A power cable and plastic protective tube thereof

Abstract

The present invention relates to the field of power cables, and specifically provides a power cable and a plastic protective tube thereof, wherein the power cable comprises a cable body, the plastic protective tube comprises two conductors arranged in parallel on the cable body, a plurality of fixtures for fixing the conductors on the cable body and equidistantly distributed, and a plastic protective layer formed on the cable body and wrapping the conductors and the fixtures; at least part of the fixture is a conductor, and the two conductors corresponding to the position of each fixture are electrically connected through the conductor. The present invention has low cost, high production efficiency, and can quickly locate the damaged position of the power cable.

Description

Technical Field

[0001] The invention relates to the field of power cables, in particular to a power cable and a plastic protection tube thereof. Background Art

[0002] Cable is a device for transmitting electric energy or signals, usually composed of several or several groups of wires. After being laid out, the cable needs to work stably for a long time. However, when affected by the environment, the cable is easily damaged, affecting life and production. Therefore, when the cable is damaged, it is necessary to promptly determine the location of the damaged cable so as to repair it and reduce the loss.

[0003] At present, the location of damaged cables is mainly checked and located by manpower, which is extremely inefficient. During the inspection process, the corresponding life and production will be affected. Based on the above situation, some manufacturers use signal detection to quickly and accurately locate the damaged cable. For example, the patent specification with the publication number CN118471600A discloses an elevator cable with a fault location detection function, including a fault detection line, which is an optical fiber signal line. The optical fiber signal line is electrically connected to the monitor of the elevator room. The fault detection line is integrated with a sensor, and the sensor is placed every 1-3 meters. This solution is to quickly locate the fault position through a sensor. However, locating the fault position through a sensor is only applicable to short-distance cables, and is not applicable to long-distance cables, because a large number of sensors need to be arranged for long-distance cables, which is costly. At the same time, placing a large number of sensors in the cable will greatly reduce production efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide a power cable and its plastic protective tube with low cost, high production efficiency, and the ability to quickly locate the damaged position in order to address the current problem that it is impossible to quickly locate the damaged position of long-distance cables.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A plastic protective tube for a power cable, the power cable comprising a cable body, the plastic protective tube comprising two conductors arranged in parallel on the cable body, a plurality of fixtures for fixing the conductors on the cable body and equidistantly distributed, and a plastic protective layer formed on the cable body and wrapping the conductors and the fixtures; at least a portion of the fixtures is a conductor, and the two conductors are electrically connected via the conductor at the position of each fixture.

[0007] In this solution, two parallel conductors are arranged on the cable body, and the conductors are fixed by equidistantly arranged fixing members. The two conductors are electrically connected at the corresponding position of each fixing member, that is, a plurality of conductors with the same resistance are connected in parallel between the two conductors.

[0008] When the cable body is damaged and fails, the wires will also break. At this time, the circuit is connected from the same end of the two wires, and the resistance between the two wires is detected. The resistance at this time is the resistance of the two wires and the resistance of the conductor in parallel between the two wires. After that, the number of conductor resistances is calculated to determine the location of the cable damage, which is convenient for quick repair.

[0009] In one embodiment, the two conductors are spirally wound around the cable body.

[0010] The spiral winding structure is more adaptable to the bending deformation of the cable, avoiding the wire breakage caused by the normal bending deformation of the cable, which affects the subsequent confirmation of the damage location after the cable is actually damaged.

[0011] In one embodiment, the cross-sectional diameter of the cable body is D, the projection distance of the two conductors in the plane is d, and 0.5D≤d≤D.

[0012] The above design can increase the range of wire detection, so that no matter where the cable is damaged, the wire can be broken accordingly, avoiding the situation where the cable is damaged but the wire is not broken because the wire distance is set too small.

[0013] In one embodiment, the fixing member is a spiral ring conductor with one spiral turn, and at least one end surface of the spiral ring conductor is an insulating surface.

[0014] The spiral ring structure avoids the abutment of the two end faces of the fixing piece, which causes the clamping force on the wire to be too small, that is, it ensures the clamping force of the conductor on the cable and ensures the contact between the conductor and the wire; the fixing piece has sufficient clamping force on the cable, and when the cable body is subsequently coated with a plastic protective layer, it can effectively reduce the axial relative movement of the plastic protective layer and the cable body, and increase the bonding degree between the plastic protective layer and the cable body.

[0015] At the same time, at least one end surface of the spiral ring conductor is an insulating surface to avoid electrical conduction between the two ends, thereby avoiding the occurrence of two sections of resistance corresponding to the same fixing position, resulting in different resistances of fixings at different positions, which affects the detection results.

[0016] In one embodiment, the fixing member is in the shape of a closed ring, and the fixing member in the shape of a ring contacts the two conductors to form two contact points, and the two contact points divide the circumference of the cable body at corresponding positions into a first part and a second part;

[0017] The area of ​​the fixing member corresponding to the first part is a conductor, and the arc length of the conductor is greater than the arc length of the first part, or the area of ​​the fixing member corresponding to the second part is a conductor, and the arc length of the conductor is greater than the arc length of the second part.

[0018] The design of the arc length of the conductor leaves a deviation margin for the installation of the fixing part, so as to avoid the situation where the arc length of the conductor is too short to achieve electrical conduction between the two wires after the fixing part is installed at a small offset distance.

[0019] In one embodiment, the width of the fixing element is 0.5-1.5 cm.

[0020] This size design ensures the fixing effect of the fixing piece on the wire, while ensuring reliable contact between the conductor and the wire.

[0021] In one embodiment, the conductor is made of iron, chromium or titanium.

[0022] The resistivity of iron, chromium and titanium is relatively large. Under the same conditions, the resistance values ​​of iron, chromium and titanium are relatively high, which is more convenient for the subsequent calculation of the resistance value and the determination of the number of conductors.

[0023] In one embodiment, the plastic protective layer is made of polyethylene, polypropylene, polyvinyl chloride or polytetrafluoroethylene.

[0024] In one embodiment, the two conductors are spirally wound around the cable body by a wire winding device.

[0025] In one embodiment, the plastic protective layer is formed on the cable body by extrusion equipment.

[0026] The present invention also provides a power cable, which is protected by the above-mentioned plastic protection tube.

[0027] The beneficial effects of the present invention are:

[0028] The plastic protective tube for power cables provided by the present invention only comprises two conductors, a plurality of fixings and a plastic protective layer, and the materials are easily available and inexpensive; during production, it is only necessary to first arrange the two conductors in parallel on the power cable using a plurality of fixings, and then form a plastic protective layer on the outside, and the processing is simple. After forming, the conductors, the fixings and the plastic protective layer become one, and together form a protective tube for the power cable, which plays a protective role for the power cable; during detection, it is only necessary to connect the circuit from the same end of the two conductors, and detect the resistance between the two conductors, and then calculate the amount of conductor resistance, so as to determine the location of the cable damage, and the operation is simple and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of the molded plastic protective tube on the power cable of the present invention;

[0030] Figure 2 It is a top view of the molded plastic protective tube on the power cable of the present invention;

[0031] Figure 3 It is a side view of the molded plastic protective tube on the power cable of the present invention;

[0032] Figure 4 It is a schematic diagram of the structure of arranging conductors and fixing parts on the power cable of the present invention;

[0033] Figure 5 A top view of the arrangement of conductors and fixings on the power cable of the present invention;

[0034] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0035] Figure 7 An equivalent circuit diagram of the circuit formed by the wires and the fixings;

[0036] Among them: 101, copper core; 102, conductor shielding layer; 103, insulation layer; 104, insulation shielding layer; 105, anti-corrosion layer; 106, wire; 107, fixing part; 1071, insulation surface; 108, plastic protective layer; 109, tensile steel cable; 110, fireproof material. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0040] like Figure 1-6 As shown, a plastic protective tube for a power cable, the power cable includes a cable body, the plastic protective tube includes two conductors 106 arranged in parallel on the cable body, a plurality of fixings 107 for fixing the conductors 106 on the cable body and equidistantly distributed, and a plastic protective layer 108 formed on the cable body and wrapping the conductors 106 and the fixings 107; at least a portion of the fixings 107 is a conductor, and the two conductors 106 are electrically connected via the conductor at the position corresponding to each fixing 107.

[0041] During production, two conductors 106 are first arranged in parallel on the power cable using a plurality of fixings 107, and then a plastic protective layer 108 is formed on the outside; after forming, the conductors 106, the fixings 107 and the plastic protective layer 108 become one body, together forming a plastic protective tube for the power cable, which plays a protective role for the power cable.

[0042] The power cable of the present application can be a cable of any structure, and no specific limitation is made here. Only one cable structure is introduced below. Figure 1-3 As shown, the cable body includes three groups of copper cores 101, each group of copper cores 101 is coated with a conductor shielding layer 102, the conductor shielding layer 102 is coated with an insulating layer 103, the insulating layer 103 is coated with an insulating shielding layer 104, the three groups of insulating shielding layers 104 are coated with an anti-corrosion layer 105 as a whole, the anti-corrosion layer 105 and the insulating shielding layer 104 are filled with fire-proof material 110, and a tensile steel cable 109 is also arranged inside the cable body.

[0043] In some embodiments, Figure 4-6 As shown, two conductors 106 are spirally wound on the anti-corrosion layer 105 of the cable body. The spiral winding structure can better adapt to the bending deformation of the cable, avoiding the normal bending deformation of the cable causing the conductor 106 to break, which affects the subsequent confirmation of the damage position after the cable is actually damaged. The spiral winding method preferably uses a wire winding device, which has a high winding rate and can ensure the parallelism of the two conductors 106, further making the parallel conductor resistance between the two conductors 106 consistent, which is convenient for the subsequent calculation of the number of conductors.

[0044] In some embodiments, the cross-sectional diameter of the cable body is D, the projection distance of the two conductors 106 in the plane is d, and 0.5D≤d≤D. The spiral winding design and the large span design of the conductor increase the detection range of the conductor 106, so that no matter where the cable is damaged, the conductor 106 can be broken, avoiding the situation where the cable is damaged but the conductor 106 is not broken because the distance between the conductors 106 is too small.

[0045] In the present application, the structure of the fixing member 107 is not specifically limited, as long as at least part of the fixing member 107 is a conductor, when fixing the two wires 106, the conductor part of the fixing member 107 can electrically connect the two corresponding wires 106. Preferably, the structure of the fixing member 107 can adopt the following two implementations.

[0046] Implementation 1: The fixing member 107 is a spiral ring conductor with 1 spiral turn, and at least one end surface of the spiral ring conductor is an insulating surface 1071. The spiral ring structure avoids the abutment of the two end surfaces of the fixing member 107, resulting in too small a pressing force on the wire 106, that is, it ensures the pressing force of the conductor on the cable, and ensures that the conductor is in contact with the wire 106; the fixing member 107 has sufficient clamping force on the cable body, and when the cable body is subsequently coated with the plastic protective layer 108, it can effectively reduce the axial relative movement of the plastic protective layer 108 and the cable body, and increase the bonding degree of the plastic protective layer 108 and the cable body. At the same time, at least one end surface of the spiral ring conductor is an insulating surface 1071, which avoids electrical conduction between the two ends and avoids the occurrence of two sections of resistance corresponding to the same fixing member 107 position, resulting in different resistances of the fixing member 107 at different positions, which affects the detection results.

[0047] Embodiment 2: The fixing member 107 is in the shape of a closed ring. The ring-shaped fixing member 107 contacts the two wires 106 to form two contact points. The two contact points divide the circumference of the cable body at the corresponding position into a first part and a second part. The area of ​​the fixing member 107 corresponding to the first part is a conductor, and the arc length of the conductor is greater than the arc length of the first part, or the area of ​​the fixing member 107 corresponding to the second part is a conductor, and the arc length of the conductor is greater than the arc length of the second part. Here, the arc length of the first part is not less than the arc length of the second part. Only when the two wires 106 are wound along the opposite side walls of the cable body, that is, when d=D, the arc length of the first part is equal to the arc length of the second part. When 0.5D≤d<D, the arc length of the first part is greater than the arc length of the second part. For economic reasons, the area of ​​the fixing member 107 corresponding to the second part is preferably a conductor, in which case the length of the conductor part can be made shorter; here it is necessary to make the arc length of the conductor part greater than the arc length of the second part. This design can leave a deviation margin for the installation of the fixing member 107 to avoid the situation where the arc length of the conductor part is too short to achieve electrical conduction between the two wires 106 after the fixing member 107 is installed at a small offset distance.

[0048] In some embodiments, the width of the fixing member 107 is 0.5-1.5 cm, preferably 1 cm. This size design ensures the fixing effect of the fixing member 107 on the wire 106 and ensures reliable contact between the conductor and the wire 106.

[0049] In some embodiments, the conductor is made of iron, chromium or titanium. The resistivity of iron, chromium and titanium is relatively large, and the resistance values ​​of iron, chromium and titanium are relatively high under the same conditions, which is more convenient for subsequent calculation of the resistance value and determination of the number of conductors.

[0050] In some embodiments, the material of the plastic protective layer 108 is polyethylene, polypropylene, polyvinyl chloride or polytetrafluoroethylene. After the cable body is produced, the wire 106 is wound on the surface of the anti-corrosion layer 105 using a wire winding device, and then the fixing piece 107 is stuck on the anti-corrosion layer 105 at the same interval to fix the wire 106. Then, the cable body with the wire 106 and the fixing piece 107 is passed through an extruder, and the plastic protective layer 108 is added to the cable body. At the same time, the wire 106 and the fixing piece 107 are wrapped. The wire 106, the fixing piece 107 and the plastic protective layer 108 finally become one, forming a plastic protective tube to protect the cable body.

[0051] When the cable body is damaged and fails, the wire 106 will also break. At this time, the circuit is connected from the same end of the two wires 106, and the resistance between the two wires 106 is detected. The resistance at this time is the resistance of the two wires 106 and the conductor resistance in parallel between the two wires 106. The equivalent circuit diagram of the circuit formed by the wire 106 and the fixing member 107 (conductor) is as follows: Figure 7 As shown, by calculating the conductor resistance, the location of the cable damage can be determined, facilitating quick repairs.

[0052] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-described embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A plastic protective tube for a power cable, the power cable comprising a cable body, characterized in that: The plastic protective tube includes two conductors arranged in parallel on the cable body, a plurality of fixing parts used to fix the conductors on the cable body and distributed equidistantly, and a plastic protective layer formed on the cable body and wrapping the conductors and the fixing parts; at least a portion of the fixing parts is a conductor, and the two conductors corresponding to the position of each fixing part are electrically connected through the conductor.

2. The power cable plastic protection tube according to claim 1, characterized in that: The two conducting wires are spirally wound on the cable body.

3. The plastic protective tube for power cables according to claim 1 or 2, characterized in that: The cross-sectional diameter of the cable body is D, the projection distance of the two conductors in the plane is d, and 0.5D≤d≤D.

4. The plastic protective tube for power cables according to claim 1, characterized in that: The fixing member is a spiral ring conductor with one spiral turn, and at least one end surface of the spiral ring conductor is an insulating surface.

5. The plastic protective tube for power cables according to claim 1, characterized in that: The fixing member is in a closed ring shape, and the ring-shaped fixing member contacts the two wires to form two contact points, and the two contact points divide the circumference of the cable body at the corresponding position into a first part and a second part; The area of ​​the fixing member corresponding to the first part is a conductor, and the arc length of the conductor is greater than the arc length of the first part, or the area of ​​the fixing member corresponding to the second part is a conductor, and the arc length of the conductor is greater than the arc length of the second part.

6. The plastic protective tube for power cables according to claim 4 or 5, characterized in that: The width of the fixing piece is 0.5-1.5 cm.

7. The plastic protective tube for power cables according to claim 4 or 5, characterized in that: The conductor is made of iron, chromium or titanium.

8. The plastic protective tube for power cables according to claim 1, characterized in that: The material of the plastic protective layer is polyethylene, polypropylene, polyvinyl chloride or polytetrafluoroethylene.

9. The plastic protective tube for power cables according to claim 2, characterized in that: The two conductors are spirally wound on the cable body through a wire winding device.

10. A power cable, characterized in that: The power cable comprises the power cable plastic protection tube as claimed in any one of claims 1 to 9.

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