire. By arranging multiple insulating joints on the basis of the existing grounding of the signal cable, the aluminum sheath and the steel strip on the signal cable are divided into multiple sections by the multiple insulating joints, and each section of the disconnected aluminum sheath and steel strip is grounded at one end, combining the advantages of single-end and double-end grounding. When subjected to electromagnetic interference, the current induced in each interval section can quickly enter the ground nearby, thereby reducing electromagnetic interference.

Description

Technical Field:

[0001] The present invention relates to the field of railway signal cable construction, and particularly to a new type of multi-point grounding cable. Background Art:

[0002] Railway signal cables are information transmission channels for train operation command systems. To ensure the safety of information transmission in a complex electromagnetic environment, the shielding layer of cable cores, aluminum sheaths, and steel armors usually need to be grounded. The grounding methods are single-end grounding or double-end grounding. Single-end grounding can ensure good grounding of the cable, but the safety is poor. Affected by the certain impedance of the shielding layer of cable cores, aluminum sheaths, and steel armors themselves, the grounding shielding effect of the cable far from the grounding point becomes worse and worse as the distance increases. When the signal transmission channel is interfered by the electromagnetic field, it will affect the electrical characteristics of the cable, which is the current main grounding method. Although double-end grounding can make up for the deficiencies of single-end grounding, there are also problems that cannot be ignored. The closed loop formed by the aluminum sheath and steel armor and the integrated ground wire will enhance the influence of the magnetic field on the cable, and interference currents will be generated on the aluminum sheath and steel tape under the interference of the external magnetic field. In addition, when there is a train traction return current in the integrated ground wire, the current will flow through the metal protective layers such as the cable aluminum sheath and steel armor while flowing through the integrated ground wire. This will cause the shielding effect of the metal protective layer to fail, shorten the distance between the signal cable core and the interference current, and is not conducive to the transmission safety of information.

[0003] The interference current on the cable mainly comes from three aspects. On the one hand, at present, railway cables in China are all laid in cable ducts along the railway line. The signal cable is laid on one side of the cable duct close to the railway line, and the power cable is laid in parallel with the signal cable on the other side of the cable duct far from the railway line. The distance between the signal cable and the power cable is less than 300 mm, and it is easy to be affected by the strong magnetic field of the power cable, interfering with the information transmission of the signal cable. If the electromagnetic field generated by the power cable is relatively large, if the interference current induced on the aluminum sheath and steel armor of the signal cable cannot be quickly diverted, it is very likely to break through the outer insulation layer of the signal cable, resulting in abnormal grounding discharge of the signal cable to the ground and causing operation failures. On the other hand, when the cable is laid, if the outer insulation layer is damaged far from the grounding end, when the cable induces a large current or is struck by lightning, the induced current will discharge abnormally to the ground near the insulation breakage, causing the cable grounding to fail and resulting in cable operation failures. The third aspect is that when using double-end grounding or when the outer insulation layer of a single-end grounding cable is damaged, affected by the train traction return current, the current on the aluminum sheath and steel armor of the cable will discharge abnormally to the ground near the insulation breakage, causing the cable grounding to fail and resulting in cable operation failures. Generally speaking, there are many deficiencies in the current grounding of railway signal cables. Once affected by certain adverse factors, it will directly threaten the safety of the cable.

[0004] From the above analysis of various situations, whether it is single - end grounding or double - end grounding, the damage caused by induced current to the cable cannot be eliminated. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is that the existing single - end grounding and double - end grounding of signal cables cannot eliminate the problem of damage caused by induced current to the cable.

[0006] To solve the above - mentioned technical problem, a technical solution provided by the present invention is: a new type of multi - point grounding cable, including a cable and a grounding wire. The core wire shielding layer, aluminum sheath and steel tape at one end and / or both ends of the cable are grounded through the grounding wire. The feature is that: one or at least two insulating joints are arranged on the cable. The insulating joints disconnect the aluminum sheath and the steel tape inside the cable, so that the aluminum sheaths on both sides of the insulating joint are not connected to each other and the steel tapes on both sides of the insulating joint are not connected to each other. Each section of the aluminum sheath and the steel armor disconnected by the insulating joint is grounded at one end through the grounding wire.

[0007] Further, the insulating joint is a termination box or an insulating layer.

[0008] Further, the grounding wire is connected to the aluminum sheath through a copper - aluminum composite plate, and the grounding wire is connected to the steel tape through a copper plate.

[0009] Further, the aluminum end of the copper - aluminum composite plate is welded to the aluminum sheath, the copper end of the copper - aluminum composite plate is welded to the grounding wire, one end of the copper plate is welded to the steel tape, and the other end of the copper plate is welded to the grounding wire.

[0010] To solve the above - mentioned technical problem, another technical solution provided by the present invention is: a method for reducing the influence of induced current on a signal cable. The method is: at least two insulating joints are arranged on the signal cable. The at least two insulating joints divide the aluminum sheath and the steel tape inside the signal cable into multiple independent and non - connected spaced segments. The aluminum sheath and the steel tape in each spaced segment are grounded through a grounding wire.

[0011] Further, the grounding method of the aluminum sheath and the steel tape in each spaced segment is single - end grounding or double - end grounding.

[0012] Further, at least two of the insulating joints are evenly arranged on the signal cable.

[0013] To solve the above - mentioned technical problem, another technical solution provided by the present invention is: a multi - point grounding system for signal cables, including a signal device, a control device and a signal cable. The signal cable is a new type of multi - point grounding cable as described above. The feature is that: the control device is connected to the signal device through the signal cable.

[0014] The beneficial effects of the present invention are:

[0015] By providing multiple insulating joints on the basis of the existing grounding of the signal cable, the multiple insulating joints divide the aluminum sheath and steel tape on the signal cable into multiple segments, and each segment of the aluminum sheath is not interconnected and each segment of the steel tape is not interconnected. Then, single-end grounding is carried out for each disconnected aluminum sheath and steel tape. The setting of the multiple insulating joints divides the aluminum sheath and steel tape of the cable into multiple segments, and the effect of multi-point grounding is equivalent to carrying out equipotential connection of the aluminum sheath and steel armor of the entire cable through the integrated ground wire, combining the advantages of single-end and double-end grounding. When subjected to electromagnetic interference, the current induced in each interval segment can quickly enter the ground nearby, thereby reducing electromagnetic interference.

[0016] In order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. Brief Description of the Drawings:

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only two of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a structural schematic diagram of the present application.

[0019] Figure 2 It is a structural schematic diagram at the insulating joint.

[0020] Figure 3 It is a structural schematic diagram of the copper-aluminum composite plate.

[0021] Figure 4 It is a structural schematic diagram of the copper-steel composite plate.

[0022] Figure 5 It is a structural schematic diagram of single-end grounding of the cable in the prior art.

[0023] Figure 6 It is a structural schematic diagram of double-end grounding of the cable in the prior art.

[0024] Figure 7 It is a multi-end grounding system for a signal cable.

[0025] In the figure, 1 - cable, 2 - grounding wire, 3 - insulating joint, 4 - copper-aluminum composite plate, 5 - copper-steel composite plate; A - signal device, B - control device

[0026] 1a - core wire shielding layer, 1b - aluminum sheath, 1c - steel tape, 1d - outer insulating layer;

[0027] 4a - Aluminum end of the copper - aluminum composite plate, 4b - Copper end of the copper - aluminum composite plate;

[0028] One end of the copper plate 4a, the other end of the copper plate 5b. Detailed implementation mode:

[0029] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for illustrative purposes and are not used to limit the protection scope of the present invention.

[0030] It should be understood that the various steps recorded in the method implementation mode of the present invention can be executed in different orders and / or executed in parallel. In addition, the method implementation mode may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this regard.

[0031] The names of the messages or information exchanged between multiple devices in the implementation mode of the present invention are only for illustrative purposes and are not used to limit the scope of these messages or information.

[0032] Embodiment 1

[0033] As Figures 1-6 shown, a new type of multi - point grounding cable 1 includes a cable 1 and a grounding wire 2. The core wire shielding layer, aluminum sheath 1b, and steel strip 1c at one end and / or both ends of the cable 1 are grounded through the grounding wire 2. One or at least two insulating joints 3 are provided on the cable 1. The insulating joints 3 disconnect the aluminum sheath 1b and the steel strip 1c inside the cable 1, so that the aluminum sheaths 1b on both sides of the insulating joint 3 are not connected to each other and the steel strips 1c on both sides of the insulating joint 3 are not connected to each other. Each section of the aluminum sheath 1b and the steel armor disconnected by the insulating joint 3 is grounded at one end through the grounding wire 2.

[0034] In this embodiment, the insulating joint 3 is a termination box or an insulating layer; a termination box can be used to form a termination point on the cable 1 that only disconnects and grounds the aluminum sheath 1b and the steel strip 1c, thereby forming the insulating joint 3; or an insulating layer can be made inside the cable 1 during the production of the cable 1 to disconnect the aluminum sheath 1b and the steel strip 1c and reserve the port of the grounding wire 2, thereby forming the insulating joint 3.

[0035] During use, the grounding wire 2 connects and grounds each section of the aluminum sheath 1b and the steel strip 1c, and it can be used in the existing usage mode of the signal cable 1 (one end of the signal cable 1 is connected to the control device B, and the other end of the signal cable 1 is connected to the signal device A).

[0036] Embodiment 2

[0037] As Figures 2-4 shown, this embodiment is obtained by describing in detail the connection relationships of technical features such as the grounding wire 2, the aluminum sheath 1b, and the steel strip 1c on the basis of the first embodiment. The remaining technical features are the same as those of the first embodiment, and the same parts will not be described herein again. The difference between this embodiment and the first embodiment is that the grounding wire 2 is connected to the aluminum sheath 1b through a copper-aluminum composite plate 4 (the copper-aluminum composite plate 4 is an alloy plate with aluminum and copper), and the grounding wire 2 is connected to the steel strip 1c through a copper plate 5.

[0038] In this embodiment, the aluminum end 4a of the copper-aluminum composite plate 4 is welded to the aluminum sheath 1b, the copper end 4b of the copper-aluminum composite plate 4 is welded to the grounding wire 2, one end 5a of the copper plate 5 is welded to the steel strip 1c, and the other end 5b of the copper plate 5 is welded to the grounding wire 2.

[0039] The aluminum end 4a of the copper-aluminum composite plate 4 and the aluminum sheath 1b are both made of aluminum material, and are connected by a cold welding process. The contact point is firm and reliable, not easy to fall off, avoiding poor contact and electrochemical reactions between different materials. Even when passing a large current, it can ensure the safe operation of the cable 1.

[0040] One end 5a of the copper plate 5 and the steel strip 1c are connected by a cold welding process. The contact point is firm and reliable, not easy to fall off, avoiding poor contact. Even when passing a large current, it can ensure the safe operation of the cable 1.

[0041] The copper end 4b of the copper-aluminum composite plate 4 and the copper plate 5 are made of copper material, and are welded together with the copper wire (grounding wire 2). The connection is firm, avoiding false soldering, virtual soldering and electrochemical reactions between different materials. The conductivity is excellent, and no heat will be generated due to poor contact when passing a large current, effectively ensuring the safety of the cable 1.

[0042] To solve the above technical problems, the present invention provides a method for reducing the influence of induced current on the signal cable 1. At least two insulating joints 3 are provided on the signal cable 11. The at least two insulating joints 3 divide the aluminum sheath 1b and the steel strip 1c in the signal cable 1 into multiple independent and non-connected segmented intervals, and the aluminum sheath 1b and the steel strip 1c in each segmented interval are grounded through the grounding wire 2.

[0043] Since the multiple spaced segments are not connected to each other, the single-ended grounding is performed on each disconnected aluminum sheath 1b and steel armor, which solves the problem of double-ended grounding caused by directly setting multiple ground wires 2 for grounding the signal cable 1. As a result, the steel strip 1c and the aluminum sheath 1b of the cable 1 are in parallel with the ground wire 2, and interference current will pass through the steel strip 1c and the aluminum sheath 1b, thus interfering with the core wire of the cable 1. Therefore, in this application, the aluminum sheath 1b and the steel armor of the cable 1 are segmented and disconnected, so as to solve the defects existing in the direct grounding of the above-mentioned cable 1. If each theoretical interval is small enough, the effect of multi-point grounding is equivalent to performing equipotential connection on the aluminum sheath 1b and the steel armor of the entire cable 1 through a comprehensive ground wire, combining the advantages of single-ended and double-ended grounding. When being subjected to electromagnetic interference, the current induced in each interval segment can quickly enter the ground nearby. The grounding and the shielding effect on the core wire are far better than the current grounding method of the cable 1, and the influence of the induced current on the cable 1 can be reduced to the greatest extent.

[0044] Among them, the grounding method of the aluminum sheath 1b and the steel strip 1c in each interval segment is single-ended grounding or double-ended grounding, and they can be continuously connected according to actual needs, which is convenient to operate.

[0045] Among them, at least two insulating joints 3 are evenly arranged on the signal cable 1. The even arrangement ensures the uniformity of each interval segment, thereby ensuring the current discharge effect and preventing the mutual influence of the interval segments due to too large a difference in the length of the interval segments.

[0046] The descriptions of the above embodiments tend to emphasize the differences between the embodiments. Their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated in this article.

[0047] Note that the above is only the preferred embodiment of the present invention and the applied technical principle. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A new type of multi-point grounding cable, comprising a cable and a grounding wire. The core wire shielding layer, aluminum sheath, and steel tape at one or both ends of the cable are grounded through the grounding wire. Characterized in that: One or at least two insulating joints are provided on the cable. The insulating joints disconnect the aluminum sheath and the steel tape inside the cable, so that the aluminum sheaths on both sides of the insulating joint are not interconnected and the steel tapes on both sides of the insulating joint are not interconnected. Each section of the aluminum sheath and the steel tape disconnected by the insulating joint is grounded at one end through the grounding wire.

2. A new type of multi-point grounding cable according to claim 1, Characterized in that: The insulating joint is a termination box or an insulating layer.

3. A new type of multi-point grounding cable according to claim 2, Characterized in that: The grounding wire is connected to the aluminum sheath through a copper-aluminum composite plate, and the grounding wire is connected to the steel tape through a copper plate.

4. A new type of multi-point grounding cable according to claim 3, Characterized in that: The aluminum end of the copper-aluminum composite plate is welded to the aluminum sheath, the copper end of the copper-aluminum composite plate is welded to the grounding wire, one end of the copper plate is welded to the steel tape, and the other end of the copper plate is welded to the grounding wire.

5. A method for reducing the influence of induced current on a signal cable, the method being: providing at least two insulating joints on the signal cable. The at least two insulating joints divide the aluminum sheath and the steel tape inside the signal cable into multiple independent and non-interconnected spaced segments. The aluminum sheath and the steel tape in each spaced segment are grounded through a grounding wire.

6. A method for reducing the influence of induced current on a signal cable according to claim 5, Characterized in that: The grounding method of the aluminum sheath and the steel tape in each of the spaced segments is single-end grounding or double-end grounding.

7. A method for reducing the influence of induced current on a signal cable according to claim 5, Characterized in that: At least two of the insulating joints are evenly arranged on the signal cable.

8. A multi-terminal grounding system for a signal cable, comprising a signal device, a control device, and a signal cable. The signal cable is a new type of multi-point grounding cable according to any one of claims 1-4. Characterized in that: The control device is connected to the signal device through the signal cable.

Images