A cable with threading and bending protection

Abstract

The invention relates to the technical field of cables, and discloses a threading bending protective cable, comprising a conductor, an inner insulating layer and an outer sheath, wherein the inner insulating layer is wrapped around the outer circumference of the conductor, and the outer sheath is wrapped around the outside of the inner insulating layer; the outer sheath comprises a sheath body layer and a tensile fiber layer, the tensile fiber layer is close to the outer circumference of the outer sheath, and the tensile fiber layer comprises a plurality of brittle tensile fiber filaments; the tensile fiber filaments are fixedly connected to the sheath body layer, and the plurality of tensile fiber filaments all extend along the length direction of the outer sheath and circumferentially surround the inside of the sheath body layer; the circumferential part of the sheath body layer between the tensile fiber layer and the inner circumference of the outer sheath is the first part, and the circumferential part of the sheath body layer between the tensile fiber layer and the outer circumference of the outer sheath is the second part, and the hardness of the first part is less than the hardness of the second part; the outer diameter of the protective cable is D, the set turning radius of the protective cable is R, the minimum bending radius of the tensile fiber filaments is r, 6D≤R≤25D, and r≤R.

Description

Technical Field

[0001] The invention relates to the technical field of power cables, in particular to a threading and bending protection type cable. Background Art

[0002] Cable threading and laying is an important part of power construction. Usually, the cables are pulled through cable trenches or cable ducts and reach the designated positions.

[0003] During the threading process, the cable bends at the corner. If the bending radius is too small, it is easy to cause cable damage, which may lead to power accidents in serious cases. The main reason is that the cable itself has a certain diameter. When the cable is bent during threading, an extrusion force is generated on the inside of the corner and a tensile force is generated on the outside of the corner. The force on the inside and outside is unbalanced, which can easily cause the core to break and the inner insulation layer to rupture.

[0004] Subsequently, a Chinese utility model patent with authorization announcement number CN205845549U and authorization announcement date 2016.12.28 disclosed a cable, including an outer sheath, a shielding layer arranged in the inner cavity of the outer sheath, and a power transmission wire arranged in the inner cavity of the shielding layer. The inner cavity of the shielding layer is also provided with tensile fibers, and reinforcing fibers are arranged between the shielding layer and the outer sheath. The tensile fibers are acrylic fibers, which are used to enhance the mechanical strength of the cable and make it difficult to be torn apart; the reinforcing fibers include an acrylic fiber inner core, which is wrapped with flat copper wire and has a certain expansion and contraction ability. At the same time, the flat structure will restrain each other when bending, which can significantly increase the bending radius and enhance the bending resistance.

[0005] Existing cables are equipped with reinforced fibers consisting of an acrylic fiber inner core and an outer wrapped flat copper wire. Although this can increase the bending radius, it also makes it difficult to turn the cable and cannot meet the requirements of flexible turning during threading construction. At the same time, it can prevent the problem of core breakage and rupture of the inner insulation layer due to a small bending radius. Summary of the invention

[0006] The technical problem to be solved by the present invention is that although the reinforced fiber of the existing cable increases the bending radius, it makes the cable difficult to turn and cannot meet the requirement of flexible turning during threading construction, while preventing the problem of core breakage and rupture of the inner insulation layer due to a small bending radius.

[0007] In order to solve the above technical problems, the present invention provides a technical solution for a threading bending protection type cable:

[0008] Threading bend protected cable includes:

[0009] A conductor, an inner insulating layer and an outer sheath, wherein the inner insulating layer is wrapped around the outer circumference of the conductor, and the outer sheath is wrapped around the outside of the inner insulating layer;

[0010] The outer sheath comprises a sheath body layer and a tensile fiber layer, wherein the tensile fiber layer is arranged close to the outer peripheral surface of the outer sheath, and the tensile fiber layer comprises a plurality of tensile fiber filaments, and the plurality of tensile fiber filaments are fixedly connected to the sheath body layer;

[0011] The tensile strength fiber is a brittle fiber, and a plurality of the tensile strength fiber are arranged along the length direction of the outer sheath, and a plurality of the tensile strength fiber are arranged circumferentially inside the sheath body layer;

[0012] The circumferential portion of the sheath body layer between the tensile fiber layer and the inner circumferential surface of the outer sheath is the first portion, and the circumferential portion of the sheath body layer between the tensile fiber layer and the outer circumferential surface of the outer sheath is the second portion, and the hardness of the first portion is less than the hardness of the second portion;

[0013] The outer diameter of the protective cable is D, the set turning radius of the protective cable is R, and the minimum bending radius of the tensile fiber is r, satisfying: 6D≤R≤25D, and r≤R.

[0014] Furthermore, the sheath body layer is an integrated structure, and the tensile-resistant fibers are cross-linked with the sheath body layer.

[0015] Furthermore, in the radial direction of the outer sheath, the thickness of the sheath body layer is H, and the diameter of the tensile-resistant fiber filament is d, satisfying: d≤0.02H.

[0016] Furthermore, in the radial direction of the outer sheath, the minimum distance between the tensile fiber layer and the outer peripheral surface of the outer sheath is h, satisfying: 0.1H≤h≤0.2H.

[0017] Furthermore, the tensile strength fiber yarn is glass fiber yarn or ceramic fiber yarn, and the diameter d of the tensile strength fiber yarn is any size between 10 μm and 100 μm.

[0018] Furthermore, the sheath body layer is a split double-layer structure, which includes a first sheath body layer and a second sheath body layer wrapped outside the first sheath body layer, and the tensile fiber layer is bonded and connected between the first sheath body layer and the second sheath body layer;

[0019] The first sheath body layer constitutes a first portion of the sheath body layer between the tensile fiber layer and the inner circumference of the outer sheath, and the second sheath body layer constitutes a second portion of the sheath body layer between the tensile fiber layer and the outer circumference of the outer sheath.

[0020] Further, in the radial direction of the outer sheath, the thickness of the first sheath main body layer is H1, and the thickness of the second sheath main body layer is H2, satisfying: H=H1+H2, 0.1H≤H2≤0.2H.

[0021] Furthermore, a difference in Rockwell hardness between the second sheath body layer and the first sheath body layer is greater than 20 HR.

[0022] Furthermore, at least two protrusions are provided on the tensile-resistant fiber yarn, and at least two of the protrusions are spaced apart in the length direction of the tensile-resistant fiber yarn, and the sheath body layer is engaged with the protrusions.

[0023] Furthermore, the outer surface of the tensile-resistant fiber is provided with a frosted portion, and the sheath body layer is solidly connected to the frosted portion.

[0024] Furthermore, the sheath body layer is made of at least one of polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, fluoroplastic, nylon plastic, chloroprene rubber, silicone rubber, and nitrile rubber.

[0025] Furthermore, the tensile strength fiber yarn is provided with a plurality of segments along the length direction of the outer sheath, and the tensile strength fiber yarns of adjacent segments are overlapped with each other in the circumferential direction of the outer sheath.

[0026] Furthermore, the unit segment length of the tensile-resistant fiber is L, satisfying: L≥0.5r.

[0027] Furthermore, in the circumferential direction of the outer sheath, the tensile strength fibers are evenly distributed at circumferential intervals, and the distribution density of the tensile strength fibers is ρ, satisfying: ρ≥2 pieces / mm.

[0028] Furthermore, a shielding layer is further provided on the inner circumferential surface of the outer sheath, and in the radial direction of the outer sheath, the shielding layer and the inner insulating layer are arranged at intervals, and a buffer body is filled in the interval between the shielding layer and the inner insulating layer;

[0029] Alternatively, the outer circumferential surface of the inner insulating layer is further covered with a shielding layer, and in the radial direction of the outer sheath, the shielding layer and the outer sheath are arranged at an interval, and the interval between the shielding layer and the outer sheath is filled with a buffer body.

[0030] Compared with the prior art, the threading and bending protective cable of the present invention has the following beneficial effects: the threading and bending protective cable adopts the design form of a conductor, an inner insulating layer, an outer sheath and a tensile fiber layer, wherein the inner insulating layer is wrapped around the outer peripheral surface of the conductor, the inner insulating layer plays an electrical insulating role for the conductor, and can prevent current leakage from causing safety hazards; the outer sheath is wrapped around the outside of the inner insulating layer, and the inner core of the cable is covered and protected by the outer sheath, reducing mechanical damage to the conductor and the inner insulating layer caused by external forces, and at the same time avoiding the intrusion of external moisture to corrode and damage the conductor.

[0031] Moreover, the outer sheath includes a sheath body layer and a tensile fiber layer, the tensile fiber layer is arranged close to the outer peripheral surface of the outer sheath, the tensile fiber layer includes a plurality of tensile fiber filaments, and the plurality of tensile fiber filaments are fixedly connected to the sheath body layer. The tensile fiber layer is used to form a reinforcement layer inside the sheath body layer, thereby improving the overall tensile strength of the outer sheath, ensuring that the outer sheath can withstand sufficient traction during the threading construction process, thereby ensuring the structural reliability of the entire protective cable.

[0032] The tensile fiber is a brittle fiber. A plurality of tensile fiber filaments are arranged along the length direction of the outer sheath, and a plurality of tensile fiber filaments are arranged circumferentially inside the sheath body layer. The tensile fiber layer is composed of a plurality of tensile fiber filaments. The tensile fiber filaments have both good tensile strength and brittle fracture characteristics. The circumferential portion of the sheath body layer between the tensile fiber layer and the inner circumferential surface of the outer sheath is the first portion, and the circumferential portion of the sheath body layer between the tensile fiber layer and the outer circumferential surface of the outer sheath is the second portion. There is a hardness difference between the first portion and the second portion.

[0033] On the one hand, the tensile fiber layer significantly improves the tensile performance of the outer sheath in its length direction. When the cable is bent and deformed, the tensile fiber filaments located outside the corner play a significant role in strengthening the outer sheath outside the corner, preventing the outer sheath outside the corner from being torn due to excessive tension. For the outer sheath outside the corner, the tensile fiber filaments exert a compressive force on the cable core toward the center of the corner, effectively balancing the internal stress of the cable core itself, thereby reducing the risk of bending and fracture of the conductor and the inner insulation layer.

[0034] On the other hand, when the cable is bent and deformed, the outer sheath located at the inner part of the corner is subjected to the combined effects of bending and extrusion, and the tensile fiber filaments located at the inner part of the corner do not produce a significant reaction force on this part of the outer sheath, ensuring that the outer sheath located at the inner part of the corner can be smoothly bent and extruded. In particular, even if the turning radius R' of the outer sheath located at the inner part of the corner is small, the tensile fiber filaments are subjected to unbalanced internal and external extrusion stresses between the first part and the second part of the sheath body layer. The smaller the turning radius, the more unbalanced the internal and external extrusion stresses, so that the tensile fiber filaments can be brittlely broken inside the sheath body layer, avoiding the difficulty of turning the cable and ensuring the flexibility of the sheath body layer as the entire cable bends and deforms.

[0035] In summary, the sheath body layer of the threading and bending protection cable is designed with a tensile fiber layer, and is combined with brittle tensile fiber filaments, a first part and a second part with a hardness difference, etc., so as to meet the requirements of flexible turning during threading construction, while preventing the problem of core breakage and rupture of the inner insulation layer due to too small a bending radius.

[0036] In addition, in the radial direction of the outer sheath, the minimum distance between the tensile fiber layer and the outer peripheral surface of the outer sheath is h, which satisfies: 0.1H≤h≤0.2H. The tensile fiber layer is designed to be sufficiently close to the outer peripheral surface of the outer sheath, which plays a key role in strengthening the surface part of the outer sheath close to the outer peripheral surface, which not only increases the bending radius of the tensile fiber filaments located outside the corner, but also reduces the bending radius of the tensile fiber filaments located inside the corner, while improving the tensile tearing performance of the outer sheath outside the corner and ensuring the bending flexibility of the outer sheath inside the corner. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 1 is a three-dimensional schematic diagram of a threading bending protection type cable according to an embodiment of the present invention;

[0038] Figure 2 is a schematic cross-sectional view of a threading bending protection type cable in an embodiment of the present invention;

[0039] Figure 3 yes Figure 2 A partial enlarged view of the central threading bending protection type cable;

[0040] Figure 4 is a planar cross-sectional view of a threading bending protection type cable at a corner in an embodiment of the present invention;

[0041] Figure 5 Schematic diagram of the force on the threading bending protection type cable at the corner in the embodiment of the present invention;

[0042] Figure 6It is a partial enlarged view of the tensile strength fiber of the threading bending protection type cable in an embodiment of the present invention;

[0043] Figure 7 It is a partial enlarged view of the tensile fiber of a threading bending protection type cable according to another embodiment of the present invention;

[0044] Figure 8 is a cross-sectional schematic diagram of a second threading and bending protection type cable according to another embodiment of the present invention;

[0045] Fig. 9 is a partial cross-sectional view of a third threading and bending protection type cable according to another embodiment of the present invention;

[0046] In the figure: 1-conductor, 2-inner insulating layer, 3-outer sheath, 30-sheath body layer, 301-first part, 302-second part, 303-first sheath body layer, 304-second sheath body layer, 31-tensile fiber layer, 310-tensile fiber filament, 311-protrusion, 312-frosted part, 32-shielding layer, 4-buffer, f-internal stress, F-compression force. DETAILED DESCRIPTION

[0047] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] like Figures 1 to 4 As shown, a threading bending protection type cable according to an embodiment of the present invention comprises a conductor 1, an inner insulating layer 2 and an outer sheath 3, wherein the inner insulating layer 2 is wrapped around the outer peripheral surface of the conductor 1, and the outer sheath 3 is wrapped around the outside of the inner insulating layer 2; the outer sheath 3 comprises a sheath body layer 30 and a tensile fiber layer 31, wherein the tensile fiber layer 31 is arranged close to the outer peripheral surface of the outer sheath 3, and the tensile fiber layer 31 comprises a plurality of tensile fiber filaments 310, and the plurality of tensile fiber filaments 310 are fixedly connected to the sheath body layer 30. The tensile fiber filaments 310 are brittle fibers, and the plurality of tensile fiber filaments 310 are all extended along the length direction of the outer sheath 3, and the plurality of tensile fiber filaments 310 are circumferentially arranged inside the sheath body layer 30.

[0052] The circumferential portion of the sheath body layer 30 between the tensile fiber layer 31 and the inner circumferential surface of the outer sheath 3 is the first portion 301, and the circumferential portion of the sheath body layer 30 between the tensile fiber layer 31 and the outer circumferential surface of the outer sheath 3 is the second portion 302. The hardness of the first portion 301 is less than the hardness of the second portion 302. The outer diameter of the protective cable is D, the set turning radius of the protective cable is R, and the minimum bending radius of the tensile fiber filament 310 is r, satisfying: 6D≤R≤25D, and r≤R.

[0053] The threading and bending protective cable adopts the design form of a conductor 1, an inner insulating layer 2, an outer sheath 3 and a tensile fiber layer 31, wherein the inner insulating layer 2 is wrapped around the outer peripheral surface of the conductor 1, and the inner insulating layer 2 plays an electrical insulating role for the conductor 1, which can prevent current leakage from causing safety hazards. The outer sheath 3 is wrapped around the outside of the inner insulating layer 2, and the inner core of the cable is covered and protected by the outer sheath 3, reducing the mechanical damage to the conductor 1 and the inner insulating layer 2 caused by external forces, and at the same time avoiding the corrosion and damage of the conductor 1 by the intrusion of external moisture.

[0054] Moreover, the outer sheath 3 includes a sheath body layer 30 and a tensile fiber layer 31, the tensile fiber layer 31 is arranged close to the outer peripheral surface of the outer sheath 3, and the tensile fiber layer 31 includes a plurality of tensile fiber filaments 310, and the plurality of tensile fiber filaments 310 are fixedly connected to the sheath body layer 30. The tensile fiber layer 31 is used to form a reinforcement layer inside the sheath body layer 30, thereby improving the overall tensile strength of the outer sheath 3, ensuring that the outer sheath 3 can withstand sufficient traction during the threading construction process, thereby ensuring the structural reliability of the entire protective cable.

[0055] The tensile fiber filaments 310 are brittle fibers, and a plurality of tensile fiber filaments 310 are all extended along the length direction of the outer sheath 3, and a plurality of tensile fiber filaments 310 are circumferentially arranged inside the sheath body layer 30. The tensile fiber layer 31 is composed of a plurality of tensile fiber filaments 310, and the tensile fiber filaments 310 have both good tensile strength and brittle fracture characteristics. The circumferential portion of the sheath body layer 30 between the tensile fiber layer 31 and the inner circumferential surface of the outer sheath 3 is the first portion 301, and the circumferential portion of the sheath body layer 30 between the tensile fiber layer 31 and the outer circumferential surface of the outer sheath 3 is the second portion 302, and there is a hardness difference between the first portion 301 and the second portion 302.

[0056] On the one hand, the tensile fiber layer 31 significantly improves the tensile performance of the outer sheath 3 in its length direction. When the cable is bent and deformed, the tensile fiber filaments 310 located outside the corner play a significant role in strengthening the outer sheath 3 outside the corner, preventing the outer sheath 3 outside the corner from being torn due to excessive tension. Figure 5 As shown, the tensile fiber filament 310 exerts a compressive force F on the cable inner core toward the center of the corner circle, effectively balancing the internal stress f of the cable inner core itself, thereby reducing the risk of bending and fracture of the conductor 1 and the inner insulating layer 2.

[0057] On the other hand, when the cable is bent and deformed, the outer sheath 3 located at the inner part of the corner is subjected to the combined effects of bending and extrusion, and the tensile fiber filaments 310 located at the inner part of the corner do not produce a significant reaction force on this part of the outer sheath 3, ensuring that the outer sheath 3 located at the inner part of the corner can be smoothly bent and extruded. In particular, even if the turning radius R' of the outer sheath 3 located at the inner part of the corner is small, the tensile fiber filaments 310 are subjected to unbalanced internal and external extrusion stresses between the first part 301 and the second part 302 of the sheath body layer 31. The smaller the turning radius, the more unbalanced the internal and external extrusion stresses, so that the tensile fiber filaments 310 can be brittlely broken inside the sheath body layer 30, avoiding the difficulty of turning the cable and ensuring the flexibility of the sheath body layer 30 as the entire cable is bent and deformed.

[0058] In addition, the outer diameter of the protective cable is D, the set turning radius of the protective cable is R, and the minimum bending radius of the tensile fiber filament 310 is r, which satisfies: 6D≤R≤25D, and r≤R. It should be noted that the set turning radius R of the protective cable refers to the arc radius corresponding to the arc length of the cable located outside the corner. The set turning radius R of the protective cable is between 6D and 25D, which can prevent the cable turning radius from being too small and causing damage to the inner core of the cable. The minimum bending radius r of the tensile fiber filament 310 is smaller than the set turning radius R of the protective cable. When the bending deformation of the cable reaches the set turning radius R, it is ensured that the tensile fiber filament 310 located outside the corner will not be brittlely broken, ensuring that the tensile fiber filament 310 here can continuously and stably produce the effect of strengthening the tensile resistance of the outer sheath 3.

[0059] In summary, the sheath body layer 30 of the threading and bending protective cable is designed with a tensile fiber layer 31, and is combined with the tensile fiber filaments 310 of brittle fibers, the first part 301 and the second part 302 with a hardness difference, etc., so as to meet the requirements of flexible turning during threading construction, and prevent the problem of core breakage and rupture of the inner insulation layer due to a small turning radius.

[0060] In this embodiment, the sheath body layer 30 is an integrated structure, and the tensile fiber filaments 310 are cross-linked with the sheath body layer 30. Specifically, the sheath body layer 30 is made of at least one of polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, fluoroplastic, nylon plastic, chloroprene rubber, silicone rubber, and nitrile rubber. For example: the sheath body layer 30 is made of polyvinyl chloride plastic, and the tensile fiber filaments 310 and the polyvinyl chloride plastic can be cross-linked and consolidated together by a melt molding process; or, the sheath body layer 30 is made of chloroprene rubber, and the tensile fiber filaments 310 and the chloroprene rubber can be cross-linked and consolidated together by a vulcanization process. The sheath body layer 30 and the tensile fiber filaments 310 of the integrated structure are cross-linked to improve the consolidation strength between the two, thereby ensuring that the outer sheath 3 can withstand greater tension and will not easily fall off. Accordingly, a hardening coating may be applied to the outer peripheral surface of the outer sheath 3, or the composition of the outer sheath 3 surface layer may be changed, or the outer sheath 3 surface layer may be subjected to heat hardening treatment, so that the sheath body layer 30 forms a first part 301 and a second part 302 with a hardness difference.

[0061] As a further preferred solution, in the radial direction of the outer sheath 3, the thickness of the sheath body layer 30 is H, and the diameter of the tensile fiber filament 310 is d, which satisfies: d≤0.02H. Figure 2As shown, the diameter d of the tensile fiber filament 310 occupies only a very small area inside the sheath body layer 30, thereby ensuring the structural integrity of the sheath body layer 30. For example, if the diameter d of the tensile fiber filament 310 is 0.05H, although the diameter of the tensile fiber filament 310 is increased, the tensile fiber filament 310 occupies a large area on the cross section of the sheath body layer 30, which easily leads to a reduction in the integrity of the sheath body layer 30.

[0062] Moreover, in the radial direction of the outer sheath 3, the minimum distance between the tensile fiber layer 31 and the outer peripheral surface of the outer sheath 3 is h, which satisfies: 0.1H≤h≤0.2H. The tensile fiber layer 31 is designed to be sufficiently close to the outer peripheral surface of the outer sheath 3, which plays a key role in strengthening the surface part of the outer sheath 3 close to the outer peripheral surface. It not only increases the bending radius of the tensile fiber filament 310 located on the outside of the corner, but also reduces the bending radius of the tensile fiber filament 310 located on the inside of the corner, while improving the tensile tearing performance of the outer sheath 3 on the outside of the corner, and ensuring the bending flexibility of the outer sheath 3 on the inside of the corner.

[0063] In this embodiment, the tensile fiber filaments 310 are glass fiber filaments or ceramic fiber filaments, and the diameter d of the tensile fiber filaments 310 is any size between 10 μm and 100 μm. Glass fiber filaments or ceramic fiber filaments have high tensile strength, easy brittle fracture, and good insulation performance, thereby achieving the purpose of tensile tear resistance, flexible bending, and reliable insulation of the outer sheath 3.

[0064] Moreover, at least two protrusions 311 are provided on the tensile-resistant fiber filament 310. Figure 6 As shown, at least two protrusions are arranged at intervals in the length direction of the tensile fiber filament 310, and the sheath body layer 30 is engaged with the protrusions 311. By providing at least two protrusions 311 on the tensile fiber filament 310, the consolidation strength between the tensile fiber filament 310 and the sheath body layer 30 can be increased, thereby ensuring the overall tensile performance of the outer sheath 3. Figure 7 As shown, in another embodiment of the threading bending protective cable of the present invention, the outer surface of the tensile-resistant fiber filament 310 is provided with a frosted portion 312, and the sheath body layer is solidly connected to the frosted portion 312. The frosted portion 312 can also effectively improve the solidification strength between the tensile-resistant fiber filament 310 and the sheath body layer.

[0065] It should be noted that the tensile fiber filaments 310 are provided with a plurality of segments along the length direction of the outer sheath 3, and the tensile fiber filaments 310 of adjacent segments are arranged to overlap each other in the circumferential direction of the outer sheath 3. As a further preferred embodiment, the unit segment length of the tensile fiber filaments 310 is L, satisfying: L ≥ 0.5r. The tensile fiber filaments 310 are arranged into a plurality of segments in the length direction of the outer sheath 3, and the tensile fiber filaments 310 of the circumferentially adjacent segments have overlapping parts, which can reduce the difficulty of forming the tensile fiber layer 31 inside the sheath body layer 30. The unit segment length L ≥ 0.5r of the tensile fiber filaments 310 can ensure that the tensile fiber filaments 310 play an effective tensile strengthening role, so that the inside of the sheath body layer 30 can be brittle fractured, thereby ensuring the bending flexibility of the outer sheath 3 at the inner part of the corner.

[0066] In addition, in the circumferential direction of the outer sheath 3, the tensile fiber filaments 310 are evenly distributed in the circumferential direction, and the distribution density of the tensile fiber filaments 310 is ρ, which satisfies: ρ≥2 pieces / mm. The distribution density of the tensile fiber filaments 310 in the circumferential direction of the outer sheath 3 is ρ≥2 pieces / mm, which further improves the overall tensile strength of the outer sheath 3. Moreover, a shielding layer 32 is also provided on the inner circumferential surface of the outer sheath 3. In the radial direction of the outer sheath 3, the shielding layer 32 and the inner insulating layer 2 are arranged at intervals, and the interval between the shielding layer 32 and the inner insulating layer 2 is filled with a buffer body 4. The buffer body 4 mainly plays the role of buffering force, isolating water vapor and enhancing electrical insulation, thereby improving the comprehensive performance of the protective cable. In order to meet different usage requirements, such as Figure 8 As shown, in another embodiment 2 of the threading bending protective cable of the present invention, the outer peripheral surface of the inner insulating layer 2 is also covered with a shielding layer 32, and in the radial direction of the outer sheath 3, the shielding layer 32 and the outer sheath 3 are arranged at an interval, and the interval between the shielding layer 32 and the outer sheath 3 is filled with a buffer body 4.

[0067] like Fig. 9 As shown, in the other embodiment 3 of the threading bending protective cable of the present invention, in order to meet different usage requirements, the sheath body layer 30 is a split double-layer structure, which includes a first sheath body layer 303, and a second sheath body layer 304 wrapped outside the first sheath body layer 303, and the tensile fiber layer 31 is bonded and connected between the first sheath body layer 303 and the second sheath body layer 304; the first sheath body layer 303 constitutes the first part of the sheath body layer 30 between the tensile fiber layer 31 and the inner peripheral surface of the outer sheath 3, and the second sheath body layer 304 constitutes the second part of the sheath body layer 30 between the tensile fiber layer 31 and the outer peripheral surface of the outer sheath 3. The tensile fiber layer 31 is bonded and connected between the first sheath body layer 303 and the second sheath body layer 304, which is less difficult to process than the cross-linking curing method, and can also ensure the tensile strength and integrity of the outer sheath 3.

[0068] As a further preferred solution, in the radial direction of the outer sheath 3, the thickness of the first sheath body layer 303 is H1, and the thickness of the second sheath body layer 304 is H2, satisfying: H=H1+H2, 0.1H≤H2≤0.2H. It should be noted that, since the thickness of the tensile fiber layer 31 is much smaller than the thickness H of the sheath body layer 30, the sum of the thickness H1 of the first sheath body layer 303 and the thickness H2 of the second sheath body layer 304 can be regarded as the thickness H of the sheath body layer 30. The Rockwell hardness difference between the second sheath body layer 304 and the first sheath body layer 303 is greater than 20HR. Under this Rockwell hardness difference, the internal and external extrusion stresses generated by the second sheath body layer 304 and the first sheath body layer 303 are significantly unbalanced, which can cause the tensile fiber filaments 310 to break brittlely inside the sheath body layer 30, thereby ensuring the flexibility of the cable in turning.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A threading bending protection cable, characterized in that it includes: A conductor (1), an inner insulating layer (2) and an outer sheath (3), wherein the inner insulating layer (2) is wrapped around the outer circumferential surface of the conductor (1), and the outer sheath (3) is wrapped around the outside of the inner insulating layer (2); The outer sheath (3) comprises a sheath body layer (30) and a tensile fiber layer (31), the tensile fiber layer (31) being arranged close to the outer peripheral surface of the outer sheath (3), the tensile fiber layer (31) comprising a plurality of tensile fiber filaments (310), and the plurality of tensile fiber filaments (310) being fixedly connected to the sheath body layer (30); The tensile strength fiber filaments (310) are brittle fibers, a plurality of the tensile strength fiber filaments (310) are arranged extending along the length direction of the outer sheath (3), and a plurality of the tensile strength fiber filaments (310) are arranged circumferentially inside the sheath body layer (30); The circumferential portion of the sheath body layer (30) between the tensile fiber layer (31) and the inner circumferential surface of the outer sheath (3) is a first portion (301), and the circumferential portion of the sheath body layer (30) between the tensile fiber layer (31) and the outer circumferential surface of the outer sheath (3) is a second portion (302), and the hardness of the first portion (301) is smaller than the hardness of the second portion (302); The outer diameter of the protective cable is D, the set turning radius of the protective cable is R, and the minimum bending radius of the tensile-resistant fiber (310) is r, satisfying: 6D≤R≤25D, and r≤R.

2. The threading bending protection type cable according to claim 1 is characterized in that: The sheath body layer (30) is an integrated structure, and the tensile-resistant fiber filaments (310) and the sheath body layer (30) are cross-linked and formed.

3. The threading bending protection type cable according to claim 1, characterized in that In the radial direction of the outer sheath (3), the thickness of the sheath body layer (30) is H, and the diameter of the tensile-resistant fiber filament (310) is d, satisfying: d≤0.02H.

4. The threading bending protection type cable according to claim 3 is characterized in that In the radial direction of the outer sheath (3), the minimum distance between the tensile fiber layer (31) and the outer peripheral surface of the outer sheath (3) is h, satisfying: 0.1H≤h≤0.2H.

5. The threading bending protection type cable according to claim 1, characterized in that: The tensile-resistant fiber filaments (310) are glass fiber filaments or ceramic fiber filaments, and the diameter d of the tensile-resistant fiber filaments (310) is any size between 10 μm and 100 μm.

6. The threading bending protection type cable according to claim 1, characterized in that: The sheath body layer (30) is a split double-layer structure, comprising a first sheath body layer (303) and a second sheath body layer (304) wrapped outside the first sheath body layer (303), and the tensile fiber layer (31) is bonded and connected between the first sheath body layer (303) and the second sheath body layer (304); The first sheath body layer (303) constitutes a first portion (301) of the sheath body layer (30) between the tensile-resistant fiber layer (31) and the inner circumferential surface of the outer sheath (3), and the second sheath body layer (304) constitutes a second portion (302) of the sheath body layer (30) between the tensile-resistant fiber layer (31) and the outer circumferential surface of the outer sheath (3).

7. The threading bending protection type cable according to claim 6, characterized in that In the radial direction of the outer sheath (3), the thickness of the first sheath main body layer (303) is H1, and the thickness of the second sheath main body layer (304) is H2, satisfying: H=H1+H2, 0.1H≤H2≤0.2H.

8. The threading and bending protection type cable according to claim 6, characterized in that: The difference in Rockwell hardness between the second sheath body layer (304) and the first sheath body layer (303) is greater than 20 HR.

9. The threading bending protection type cable according to claim 1, characterized in that At least two protrusions (311) are provided on the tensile-resistant fiber yarn (310), and the at least two protrusions (311) are arranged at intervals in the length direction of the tensile-resistant fiber yarn (310), and the sheath body layer (30) is engaged with the protrusions (311).

10. The threading bending protection type cable according to claim 1, characterized in that: The outer surface of the tensile-resistant fiber filament (310) is provided with a frosted portion (312), and the sheath body layer (30) is solidly connected to the frosted portion (312).

11. The threading bending protection type cable according to claim 1, characterized in that: The sheath body layer (30) is made of at least one of polyvinyl chloride plastic, polyethylene plastic, polypropylene plastic, fluoroplastic, nylon plastic, chloroprene rubber, silicone rubber, and nitrile rubber.

12. The threading bending protection type cable according to claim 1, characterized in that: The tensile-resistant fiber yarn (310) is provided with a plurality of segments along the length direction of the outer sheath (3); in the circumferential direction of the outer sheath (3), the tensile-resistant fiber yarns (310) of adjacent segments are arranged to overlap each other.

13. The threading bending protection type cable according to claim 12, characterized in that: The unit segment length of the tensile-resistant fiber yarn (310) is L, satisfying: L≥0.5r.

14. The threading bending protection type cable according to claim 1, characterized in that In the circumferential direction of the outer sheath (3), the tensile strength fiber yarns (310) are evenly distributed at circumferential intervals, and the distribution density of the tensile strength fiber yarns (310) is ρ, satisfying the following: ρ≥2 pieces / mm.

15. The threading bending protection type cable according to claim 1, characterized in that: The inner circumferential surface of the outer sheath (3) is further provided with a shielding layer (32); in the radial direction of the outer sheath (3), the shielding layer (32) and the inner insulating layer (2) are arranged at intervals, and the interval between the shielding layer (32) and the inner insulating layer (2) is filled with a buffer body (4); Alternatively, the outer peripheral surface of the inner insulating layer (2) is further provided with a shielding layer (32); in the radial direction of the outer sheath (3), the shielding layer (32) and the outer sheath (3) are arranged at intervals, and the interval between the shielding layer (32) and the outer sheath (3) is filled with a buffer body (4).

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