Light armored power cable and buffer layer extrusion die

Abstract

The utility model discloses a light armored power cable, comprising a cabling wire core and a buffer layer, the buffer layer comprises an inner layer, an outer layer and a supporting strip, the inner layer is sleeved outside the cabling wire core, the outer layer is sleeved outside the inner layer with a gap, the supporting strip is arranged in the gap between the inner layer and the outer layer along the axial direction of the cable, and the supporting strip is arranged in the gap between the inner layer and the outer layer. The inner edge and the outer edge are respectively connected with the inner layer and the outer layer in a propping manner, so that a cavity is formed between the inner layer and the outer layer, and the section of the cavity is of an arc-shaped strip structure. The light armored power cable is simple in structure and reasonable in arrangement, not only meets flexibility and bending performance required by the cable, but also has certain anti-pressure capability. The utility model further provides a buffer layer extrusion die.

Description

Technical Field

[0001] The utility model specifically relates to a light armored power cable and a buffer layer extrusion die. Background Art

[0002] There are many application environments for power cable laying, such as underground laying, bridge laying, pipe laying, etc. In some special environments, the cable needs to have a certain compressive capacity and good flexibility at the same time. For example, for general underground laid cables, due to reasons such as laying positions, the cables need to be metal armored to withstand a certain amount of pressure. However, the metal armor will affect the flexibility of the cable to a certain extent, resulting in poor bending performance in the laying environment. Content of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a light armored power cable aiming at the above deficiencies existing in the prior art. The cable has a simple structure and reasonable settings, which not only meets the flexibility and bending performance required by the cable, but also has a certain compressive capacity. The utility model also provides a buffer layer extrusion die.

[0004] The utility model provides a light armored power cable, which includes a stranded core and a buffer layer. The buffer layer includes an inner layer, an outer layer and support bars. The inner layer is sleeved outside the stranded core. The outer layer is sleeved outside the inner layer with a gap. The support bars are arranged axially along the cable between the gaps of the inner layer and the outer layer, and the inner and outer edges respectively support and connect the inner layer and the outer layer, so as to form a cavity between the inner layer and the outer layer. The cross-section of the cavity is in an arc-shaped strip structure.

[0005] Further, 6-10 support bars are arranged around the circumference of the cable. The cross-section width of the support bar is 5-10 mm, and the height is 5-10 mm.

[0006] Further, the inner layer, the outer layer and the support bars of the buffer layer are an integral structure jointly extruded outside the stranded core by an extrusion method.

[0007] Further, the stranded core includes an insulated core and a tape layer. The tape layer is a flexible material layer with elasticity, and is arranged outside the insulated core by a wrapping method.

[0008] Further, the wrapping overlap rate of the tape layer is 10%-50%.

[0009] Further, the stranded core further includes a filling layer, and the filling layer is filled between the insulated core and the tape layer.

[0010] Further, the insulated conductor core includes a conductive wire core and an insulating layer coated on the outside of the conductive wire core. There are multiple insulated conductor cores, and the insulated conductor cores are stranded into a bundle. The filling layer is filled in the gaps between the insulated conductor cores and the gaps between the insulated conductor cores and the tape layer to support the tape layer and ensure the roundness of the cable.

[0011] Further, the light armored power cable further includes a sheath layer, and the sheath layer is coated on the outside of the buffer layer.

[0012] The present invention also provides a buffer layer extrusion die for extruding the buffer layer of the above-mentioned light armored power cable. The buffer layer extrusion die includes a die core, a middle die and a die sleeve. The die core, the middle die and the die sleeve are all in a cylindrical structure. The central hole of the die core allows the stranded conductor core to penetrate. The middle die is provided with notches evenly distributed around the axis. The die core, the middle die and the die sleeve are coaxially sleeved with gaps in sequence from the inside to the outside, and each gap communicates with the extrusion material inlet of the buffer layer. The ports of each gap are used as extrusion material outlets. The stranded conductor core moves in a set direction during the extrusion process to form an inner layer outside the stranded conductor core penetrating the die core through the gap between the die core and the middle die; form support strips through the notches on the middle die; form an outer layer through the gap between the middle die and the die sleeve.

[0013] Further, the gaps between the die core and the middle die and between the middle die and the die sleeve are both tapered gaps that gradually converge in the set direction, and the notches on the middle die are slope-shaped notches that gradually approach the die core in the set direction.

[0014] The light armored power cable of the present invention includes a stranded conductor core and a buffer layer. The inner and outer edges of the support strips in the buffer layer respectively support and connect the inner layer and the outer layer of the buffer layer, so as to form a cavity with an arc-shaped strip structure between the inner layer and the outer layer. When the outside of the cable is squeezed, the outer layer first bears the pressure and deforms, and this cavity structure can provide a certain buffer space for the squeezed outer layer, avoiding the direct transmission of pressure to the internal stranded conductor core, offsetting the external stress to a certain extent, and protecting the integrity of the cable insulation. Moreover, this cavity structure is not only lighter than the previous metal armor, but also does not affect the flexibility of the cable itself, making the cable of the present invention have good bending performance. And the cavity is an arc-shaped strip structure supported by the support strips between the inner and outer layers. This arc-shaped strip structure occupies a large proportion of the space between the inner and outer layers, improving the ability to offset external stress, and at the same time making the cavity thickness distribution between the inner and outer layers very uniform, making the stress resistance ability of the cable in the circumferential direction more evenly stable. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the light armored power cable in Embodiment 1 of the present invention;

[0016] Figure 2It is a schematic axial cross-sectional view of the buffer layer extrusion die in Embodiment 2 of the present utility model;

[0017] Figure 3 It is a schematic radial cross-sectional view of the buffer layer extrusion die in Embodiment 2 of the present utility model.

[0018] In the figure: 1, cable core; 11, insulating core; 111, conductive core; 112, insulating layer; 12, tape layer; 13, filling layer; 2, buffer layer; 21, inner layer; 22, outer layer; 23, support bar; 3, sheath layer; 4, die core; 5, middle die; 51, notch; 6, die sleeve. Detailed implementation manners

[0019] Next, the technical solutions in the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present utility model.

[0020] In the description of the present utility model, it should be noted that the terms "upper", "lower", etc. indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience and simplification of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0021] In the description of the present utility model, the terms "first", "second", "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "connection", "setting", "installation", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0023] Embodiment 1

[0024] Such as Figure 1As shown, the light armored power cable of this embodiment includes a cable core 1 and a buffer layer 2, the buffer layer 2 includes an inner layer 21, an outer layer 22 and a support bar 23, the inner layer 21 is sleeved on the outside of the cable core 1, the outer layer 22 is sleeved on the outside of the inner layer 21 with a gap, the support bar 23 is arranged between the gap between the inner layer 21 and the outer layer 22 along the cable axis, and the inner and outer edges respectively support and connect the inner layer 21 and the outer layer 22, so that a cavity is formed between the inner layer 21 and the outer layer 22, and the cross section of the cavity is an arc-shaped strip structure. That is, the gap between the inner layer 21 and the outer layer 22 is supported by the support of the support bar 23 and is divided into multiple sections of cavities with arc-shaped cross sections. When the outside of the cable is squeezed, the outer layer 22 first bears the pressure and deforms, and this cavity structure can provide a certain buffer space for the compressed outer layer 22, avoiding the direct transmission of pressure to the internal cable core 1, offsetting the external stress to a certain extent, and protecting the integrity of the cable insulation. Moreover, this cavity structure is not only lighter than the previous metal armor, but also does not affect the flexibility of the cable itself, so that the cable has good bending performance. The cavity is an arc-shaped strip structure supported by the support bar 23 between the inner and outer layers. This arc-shaped strip structure occupies a large space between the inner and outer layers, which improves the ability to offset external stress. At the same time, it also makes the cavity thickness distribution between the inner and outer layers very uniform, making the stress resistance of the cable in the circumferential direction more even and stable.

[0025] In this embodiment, 6 to 10 support bars 23 are arranged around the circumference of the cable, and the cross-sectional width (i.e., the dimension perpendicular to the radial direction of the cable) of the support bar 23 is 5 to 10 mm, and the height (i.e., the dimension along the radial direction of the cable) is 5 to 10 mm. This distribution makes the central angle of each cavity corresponding to the radial cross-section of the cable an acute angle, that is, the arc distribution area of the cavity will not be too large, and the number is just right, so as to avoid the situation where the inner layer 21 and the outer layer 22 of the buffer layer 2 are squeezed together due to too few cavities when the cable is subjected to external stress. The cross-section of the support bar 23 is rectangular, and the width and height are both within the range of 5 to 10 mm. This structure can ensure that the support bar 23 will not be squeezed and deformed when the cable is subjected to external stress.

[0026] In this embodiment, in any cross section of the buffer layer 2, the inner layer 21 and the outer layer 22 are distributed in concentric circles, that is, there is a gap with a consistent spacing between the two. The cross section of the support bar 23 is rectangular, and a plurality of support bars 23 are provided, which are evenly distributed in the gap between the inner layer 21 and the outer layer 22 to divide the gap into an arc-shaped strip structure with uniform width.

[0027] This regular cross-sectional structure makes the buffer layer 2 easier to prepare, and is particularly suitable for extrusion. In this embodiment, the inner layer 21, the outer layer 22 and the support strips 23 of the buffer layer 2 are an integral structure extruded together on the outside of the cable core 1 by extrusion.

[0028] In this embodiment, the cabled core 1 includes an insulated core 11 and a tape layer 12. The tape layer 12 is a flexible material layer with elasticity and is arranged outside the insulated core 11 by the wrapping method. By setting the elastic tape layer 12, the insulated core 11 can be effectively protected from being damaged by external mechanical forces, and a solution for resisting external stresses can be further provided for the internal insulated core 11. Acting together with the cavity of the external buffer layer 2, it ensures that the cable insulated core 11 is not affected by external stresses. The thickness of the tape layer 12 is 0.5 mm to 10 mm.

[0029] In this embodiment, the tape layer 12 is wrapped in an overlapping wrapping method (a conventional wrapping method, which will not be specifically described here), and the wrapping overlap rate is 10% - 50%.

[0030] In this embodiment, the tape layer 12 can be selected as a sponge buffer tape or a buffer tape with flame retardancy. It is evenly and overlappingly wrapped around the insulated core 11 by a wrapping head, and the overlap rate is selected as 15%. It can not only prevent the filling from falling, but also has a certain buffering property.

[0031] The buffer layer 2 is a plastic extrusion layer with a cavity in the middle and can be extruded from polyvinyl chloride material. Specifically, it can be extruded by an extrusion die with a special design as shown in Figure 2 After extrusion, a cavity will be formed. When the cable is subjected to external mechanical stresses, the cavity can play a certain buffering role.

[0032] In this embodiment, the cabled core 1 further includes a filling layer 13. The filling layer 13 is filled between the insulated core 11 and the tape layer 12. The filling layer 13 can be composed of ordinary polypropylene or a flame retardant filling rope, which can effectively ensure the roundness of the cable.

[0033] In this embodiment, the insulated core 11 includes a conductive core 111 and an insulating layer 112 coated on the outside of the conductive core 111. The conductive core 111 is stranded by multiple copper single wires, and the cross-sectional area is selected from 1 mm 2 to 500 mm 2 according to specific requirements such as the use of the cable, design and manufacturing regulations, etc. The insulating layer 112 is extruded from polyvinyl chloride or cross-linked polyethylene insulating cable material. There are multiple insulated cores 11, and each insulated core 11 is stranded into a bundle. According to different cross-sections, different numbers are selected to be stranded together. The number of insulated cores 11 can be 1 to 5 according to actual needs. The filling layer 13 is filled in the gaps between each insulated core 11 and the gap between the insulated core 11 and the tape layer 12 to support the tape layer 12, so that on the radial cross-section of the cable, the inner surface of the tape layer 12 is kept tangent to the outer surfaces of each internal insulated core 11 and the roundness of the cable is ensured.

[0034] In this embodiment, specifically, the insulated conductor cores 11 are formed by stranding four insulated conductor cores 11, and the stranding direction is right-handed. The conductor structure of the insulated conductor core 11 (i.e., the conducting wire core 111) meets the requirements of the 5th type of conductor structure in GB / T 3956, and its DC resistance complies with the provisions of GB / T 3956. The copper single wires in the conductor are drawn from high-quality oxygen-free copper rods, and the cross-section is 25 mm 2 . The insulating layer 112 is a cross-linked polyethylene insulating layer with a thickness of 0.7 mm to 3.0 mm, and in this embodiment, it is further preferably 0.9 mm. A flame-retardant or non-flame-retardant filling material is filled around the cable core as the filling layer 13 to ensure the roundness of the cable.

[0035] In this embodiment, the cable further includes a sheath layer 3, and the sheath layer 3 covers the outside of the buffer layer 2. The thickness of the sheath layer 3 is 1.8 mm to 5.0 mm, and the material can be selected from one of flame-retardant or non-flame-retardant polyvinyl chloride, polyethylene, and polyolefin. As the outer sheath of the cable, it can provide further protection to the cable while meeting special performance requirements such as flame retardancy, cold resistance, ultraviolet resistance, and anti-rat and anti-ant. The sheath layer 3 of this embodiment is extruded from polyvinyl chloride sheath material, and the thickness of the sheath layer is 1.8 mm, which is evenly extruded on the outer layer of the buffer layer 2 through an extruder.

[0036] This embodiment relates to the technical field of cables, specifically to a light armored power cable. The cable from the inside to the outside is successively the conducting wire core 111, the insulating layer 112 wrapped around the outside of the conducting wire core 111, the filling around the cable core (i.e., the filling layer 13), the buffer sponge tape (i.e., the tape layer 12), the extruded buffer layer 2, and the sheath layer 3. Through reasonable structural settings, the cable not only has good flexibility and bendability but also can offset external stress to a certain extent and protect the integrity of the cable insulation.

[0037] Embodiment 2

[0038] The buffer layer extrusion die of this embodiment is used to extrude the buffer layer 2 of the light armored power cable in Embodiment 1. The buffer layer extrusion die includes a die core 4, a middle die 5, and a die sleeve 6. The die core 4, the middle die 5, and the die sleeve 6 are all in a cylindrical structure. The central hole of the die core 4 allows the stranding core 1 to pass through. The middle die 5 is evenly distributed with notches 51 around the axis. The die core 4, the middle die 5, and the die sleeve 6 are coaxially sleeved with gaps from the inside to the outside in sequence, and each gap communicates with the extrusion material inlet of the buffer layer 2. The ports of each gap are used as extrusion material outlets. The stranding core 1 moves along a set direction during the extrusion process to form an inner layer 21 outside the stranding core 1 passing through the die core 4 through the gap between the die core 4 and the middle die 5; form a support strip 23 through the notches 51 on the middle die 5; and form an outer layer 22 through the gap between the middle die 5 and the die sleeve 6.

[0039] Specifically, the stranding core 1 is in Figure 2It moves leftward in traction, and the material is continuously extruded from the port of the extrusion die onto the cable core 1 that is under traction and moving. From the perspective of the radial cross-section, as Figure 3 shown, the middle die 5 presents an annular shape with a notch 51. Each radial protrusion part formed by the notch 51 can separate the material flow during the extrusion process. Together with the die core 4 and the die sleeve 6, the extruded plastic forms a cavity, and the material allowed to flow out at the notch 51 becomes the support strip 23. From the perspective of the axial cross-section, as Figure 2 shown, the middle die 5 is located between the die core 4 and the die sleeve 6. The material flowing out from the inner and outer gaps becomes the inner layer 21 and the outer layer 22 on both sides of the support strip 23.

[0040] In this embodiment, the gaps between the die core 4 and the middle die 5, and between the middle die 5 and the die sleeve 6 are both tapered gaps that gradually converge along the set direction. When the material in the gaps is extruded onto the cable core 1, not only the extrusion thickness is limited by this tapered structure, but also when passing through this tapered structure, it will be further pressed onto the cable core 1, making the extrusion process more stable and reliable. The notch 51 on the middle die 5 is a sloped notch that gradually approaches the die core 4 along the set direction. Figure 2 As shown by the line in the middle of the middle die 5, in this sloped notch, the lower edge of the end at the extrusion material outlet is still separated from the gap between the die core 4 and the middle die 5 by 1 mm to 2 mm, as Figure 2 shown by the left-end structure of the middle die 5.

[0041] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various variations and improvements can be made without departing from the spirit and essence of the present invention, and these variations and improvements are also regarded as the protection scope of the present invention.

Claims

1. A light armored power cable, characterized in that: It includes a stranded core (1), a buffer layer (2) and a sheath layer (3). The buffer layer (2) includes an inner layer (21), an outer layer (22) and support bars (23). The inner layer (21) is sleeved outside the stranded core (1). The outer layer (22) is sleeved outside the inner layer (21) with a gap therebetween. The cross-section of the support bar (23) is rectangular. The support bar (23) is arranged axially along the cable between the gaps of the inner layer (21) and the outer layer (22), and the inner and outer edges thereof respectively abut and connect to the inner layer (21) and the outer layer (22), so as to form a cavity between the inner layer (21) and the outer layer (22). The cross-section of the cavity is in an arc-shaped strip structure. The sheath layer (3) is coated outside the buffer layer (2).

2. The lightweight armored power cable according to claim 1, characterized in that: There are 6 - 10 support bars (23) arranged circumferentially around the cable. The cross-section width of the support bar (23) is 5 - 10 mm, and the height is 5 - 10 mm.

3. The light armored power cable according to claim 1, characterized in that: The inner layer (21), the outer layer (22) and the support bars (23) of the buffer layer (2) are an integral structure that is co-extruded outside the stranded core (1) by an extrusion method.

4. The light armored power cable according to claim 1, wherein: The stranded core (1) includes insulated cores (11) and a tape layer (12). The tape layer (12) is a flexible material layer with elasticity and is arranged outside the insulated cores (11) by a winding method.

5. The lightweight armored power cable according to claim 4, characterized in that: The winding overlap rate of the tape layer (12) is 10% - 50%.

6. The light armored power cable according to claim 4, characterized in that: The stranded core (1) further includes a filling layer (13), and the filling layer (13) is filled between the insulated cores (11) and the tape layer (12).

7. The light armored power cable according to claim 6, wherein: The insulated core (11) includes a conductive core (111) and an insulating layer (112) coated outside the conductive core (111). There are multiple insulated cores (11), and each insulated core (11) is stranded into a bundle. The filling layer (13) is filled in the gaps between the insulated cores (11) and the gaps between the insulated cores (11) and the tape layer (12) to support the tape layer (12) and ensure the roundness of the cable.

8. A buffer layer extrusion die, characterized in that: For extruding the buffer layer (2) of the lightweight armored power cable described in claim 3, the buffer layer extrusion die includes a die core (4), a middle die (5) and a die sleeve (6). The die core (4), the middle die (5) and the die sleeve (6) are all in a cylindrical structure. The central hole of the die core (4) allows the stranded core (1) to penetrate. There are notches (51) evenly distributed around the axis on the middle die (5). The die core (4), the middle die (5) and the die sleeve (6) are coaxially sleeved with gaps from inside to outside in sequence, and each gap communicates with the extrusion material inlet of the buffer layer (2). The ports of each gap serve as extrusion material outlets. During the extrusion process, the stranded core (1) moves in a set direction to form the inner layer (21) outside the stranded core (1) penetrating into the die core (4) through the gap between the die core (4) and the middle die (5); form the support bars (23) through the notches (51) on the middle die (5); and form the outer layer (22) through the gap between the middle die (5) and the die sleeve (6).

9. The buffer layer extrusion die according to claim 8, characterized in that: The gaps between the die core (4) and the middle die (5), and between the middle die (5) and the die sleeve (6) are both tapered gaps that gradually converge in the set direction. The notch (51) on the middle mold (5) is a sloped notch that gradually approaches the mold core (4) along a set direction.

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