Power cable and installation equipment for reducing cable sheath cracking

Abstract

The application relates to the cable technical field, and particularly discloses a power cable capable of reducing cable outer skin cracking and installation equipment. The power cable capable of reducing cable outer skin cracking comprises a winding piece, a wire core and an insulation layer wrapped outside the wire core. The winding piece comprises a connecting rope, support pieces are fixed on the connecting rope at equal intervals, the connecting rope is spirally wound on the insulation layer, two adjacent support pieces in the axial direction of the insulation layer are staggered and overlapped, and the end of the support piece away from the connecting rope is in contact with the insulation layer. The winding piece is coated with an outer skin. The stress at the bending position of the power cable capable of reducing cable outer skin cracking is not concentrated on one point of the outer skin, so that the outer skin is prevented from cracking due to excessive stretching. During the movement of the power cable pulled by the installation equipment, the stress concentration of the outer skin is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to a power cable and installation equipment for reducing cable sheath cracking. BACKGROUND

[0002] Cross-linked polyethylene insulated power cables are important links connecting power stations, substations and users, and bear the task of transmitting electric energy from the power generation end to the power consumption end. The cross-linked polyethylene insulated power cable comprises one or more conductor cores, an insulation layer and a protective outer sheath.

[0003] In the existing cable production process, the sheath is directly extruded by an extruder die outside the insulation layer in a molten state, and then cooled and shaped. The sheath and the insulation layer are tightly attached together to form a compact structure.

[0004] During the bending process of the cable, the outer side of the sheath at the bending position is elongated and the inner side of the sheath at the bending position is compressed because the sheath and the insulation layer are relatively fixed. The deformation stress generated by bending cannot be effectively dispersed or released, but is completely borne by the sheath itself. Under the repeated bending action, the bending position of the sheath is fatigued, eventually exceeds the elastic limit and appears micro-cracks. These cracks gradually expand with the increase of the number of bending, eventually forming a break. The break in the sheath causes water from the outside to enter the inside of the cable, the insulation performance of the cable is sharply reduced, there is a risk of electrical short circuit, and the service life of the cable is shortened, increasing the maintenance and replacement costs. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the existing defects and provide a power cable and installation equipment for reducing cable sheath cracking. The stress at the bending position of the present power cable is not concentrated on one point of the sheath, avoiding the sheath cracking due to excessive stretching. The present installation equipment avoids stress concentration of the sheath during the movement of pulling the power cable.

[0006] The technical solution adopted by the present application to solve the technical problem comprises:

[0007] On the one hand, a power cable for reducing cable sheath cracking is provided, comprising a winding member, a core and an insulation layer wrapped outside the core. The winding member comprises a connecting rope, and support pieces are fixed on the connecting rope at equal intervals. The connecting rope is spirally wound on the insulation layer. Adjacent two support pieces in the axial direction of the insulation layer are staggered and overlapped, and the end of the support piece away from the connecting rope is in contact with the insulation layer. The winding member is covered with a sheath.

[0008] The ratio of the area of the support piece to the area of the overlapping part of the adjacent two support pieces in the axial direction of the insulation layer is 2.0-5.0:1.0.

[0009] As a preferred technical scheme of the present application, a containing cavity is formed between the outer sheath and the insulation layer, and the containing cavity is filled with a plugging liquid for repairing cracks in the outer sheath.

[0010] As a preferred technical scheme of the present application, a plurality of support pieces of the winding member are each provided with an opening.

[0011] As a preferred technical scheme of the present application, the long bag body is further spirally wound on the insulation layer, and the long bag body is fixedly connected with the connecting rope.

[0012] The long bag body has a folded state and an expanded state, the folded state of the long bag body has a first volume, and the expanded state of the long bag body has a second volume, the second volume being greater than the first volume.

[0013] The long bag body is filled with gas, and the long bag body is changed from the folded state to the expanded state.

[0014] As a preferred technical scheme of the present application, the plugging liquid is a sodium silicate solution or a borate ester flame-retardant liquid.

[0015] As a preferred technical scheme of the present application, the length of the support piece in the direction perpendicular to the connecting rope is 2.0-5.0 cm.

[0016] As a preferred technical scheme of the present application, the support piece is an elastic metal sheet or an elastic plastic sheet, and the connecting rope is a carbon fiber rope, a steel wire rope or a plastic soft rope.

[0017] In another aspect, a mounting device is also provided, which is used in combination with any of the power cables for reducing cracks in the outer sheath of the cable, and comprises a base, a rotating ring mounted on the base, a plurality of blocking pieces arranged at equal angles on the outer circumferential side of the ring, one end of an elastic clamping piece fixedly connected with the base, the other end of the elastic clamping piece close to the outer circumferential side of the ring, a plurality of rotating wheels mounted at equal angles on the inner circumferential side of the ring, and the included angle between the axis of the rotating wheel and the axis of the ring being less than 90°.

[0018] The ring comprises a long arc segment, and a short arc segment is mounted at the gap of the long arc segment.

[0019] The elastic clamping piece and the blocking piece cooperate to enable the ring to rotate only when the torque acting on the ring exceeds a set value.

[0020] As a preferred technical scheme of the present application, not less than two support rods are fixed on the base, or a clamping hook is fixed on the base and a positioning bolt is mounted on the clamping hook.

[0021] As a preferred technical scheme of the present application, the base is fixed with a bearing film at both ends.

[0022] One end of the long circular arc segment and the short circular arc segment are connected through a rotating connecting piece, and the other end of the long circular arc segment and the short circular arc segment are detachably connected through a limiting piece.

[0023] Compared with the prior art, the present application has the following advantages:

[0024] 1. The power cable for reducing cable sheath cracking provided by the present application, on the one hand, when the power cable is subjected to external forces such as bending, stretching, and twisting, the interleaved and stacked support pieces in the winding member can slide relative to each other, and the stress at the bending position of the power cable is not concentrated on a single point of the sheath, but is dispersed through the sliding of the interleaved and stacked support pieces, thereby avoiding the sheath from cracking due to excessive stretching; on the other hand, when the sheath cracks and a breach appears, the sealing liquid in the accommodation cavity flows to the outer circumferential side of the sheath through the breach, and the sealing liquid solidifies to seal the breach, thereby improving the service life of the power cable and reducing maintenance costs; on the other hand, the long bag body in the accommodation cavity changes from a folded state to an inflated state, and the liquid pressure of the sealing liquid in the accommodation cavity increases, so that when a breach appears on the sheath, the sealing liquid in the accommodation cavity flows out of the breach, and when multiple breaches appear on the sheath, the sealing liquid can seal multiple breaches, thereby improving the safety of the power cable and reducing the risk of accidents.

[0025] 2. The power cable for reducing cable sheath cracking provided by the present application, when the power cable is subjected to impact, the winding member absorbs and buffers a portion of the impact, thereby reducing the risk of damage to the core and the insulating layer.

[0026] 3. The installation device provided by the present application, during the movement of the power cable by pulling, the power cable swings horizontally, and the height of the power cable at the circular ring changes constantly, thereby avoiding stress concentration on the sheath. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 FIG. 1 is a partial cross-sectional structural schematic diagram of the power cable for reducing cable sheath cracking provided by the present application;

[0028] Figure 2 FIG. 2 is an enlarged schematic diagram of the structure at A of FIG. 1; Figure 1

[0029] Figure 3 FIG. 3 is a structural schematic diagram of the winding member of FIG. 1; Figure 1

[0030] Figure 4 FIG. 4 is a structural schematic diagram of one embodiment of the installation device provided by the present application;

[0031] Figure 5 FIG. 5 is a structural schematic diagram of another embodiment of the installation device provided by the present application; ​​

[0032] Figure 6 Another embodiment structure schematic diagram of installing the device of the present application.

[0033] In the figure: 1 outer skin, 2 support sheet, 3 connecting rope, 4 accommodating cavity, 5 opening, 6 wire core, 7 long bag body, 8 circular ring, 801 long circular arc segment, 802 blocking piece, 803 rotating connecting piece, 804 short circular arc segment, 805 limiting piece, 806 rotating wheel, 9 insulation layer, 10 base, 11 support rod, 12 bolt, 13 clamping hook, 14 bearing film, 15 elastic clamping piece. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0035] Embodiment one:

[0036] Please refer to Figures 1-3 The embodiment discloses a power cable capable of reducing cable outer skin cracking, which comprises a winding part, a wire core 6 and an insulation layer 9 wrapped outside the wire core 6. The winding part comprises a connecting rope 3, and elastic support sheets 2 are fixed on the connecting rope 3 at equal intervals. The connecting rope 3 is spirally wound on the insulation layer 9. Adjacent two support sheets 2 in the axial direction of the insulation layer 9 are staggered and overlapped. The end of the support sheet 2 away from the connecting rope 3 is in contact with the insulation layer 9. The winding part is coated with an outer skin 1.

[0037] The ratio of the area of the support sheet 2 to the area of the overlapping part of the adjacent two support sheets 2 in the axial direction of the insulation layer 9 is 2.0-5.0:1.0.

[0038] Further, the length of the support sheet 2 in the direction perpendicular to the connecting rope 3 is 2.0-5.0 cm.

[0039] Further, the connecting rope 3 is a carbon fiber rope, a steel wire rope or a plastic soft rope.

[0040] Further, the adjacent two support sheets 2 on the connecting rope 3 are staggered and overlapped.

[0041] The outer skin 1, the wire core 6 and the insulation layer 9 used in the present application are all common components of cables in the prior art, and their materials and production processes are all known technologies, which will not be described here.

[0042] The working process and principle of the embodiment are as follows:

[0043] When the power cable is subjected to external forces such as bending, stretching, and twisting, the interleaved support pieces 2 in the winding member can slide relative to each other, and the stress at the bending position of the power cable is not concentrated on one point of the outer skin 1, but is dispersed through the sliding of the interleaved support pieces 2, thereby avoiding the cracking of the outer skin 1 due to excessive stretching.

[0044] When the power cable is subjected to an impact, the winding member absorbs and buffers part of the impact, reducing the risk of damage to the wire core 6 and the insulation layer 9.

[0045] The power cable is easy to bend, protecting the internal insulation layer 9 and wire core 6 from damage, and the interleaved support pieces 2 can prevent gnawing by rodents and other gnawing animals.

[0046] Embodiment Two:

[0047] As shown in Figure 1 The embodiment discloses a power cable for reducing the cracking of the outer skin, which has a structure substantially the same as that of the first embodiment, except that a receiving cavity 4 is formed between the outer skin 1 and the insulation layer 9, and the receiving cavity 4 is filled with a sealing liquid for repairing the cracking of the outer skin.

[0048] The working process and principle of the embodiment are as follows:

[0049] When the outer skin 1 cracks and a breakage appears, the sealing liquid in the receiving cavity 4 flows to the outer circumferential side of the outer skin 1 through the breakage of the outer skin 1, the sealing liquid solidifies to seal the breakage of the outer skin 1, thereby improving the service life of the power cable and reducing the maintenance cost.

[0050] Preferably, the outer skin 1 is made of cross-linked polyethylene, and the insulation layer 9 is made of cross-linked polyethylene or polyethylene.

[0051] Further, the injection of the sealing liquid into the receiving cavity 4 of the power cable includes the following steps:

[0052] The power cable is placed in a negative pressure container, one end of the power cable is provided with a one-way valve, the one-way valve allows the air in the receiving cavity 4 to flow outwardly through the one-way valve, the worker uses a vacuum pump to extract the air in the negative pressure container, when the gauge pressure in the negative pressure container is-0.093 MPa to-0.098 MPa, the worker uses a mechanical arm or a time delay release structure to stretch the end of the power cable away from the one-way valve into a container containing the sealing liquid, and then the negative pressure container returns to one atmosphere pressure, the end of the power cable away from the one-way valve remains in the sealing liquid for 1 h-24 h, and the receiving cavity 4 inhales the sealing liquid.

[0053] Further, the support pieces 2 are elastic metal sheets, a part of the support pieces 2 are grounded through a grounding wire to achieve electromagnetic shielding of the wire core 6, and preferably the support pieces 2 are made of aluminum alloy or galvanized steel.

[0054] Further, the plugging liquid is sodium silicate solution or borate ester fire-retardant liquid.

[0055] Further, polyhydric alcohol is added in the plugging liquid to reduce the minimum use temperature of the power cable, and the polyhydric alcohol is ethylene glycol, propylene glycol or glycerol.

[0056] Embodiment three:

[0057] As shown in Figure 1 and Figure 3 , the embodiment discloses a power cable with reduced cable sheath cracking, which has substantially the same structure as that of embodiment two, except that the support sheet 2 of the winding member of the embodiment is provided with an opening 5.

[0058] The working process and principle of the embodiment are as follows:

[0059] The opening 5 facilitates the flow of the plugging liquid inside and outside the support sheet 2.

[0060] Embodiment four:

[0061] As shown in Figure 1 and Figure 2 , the embodiment discloses a power cable with reduced cable sheath cracking, which has substantially the same structure as that of embodiment three, except that the embodiment further comprises a long bag body 7 spirally wound on the insulation layer 9, and the long bag body 7 is fixedly connected with the connecting rope 3, and the diameter of the connecting rope 3 is greater than the thickness of the support sheet 2, and the connecting rope 3 provides a containing space for the long bag body 7.

[0062] The long bag body 7 has a folded state and an expanded state, the folded state of the long bag body 7 has a first volume, and the expanded state of the long bag body 7 has a second volume, and the second volume is greater than the first volume.

[0063] The worker fills the long bag body 7 with gas, and the long bag body 7 changes from the folded state to the expanded state.

[0064] The working process and principle of the embodiment are as follows:

[0065] During the process of inhaling the plugging liquid in the accommodating cavity 4, the long bag body 7 is in the folded state.

[0066] When the containment cavity 4 is completely filled with the sealing liquid, and both ends of the power cable are sealed, one end of the long bag body 7 penetrates the sealing position and extends out of the outer skin 1, the worker injects gas into the long bag body 7, the long bag body 7 in the containment cavity 4 changes from the folded state to the inflated state, the hydraulic pressure of the sealing liquid in the containment cavity 4 rises, and after the breakage of the outer skin 1, the sealing liquid in the containment cavity 4 flows out of the breakage, and after multiple breakages of the outer skin 1, the sealing liquid can seal multiple breakages, thereby improving the safety of the power cable and reducing the risk of accidents.

[0067] Further, the gas is air, carbon dioxide, helium or nitrogen.

[0068] Embodiment five:

[0069] As shown in Figure 1 , the embodiment discloses a power cable for reducing cable outer skin cracking, which has substantially the same structure as that of embodiment one, except that the support sheet 2 of the embodiment is an elastic plastic sheet.

[0070] Further, a shielding layer for preventing electromagnetic interference is arranged between the winding member and the outer skin 1.

[0071] Embodiment six:

[0072] As shown in Figures 4-6 , the embodiment discloses a mounting device, which is used with the power cable for reducing cable outer skin cracking of any one of embodiments one to five, and includes a base 10, a rotating ring 8 mounted on the base 10, a plurality of blocking members 802 arranged at equal angles on the outer circumferential side of the ring 8, the base 10 and one end of an elastic clamping member 15 being fixedly connected, the other end of the elastic clamping member 15 being close to the outer circumferential side of the ring 8, a plurality of rotating wheels 806 being mounted at equal angles on the inner circumferential side of the ring 8, the angle between the axis of the rotating wheel 806 and the axis of the ring 8 being less than 90°, and the angle between the axis of the rotating wheel 806 and the axis of the ring 8 being greater than or equal to 45°.

[0073] The ring 8 includes a long arc segment 801, and a short arc segment 804 is mounted at the gap of the long arc segment 801 and can be opened and closed.

[0074] The elastic clamping member 15 and the blocking member 802 cooperate to enable the ring 8 to rotate only when the torque acting on the ring 8 exceeds a set value.

[0075] The working process and principle of the embodiment are as follows:

[0076] During the wiring process of the power cable for reducing cable outer skin cracking, the base 10 is located on a placement plane, the axis of the ring 8 is arranged horizontally, the power cable passes through the ring 8, and the outer skin 1 of the power cable is pressed on the rotating wheel 806.

[0077] During the process of the worker pulling the power cable, the elastic clip 15 abuts against the blocking member 802, thereby restricting the rotation of the ring 8. The rotating wheel 806 causes the power cable to swing horizontally, and the height of the power cable at the ring 8 increases. When the torque of the power cable on the ring 8 exceeds the set value, the elastic clip 15 and the blocking member 802 disengage, the power cable causes the ring 8 to rotate, the height of the power cable at the ring 8 decreases, and the elastic clip 15 abuts against another blocking member 802.

[0078] After the power cable is laid, the short arc segment 804 on the long arc segment 801 is opened, and the power cable is detached from the long arc segment 801.

[0079] During the installation of the power cable, the power cable swings horizontally to avoid stress concentration in the outer sheath 1.

[0080] Furthermore, the direction of the frictional force on the outer skin 1 changes continuously, reducing the relative sliding between the outer skin 1 and the insulating layer 9, thereby reducing the deformation of the outer skin 1.

[0081] Furthermore, the elastic clip 15 is an elastic metal sheet or an elastic plastic sheet.

[0082] Furthermore, an arc-shaped groove is provided on the base 10, and the ring 8 and the arc-shaped groove are slidably connected. The arc-shaped groove allows the ring 8 to rotate around the axis of the ring 8.

[0083] Furthermore, the blocking member 802 is a slot formed on the outer periphery of the ring 8 or a protrusion fixed on the outer periphery of the ring 8, and an elastic pad is installed on the rotating wheel 806.

[0084] Example 7:

[0085] like Figure 4 As shown, this embodiment discloses an installation device, whose structure is roughly the same as that of Embodiment Six. The difference is that in this embodiment, at least two support rods 11 are fixed on the base 10. The support rods 11 are in contact with the support surface, which improves the stability of the position of the base 10 during the power cable wiring process.

[0086] Example 8:

[0087] like Figure 5 As shown, this embodiment discloses an installation device, the structure of which is roughly the same as that of Embodiment Six. The difference is that in this embodiment, a hook 13 is fixed on the base 10, and a positioning bolt 12 is installed on the hook 13.

[0088] The working process and principle of this embodiment are as follows:

[0089] The worker attaches the hook 13 to the vertical side of the cable tray, and then rotates the bolt 12 so that the bolt 12 presses against the vertical side of the cable tray. This installation equipment is easy to install on the cable tray.

[0090] Example 9:

[0091] like Figures 4-6 As shown, this embodiment discloses an installation device, whose structure is roughly the same as that of Embodiment Six. The difference is that in this embodiment, both ends of the base 10 are fixed with a long strip of soft bearing membrane 14.

[0092] The carrier membrane 14 is located on the wiring path of the power cable to reduce the resistance to the movement of the power cable.

[0093] Preferably, the carrier membrane 14 is made of plant fiber fabric, synthetic fiber fabric, or blended fabric.

[0094] Example 10:

[0095] like Figures 4-6 As shown, this embodiment discloses an installation device, whose structure is roughly the same as that of Embodiment Six. The difference is that in this embodiment, one end of the long arc segment 801 and the short arc segment 804 are connected by a rotating connector 803, and the other end of the long arc segment 801 and the short arc segment 804 are detachably connected by a limiting member 805.

[0096] The working process and principle of this embodiment are as follows:

[0097] Rotating connector 803 allows the long arc segment 801 and the short arc segment 804 to rotate relative to each other.

[0098] Furthermore, the rotating connector 803 is a hinge, hinge seat, or adhesive tape, and the limiting component 805 is a Velcro, bolt, clip, or quick-release pin.

[0099] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A power cable with reduced outer sheath cracking, comprising a core (6), an insulation layer (9) surrounding the core (6), characterized in that: Also include winding piece, the winding piece includes connecting rope (3), the support piece (2) is fixed on the connecting rope (3) at equal intervals, the connecting rope (3) is spirally wound on the insulating layer (9), the axis direction of the insulating layer (9) adjacent two support pieces (2) are staggered, and the end of the support piece (2) away from the connecting rope (3) and the insulating layer (9) contact, the winding piece is coated with the outer skin (1); The outer skin (1) and the insulating layer (9) form a containing cavity (4), the containing cavity (4) is filled with a sealing liquid for repairing the outer skin cracking, and a plurality of support pieces (2) of the winding piece are provided with an opening (5); Also include long strip bag body (7) spirally wound on the insulating layer (9), the long strip bag body (7) and the connecting rope (3) are fixedly connected; Wherein, the area ratio of the support piece (2) and the overlapping part of the adjacent two support pieces (2) in the axis direction of the insulating layer (9) is 2.0-5.0:1.0; Wherein, the long strip bag body (7) has a folded state and an expanded state, the long strip bag body (7) has a first volume in the folded state, and the long strip bag body (7) has a second volume in the expanded state, and the second volume is greater than the first volume; Wherein, the long strip bag body (7) is filled with gas, and the long strip bag body (7) is changed from the folded state to the expanded state.

2. A power cable with reduced cable sheath cracking according to claim 1, characterized in that: The sealing liquid is sodium silicate solution or borate ester fire-retardant liquid.

3. A power cable with reduced cable sheath cracking according to claim 1, characterized in that: The length of the support piece (2) in the direction perpendicular to the connecting rope (3) is 2.0cm-5.0cm.

4. A power cable with reduced cable sheath cracking according to claim 1, characterized in that: The support piece (2) is an elastic metal sheet or an elastic plastic sheet, and the connecting rope (3) is a carbon fiber rope, a steel wire rope or a plastic soft rope.

5. An installation device for use in conjunction with a power cable according to any one of claims 1-4, c h a r a c t e r i s e d in that: It includes a base (10), the base (10) is installed with a rotating ring (8), the outer circumferential side of the ring (8) is provided with a plurality of blocking pieces (802) at equal angles, the base (10) and one end of the elastic clamping piece (15) are fixedly connected, the other end of the elastic clamping piece (15) is close to the outer circumferential side of the ring (8), and a plurality of rotating rotating wheels (806) are installed at equal angles on the inner circumferential side of the ring (8), the angle between the axis of the rotating wheel (806) and the axis of the ring (8) is less than 90°; The ring (8) includes a long circular arc segment (801), and a short circular arc segment (804) is installed at the notch of the long circular arc segment (801) and can be opened and closed; Wherein, the elastic clamping piece (15) and the blocking piece (802) cooperate to make the ring (8) rotate only when the torque acting on the ring (8) exceeds a set value.

6. The mounting apparatus of claim 5, wherein: The base (10) is fixed with not less than two support rods (11), or the base (10) is fixed with a clamping hook (13), and the clamping hook (13) is installed with a positioning bolt (12).

7. The mounting apparatus of claim 5, wherein: Both ends of the base (10) are fixed with a bearing film (14); One end of the long circular arc segment (801) and the short circular arc segment (804) are connected through a rotating connecting piece (803), and the other end of the long circular arc segment (801) and the short circular arc segment (804) are detachably connected through a limiting piece (805).

Images