Bending-resistant overhead insulated wire and method

Abstract

The invention discloses a bending-resistant overhead insulated wire, which comprises a steel core wire, a conductor, a filler, an insulating skin and an outer sheath, and is characterized in that a resistive layer is arranged between the insulating skin and the outer sheath; the two ends of the resistive layer of the bent section are connected to a power supply, and the resistive layer can uniformly heat the insulating skin and the outer sheath of the bent section. The invention also discloses a bending method of the overhead insulated wire, which is used for bending the bending-resistant overhead insulated wire. According to the bending-resistant overhead insulated wire and the method, the resistive layer is additionally arranged between the insulating skin and the outer sheath, and bending is performed after heating through the resistive layer, so that the bending residual stress is reduced, and the cracking condition of the bending part is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of power transmission and distribution overhead wires, and in particular to a bending-resistant overhead insulated wire and a method. Background Art

[0002] Overhead insulated conductors, also known as overhead cables, usually include steel core wires, conductors, fillers, insulation and outer sheaths, and have good tensile and insulation properties. Overhead insulated conductors need to be bent at waterproof bends to avoid buildings or obstacles, corner poles and lower leads. Generally speaking, the outer sheath is generally made of polyvinyl chloride plastic, which has good weather resistance. However, when the bending angle is large or the bending radius is small, the insulation and outer sheath will produce large residual bending stress at the cold-formed bend. Long-term exposure to cold outdoor environments and alternating hot and cold conditions will most likely cause cracks and cracks. The cracks are located at the lower part of the bend, which is susceptible to further corrosion by rainwater, thus affecting the safe operation of the overhead insulated conductors. Summary of the invention

[0003] The purpose of the present invention is to provide a bending-resistant overhead insulated conductor, in which a resistance layer is added between the insulating skin and the outer sheath, and the conductor is bent after being heated through the resistance layer, thereby reducing the bending residual stress and cracking at the bending portion.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The invention discloses a bending-resistant overhead insulated conductor, comprising a steel core wire, a conductor, a filler, an insulating skin and an outer sheath, wherein a resistance layer is arranged between the insulating skin and the outer sheath; a power source is connected to both ends of the resistance layer of the bending section, and the resistance layer can uniformly heat the insulating skin and the outer sheath of the bending section.

[0006] Furthermore, the resistance layer is attached to the outer wall of the insulating skin by a coating process, and the resistance layer is made of a mixture of graphite powder and resin polymer.

[0007] Furthermore, the resistance layer is made of a long conductive polymer sheet wound on the outer wall of the insulating skin.

[0008] The present invention also discloses a method for bending an overhead insulated conductor, which is to bend the bending-resistant overhead insulated conductor described in any one of the above items, comprising the following steps:

[0009] S1. Determine the bending section of the bending-resistant overhead insulated conductor and mark both ends;

[0010] S2, connecting two output leads of the handheld power supply device to the marked positions of the bending section respectively by puncture method, so that the resistance layer of the bending section is electrified;

[0011] S3. When the surface temperature of the outer sheath of the bending section reaches the set requirement, the power supply device stops outputting and removes the lead wire; and the bending section is thermally bent.

[0012] Furthermore, the auxiliary device used in step S2 also includes a clamp and a rotating member, the two clamps are respectively tightened at the marked positions of the bending section, and the clamps are electrically connected to the lead; the clamps are formed by two semicircular rings buckled and installed together through bolts on the butt flanges at both ends; a threaded sleeve is radially arranged on the clamp, and the rotating member is threadedly connected in the threaded sleeve, and a piercing needle portion is arranged on the inner end of the rotating member facing the outer sheath, and the piercing needle portion can pierce the outer sheath to electrically connect to the resistance layer.

[0013] Furthermore, it also includes a conductive gasket, which is pressed onto the through-bolt on the edge of the butt flange, and the conductive gasket is welded to the lead.

[0014] Furthermore, the three threaded sleeves are evenly distributed on the clamp body, and the number of the corresponding rotating parts is also three.

[0015] Furthermore, a slot for a flat-head or cross screwdriver is provided at the top of the rotating member.

[0016] Furthermore, an outer skirt is arranged on the outer periphery of the top end of the rotating member, and the bottom end of the outer skirt is coaxially sleeved outside the threaded sleeve; a ruler with scale lines is arranged on the outer wall of the threaded sleeve.

[0017] Furthermore, the method further comprises step S4 being arranged after step S3: S4, after the bending is completed, a protective clamping seat is used to seal and protect the puncture position of the puncture needle part.

[0018] Compared with the prior art, the beneficial technical effects of the present invention are:

[0019] The bending-resistant overhead insulated conductor of the present invention can also play the role of a shielding layer to a certain extent by arranging a resistance layer between the insulating skin and the outer sheath, and has an anti-interference effect; by applying electricity to both ends of the resistance layer of the bending section, the insulating skin and the outer sheath at the corresponding parts can be heated evenly, and the heat is naturally cooled after hot bending, which greatly reduces the bending residual stress compared to cold bending, and reduces the cracking of the insulating skin and the outer sheath at the bending point, which is especially suitable for cold areas. In addition, by using a coating process to process the resistance layer, a resistance layer with a relatively uniform thickness can be obtained, so that the insulating skin and the outer sheath are evenly heated. By making the resistance layer through a winding process, the step of drying after coating is avoided, the degree of modification of the existing production line of the overhead insulated conductor is reduced, and it is easier to be accepted by manufacturers.

[0020] The invention discloses an overhead insulated conductor bending method, which introduces the voltage and current of the power supply equipment at both ends of the bending section by the puncture method, minimizes the damage to the outer sheath, and almost negligible the bad influence. The temperature is reasonably set, and the bending is performed when the PVC outer sheath layer of the bending section just begins to soften, which will not affect the thickness of the outer sheath, and the bending will not cause residual stress. The setting of the clamp facilitates the clamp to be tightened to the marked position of the bending section to form a fixed support structure, thereby facilitating the puncture of the puncture needle. By coaxially arranging the puncture needle at the inner end of the rotating member, it is convenient to control the puncture depth of the puncture needle by the number of rotations. By arranging the conductive gasket, the lead connection of the power supply equipment is completed while the buckle installation of the clamp is completed, thereby improving the working efficiency. By arranging three sets of threaded sleeves and rotating members evenly distributed on the clamp body, the voltage and current can be evenly applied within the circumference of the overhead insulated conductor, ensuring that the resistance layer of the bending section is evenly energized and evenly heated. By arranging a slot for a flat or cross screwdriver at the top of the rotating member, it is convenient to use a tool to rotate the rotating member. Through the cooperation of the outer skirt and the ruler, it is convenient to control the penetration depth of each puncture needle to avoid excessive penetration and non-contact with the resistance layer. In order to prevent cracks from deriving from the puncture hole, the installation of a protective protective clamp can overcome this defect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the cross section of the bending-resistant overhead insulated conductor of the present invention;

[0023] Figure 2 It is a schematic diagram of heating the bending-resistant overhead insulated wire before bending according to the present invention;

[0024] Figure 3 It is a schematic cross-sectional view of the installation position of the clamp of the bending-resistant overhead insulated conductor of the present invention;

[0025] Figure 4 It is a partial cross-sectional schematic diagram of the installation part of the rotating member of the present invention;

[0026] Figure 5 It is a schematic diagram of the bending-resistant overhead insulated conductor of the present invention after being bent.

[0027] Explanation of the reference numerals: 1. Steel core wire; 2. Conductor; 3. Filler; 4. Insulation skin; 5. Resistance layer; 6. Outer sheath; 7. Clamp; 701. Butt flange edge; 702. Threaded sleeve; 703. Scale; 8. Rotating part; 801. Needle part; 802. Outer skirt; 9. Conductive gasket; 10. Power supply equipment; 11. Protective clamping seat. DETAILED DESCRIPTION

[0028] The core of the present invention is to provide a bending-resistant overhead insulated conductor and method, in which a resistance layer is added between the insulating skin and the outer sheath, and the conductor is bent after being heated through the resistance layer, thereby reducing the bending residual stress and cracking at the bending point.

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are 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 on the present invention.

[0031] With reference to the accompanying drawings, Figure 1 It is a schematic diagram of the cross section of the bending-resistant overhead insulated conductor of the present invention; Figure 2 It is a schematic diagram of heating the bending-resistant overhead insulated wire before bending according to the present invention; Figure 3 It is a schematic cross-sectional view of the installation position of the clamp of the bending-resistant overhead insulated conductor of the present invention; Figure 4 It is a partial cross-sectional schematic diagram of the installation part of the rotating member of the present invention; Figure 5 It is a schematic diagram of the bending-resistant overhead insulated conductor of the present invention after being bent.

[0032] Example 1

[0033] like Figure 1 and Figure 3 As shown, the bending-resistant overhead insulated conductor of the present invention comprises a steel core wire 1, a conductor 2, a filler 3, an insulating skin 4 and an outer sheath 6. The conductor 2 is a copper or aluminum multi-core twisted wire, and a plurality of conductors 2 are evenly distributed around the periphery of the steel core wire 1. The filler 3 is made of mica or asbestos and is filled in the insulating skin 4. The important difference between the bending-resistant overhead insulated conductor of the present invention and the existing overhead insulated conductors is that a resistance layer 5 is also provided between the insulating skin 4 and the outer sheath 6 of the present invention. The bending position of the bending-resistant overhead insulated conductor of the present invention is defined as a bending section, and a power source is connected to both ends of the resistance layer 5 of the bending section. After the resistance layer 5 is energized, it can evenly heat the insulating skin 4 and the outer sheath 6 of the bending section.

[0034] By arranging the resistance layer 5 between the insulating skin 4 and the outer sheath 6, it can also play the role of a shielding layer to a certain extent, and have an anti-interference effect; by applying electricity to the two ends of the resistance layer 5 of the bending section, the insulating skin 4 and the outer sheath 6 at the corresponding parts can be heated, and the heat is evenly distributed, and then naturally cooled after hot bending. Compared with cold bending, the bending residual stress is greatly reduced, and the cracking of the insulating skin 4 and the outer sheath 6 at the bending point is reduced, which is especially suitable for cold areas.

[0035] In a specific implementation of this embodiment, the resistance layer 5 is attached to the outer wall of the insulating skin 4 by a coating process. The resistance layer 5 is made of a paste material mixed with graphite powder and resin polymer. When the overhead insulated conductor semi-finished product passes through the paste material coating tank, the coating of the resistance layer 5 is completed and then dried.

[0036] Specifically, the ratio of graphite powder to resin polymer varies according to the design requirements of the resistance value per meter, and the specific ratio needs to be confirmed after experimental measurement.

[0037] By processing the resistor layer 5 using a coating process, a resistor layer 5 with a relatively uniform thickness can be obtained, so that the insulating skin 4 and the outer sheath 6 are evenly heated.

[0038] In a specific implementation of this embodiment, the resistance layer 5 is made of a long conductive polymer sheet wound on the outer wall of the insulating skin 4, and this process is similar to the winding of the shielding layer with aluminum foil.

[0039] The resistor layer 5 is manufactured by the winding process, thereby avoiding the step of drying after coating, reducing the degree of modification of the existing production line of the overhead insulated conductor, and being more easily accepted by manufacturers.

[0040] Example 2

[0041] The present invention also discloses a method for bending an overhead insulated conductor. Figure 2 As shown, bending the bending-resistant overhead insulated conductor of any of the above embodiments comprises the following steps:

[0042] S1. Determine the bending section of the bending-resistant overhead insulated conductor, and mark both ends of the bending section with a marking pen.

[0043] S2, connect the two output leads of the handheld power supply device 10 to the marked positions of the bending section by puncture method, so that the resistance layer 5 of the bending section is powered. The power supply device 10 generally outputs 12V or 24V DC power.

[0044] S3. Check that the surface temperature of the outer sheath 6 of the bending section reaches the set requirement, which is generally set to 80-85° C. The power supply device 10 stops outputting and removes the lead wire; the bending section is thermally bent in a hot state, and the bent state is maintained for natural cooling.

[0045] The voltage and current of the power supply device 10 are introduced into the two ends of the bending section by the puncture method, which causes the least damage to the outer sheath 6 and almost negligible bad influence. The temperature is reasonably set, and the bending is performed when the PVC outer sheath layer of the bending section just begins to soften, which will not affect the thickness of the outer sheath 6, and there will be no residual stress in the bending.

[0046] In a specific implementation of this embodiment, Figure 2 and Figure 3 As shown, the auxiliary device used in step S2 also includes a clamp 7 and a rotating member 8. The two clamps 7 are respectively tightened at the marked positions of the bending section, and the clamps 7 are electrically connected to the positive and negative leads of the power supply device 10. The clamp 7 is formed by two semicircular rings buckled and installed together by connecting bolts through the butt flange edges 701 at both ends. A threaded sleeve 702 is radially arranged on the clamp 7, and the root of the threaded sleeve 702 is directly welded on the outer wall of the clamp 7 body, and the clamp 7 body is provided with a clearance hole at the middle hole position of the threaded sleeve 702. The screw body of the rotating member 8 is threadedly connected in the threaded sleeve 702, and the rotating member 8 is coaxially and integrally provided with a piercing needle portion 801 toward the inner end of the outer sheath 6. The head of the piercing needle portion 801 is in the shape of a spike, and the piercing needle portion 801 can pierce the outer sheath 6 to electrically connect the resistance layer 5.

[0047] By setting the clamp 7, it is convenient to clamp to the marked position of the bending section to form a fixed support structure, thereby facilitating the puncture of the puncture needle 801. By coaxially setting the puncture needle 801 at the inner end of the rotating member 8, it is convenient to control the puncture depth of the puncture needle 801 by the number of rotations.

[0048] In a specific implementation of this embodiment, Figure 2 and Figure 3 As shown, the auxiliary device used in step S2 also includes a conductive gasket 9, which is pressed onto the through-bolt of the butt flange edge 701, and the conductive gasket 9 is welded to the lead terminal of the power supply device 10.

[0049] By providing the conductive gasket 9, the lead connection of the power supply device 10 is completed while the buckle installation of the clamp 7 is completed, thereby improving the operation efficiency.

[0050] In a specific implementation of this embodiment, Figure 2 and Figure 3 As shown, three threaded sleeves 702 are evenly distributed on the hoop 7 body, and the number of corresponding rotating members 8 is also three. The threaded sleeves 702 and the rotating members 8 are arranged one by one.

[0051] Specifically, if Figure 2 and Figure 4 As shown, a slot for a slotted screwdriver or a cross screwdriver is provided at the top of the rotating member 8 .

[0052] Specifically, if Figure 2 and Figure 4 As shown, an outer skirt 802 is provided at the outer periphery of the top of the rotating member 8, and the bottom end of the outer skirt 802 is coaxially buckled outside the threaded sleeve 702. A scale 703 with scale lines is provided on the outer wall of the threaded sleeve 702. The penetration depth of the puncture needle 801 can be determined by observing the overlap position of the bottom edge of the outer skirt 802 and the scale 703.

[0053] By evenly distributing three sets of threaded sleeves 702 and rotating parts 8 on the main body of the clamp 7, voltage and current can be evenly applied within the circumference of the overhead insulated wire to ensure that the resistance layer 5 of the bending section is evenly energized and heated. By providing a slot for a flat or cross screwdriver at the top of the rotating part 8, it is convenient to use a tool to rotate the rotating part 8. Through the cooperation of the outer skirt 802 and the ruler 703, it is convenient to control the penetration depth of each needle part 801 to avoid excessive penetration and non-contact with the resistance layer 5.

[0054] In a specific implementation of this embodiment, Figure 5 As shown, the overhead insulated conductor bending method of the present invention further includes step S4 arranged after step S3: S4, after the bending is completed, the protective clamping seat 11 is used to seal and protect the puncture position of the puncture needle part 801.

[0055] Figure 5 The bending angle of the bending section shown in the figure is 90 degrees, which is only used as an example. The protective clamping seat 11 can be installed at both ends at any other bending angle, and the content of the drawings shall not be regarded as limiting the scope of protection of this application.

[0056] Specifically, if Figure 5 As shown, the protective card holder 11 is fastened by two half-ring shells and then screwed and locked, and at least two screws are used on each side of the flange edges at both ends for locking. The protective card holder 11 is made of rubber or plastic.

[0057] In fact, the diameter of the small hole punctured by the puncture needle part 801 is not more than 1 mm, and after the puncture needle part 801 is withdrawn, it can almost be closed under the elastic reset of the outer sheath 6 material. However, in order to prevent cracks from being derived here, the protective protective card holder 11 can overcome this defect.

[0058] In summary, the bending-resistant overhead insulated conductor of the present invention can also play the role of a shielding layer to a certain extent by setting a resistance layer 5 between the insulating skin 4 and the outer sheath 6, and has an anti-interference effect; by applying electricity to both ends of the resistance layer 5 of the bending section, the insulating skin 4 and the outer sheath 6 of the corresponding parts can be heated evenly, and the heat is naturally cooled after hot bending, which greatly reduces the bending residual stress compared to cold bending, and reduces the cracking of the insulating skin 4 and the outer sheath 6 at the bending point, which is especially suitable for cold areas. In addition, by using a coating process to process the resistance layer 5, a resistance layer 5 with a relatively uniform thickness can be obtained, so that the insulating skin 4 and the outer sheath 6 are evenly heated. By making the resistance layer 5 through a winding process, the step of drying after coating is avoided, the degree of modification of the existing production line of the overhead insulated conductor is reduced, and it is easier to be accepted by manufacturers.

[0059] The overhead insulated wire bending method of the present invention uses a puncture method to introduce the voltage and current of the power supply device 10 at both ends of the bending section, which minimizes the damage to the outer sheath 6 and almost negligible bad effects. Reasonably set the temperature, and bend when the PVC outer sheath layer of the bending section just begins to soften, which will not affect the thickness of the outer sheath 6, and the bending will not have residual stress. Through the setting of the clamp 7, it is convenient to tighten the clamp to the marked position of the bending section to form a fixed support structure, and then it is convenient to complete the puncture of the puncture part 801. By coaxially setting the puncture part 801 at the inner end of the rotating member 8, it is convenient to control the penetration depth of the puncture part 801 by the number of rotations. Through the setting of the conductive gasket 9, the lead connection of the power supply device 10 is completed while completing the buckle installation of the clamp 7, thereby improving the working efficiency. By evenly arranging three sets of threaded sleeves 702 and rotating members 8 on the clamp 7 body, voltage and current can be evenly applied within the circumference of the overhead insulated wire, ensuring that the resistance layer 5 of the bending section is evenly energized and evenly heated. By providing a slot for a flat-head or cross-head screwdriver at the top of the rotating member 8, it is convenient to use a tool to rotate the rotating member 8. Through the cooperation of the outer skirt 802 and the scale 703, it is convenient to control the penetration depth of each puncture needle part 801 to avoid excessive penetration and non-contact with the resistance layer 5. In order to prevent cracks from being derived from the puncture hole, the protective protective clamp seat 11 can be added to overcome this defect.

[0060] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0061] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A bending-resistant overhead insulated conductor, comprising a steel core wire (1), a conductor (2), a filler (3), an insulating skin (4) and an outer sheath (6), characterized in that: A resistance layer (5) is also provided between the insulating skin (4) and the outer sheath (6); a power source is connected to both ends of the resistance layer (5) of the bending section, and the resistance layer (5) can evenly heat the insulating skin (4) and the outer sheath (6) of the bending section.

2. The bending-resistant overhead insulated conductor according to claim 1, characterized in that: The resistance layer (5) is attached to the outer wall of the insulating skin (4) by a coating process, and the resistance layer (5) is made of a mixture of graphite powder and resin polymer.

3. The bending-resistant overhead insulated conductor according to claim 1, characterized in that: The resistance layer (5) is made of a long conductive polymer sheet wound on the outer wall of the insulating skin (4).

4. A method for bending an overhead insulated conductor, characterized in that: Bending the bend-resistant overhead insulated conductor according to any one of claims 1 to 3 comprises the following steps: S1. Determine the bending section of the bending-resistant overhead insulated conductor and mark both ends; S2, connecting two output leads of the handheld power supply device (10) to the marked positions of the bending section respectively by puncturing, so that the resistance layer (5) of the bending section is electrified; S3. When the surface temperature of the outer sheath (6) of the bending section reaches the set requirement, the power supply device (10) stops outputting and removes the lead wire; and the bending section is thermally bent.

5. The method for bending an overhead insulated conductor according to claim 4, characterized in that: The auxiliary device used in step S2 also includes a clamp (7) and a rotating member (8), the two clamps (7) are respectively clamped at the marked positions of the bending section, and the clamps (7) are electrically connected to the lead wire; the clamps (7) are formed by two semicircular rings buckled together and are installed together by bolts through the butt flange edges (701) at both ends; a threaded sleeve (702) is radially arranged on the clamp (7), and the rotating member (8) is threadedly connected in the threaded sleeve (702); the rotating member (8) is provided with a piercing needle part (801) at the inner end facing the outer sheath (6), and the piercing needle part (801) can pierce the outer sheath (6) to electrically connect the resistance layer (5).

6. The method for bending an overhead insulated conductor according to claim 5, characterized in that: It also includes a conductive gasket (9), which is pressed tightly onto the through-bolt of the butt flange edge (701), and the conductive gasket (9) is welded to the lead wire.

7. The method for bending an overhead insulated conductor according to claim 5, characterized in that: The three threaded sleeves (702) are evenly distributed on the circumference of the clamp (7) body, and the number of the corresponding rotating parts (8) is also three.

8. The method for bending an overhead insulated conductor according to claim 7, characterized in that: The top end of the rotating member (8) is provided with a slot for a slotted screwdriver or a cross screwdriver.

9. The method for bending an overhead insulated conductor according to claim 8, characterized in that: An outer skirt (802) is arranged on the periphery of the top end of the rotating member (8), and the bottom end of the outer skirt (802) is coaxially sleeved outside the threaded sleeve (702); a ruler (703) with scale lines is arranged on the outer wall of the threaded sleeve (702).

10. The method for bending an overhead insulated conductor according to claim 5, characterized in that: The method further comprises a step S4 arranged after the step S3: S4, after the bending is completed, a protective clamping seat (11) is used to seal and protect the puncture position of the puncture needle part (801).

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