Durable drag chain cable

Abstract

The utility model discloses a durable drag chain cable, which comprises a cable core formed by arranging four groups of wire units in an array, reinforcing cores respectively filled in the center and the periphery of the cable core, and a sheath coated outside the cable core, each wire unit comprises three wires formed by wrapping an insulating layer outside a conductor, a filling core is arranged on the periphery of the three wires in a filling mode, and the three wires and the filling core are twisted in a compound mode to form the wire unit. The wires and the filling cores are subjected to compound stranding forming to obtain the wire units, the reinforcing cores are arranged at the center and the periphery of the cable core formed by the four groups of wire units, and the sheath is coated outside the cable core, so that the overall tensile strength of the cable is improved, the stranding coefficient is improved, the flexibility of the cable is improved, and the flexing resistance of the cable is improved by increasing the hot backup of the wire cores. And the reliability and durability of the cable are improved.

Description

Technical Field

[0001] This utility model belongs to the field of cable technology, specifically relating to a durable drag chain cable. Background Technology

[0002] In various equipment applications such as overhead cranes, gantry cranes, and hoists, mobile drag chain cables are required to transmit power and signals. These cables are subjected to frequent bending, tensile stress, strain, and friction during use. Under repeated stress and strain, the cables are prone to damage. Failure of the drag chain cable during equipment operation poses a significant accident risk, thus requiring regular replacement. During cable replacement, the equipment needs to be stationary; frequent cable replacements result in substantial economic losses. Therefore, the durability requirements for drag chain cables are increasingly stringent in practical applications. Utility Model Content

[0003] The purpose of this invention is to provide a durable drag chain cable to solve the problem of drag chain cables having poor durability and requiring frequent replacement.

[0004] This utility model is achieved through the following technical solution:

[0005] Durable drag chain cable includes a cable core formed by an array of four sets of conductor units, reinforcing cores are filled at the center and periphery of the cable core, and a sheath is provided to cover the cable core.

[0006] The conductor unit comprises three conductors formed by covering the conductor with an insulating layer, and a filler core is filled around the three conductors. The three conductors and the filler core are twisted together to form the conductor unit.

[0007] In some embodiments, the conductors of the three conductors in the conductor unit are stranded in the same direction, and the stranding direction of the conductors is opposite to the twisting direction of the conductors.

[0008] In some embodiments, the pitch ratio of the stranded conductor bundle is not greater than 20 times, and the pitch ratio of the stranded conductor unit is not greater than 14 times.

[0009] In some embodiments, the reinforcing core and the filling core are made of aramid fiber.

[0010] In some embodiments, the diameter of the reinforcing core is not less than 0.8 mm, and the diameter of the filling core is not less than 0.6 mm.

[0011] In some embodiments, the sheath includes an inner sheath, a reinforcing sheath, and an outer sheath arranged sequentially from the inside to the outside;

[0012] The inner and outer sheaths are made of polyether-type polyurethane elastomer by extrusion molding.

[0013] The reinforcing sleeve is made of aramid fiber woven into shape, with a weaving angle of 40° to 50° and a weaving density of not less than 60%.

[0014] In some embodiments, a repair sleeve is provided between the reinforcing sleeve and the outer sheath. The repair sleeve has a plurality of cavities evenly distributed along its circumference. Repair capsules are provided in the cavities and are filled with repair agent.

[0015] In some embodiments, the cavity is divided into two layers in the radial direction, and the two layers of cavity are staggered in the circumferential direction.

[0016] In some embodiments, the insulating layer is formed by extrusion molding of ethylene propylene rubber.

[0017] In some embodiments, in the same conductor unit, the insulation layer of each conductor has a different number of color stripes.

[0018] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0019] This utility model uses a method of twisting conductors and filler cores together to form conductor units. A reinforcing core is set in the center and periphery of the cable core composed of four sets of conductor units, and a sheath is set on the outside of the cable core. This improves the overall tensile strength of the cable, the twisting coefficient, and the cable's flexibility, flexural resistance, and drag chain performance. Furthermore, by increasing the thermal backup of the conductor core, the reliability and durability of the cable are improved.

[0020] The repair sleeve design allows for the rapid repair of cracks in the outer sheath, restoring its integrity and effectively preventing moisture and dust from entering the cable. This avoids damage to the core due to external damage to the outer sheath, thereby extending the cable's service life. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a durable drag chain cable structure according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of a durable drag chain cable structure according to another embodiment of the present invention.

[0024] in:

[0025] 1. Conductor, 2. Color stripe, 3. Insulation layer, 4. Filler core, 5. Reinforcing core, 6. Inner sheath, 7. Reinforcing sleeve, 8. Outer sheath, 9. Repair sleeve, 91. Cavity, 92. Repair capsule. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0027] Based on the typical usage scenarios of drag chain cables, in addition to bearing a certain amount of tension during use, the cables also have to withstand reciprocating motion as they pass through the drum and the pulley of the tensioning device. Therefore, the main causes of cable failure include fatigue fracture of the conductor, tensile elongation of the conductor, and friction damage to the cable.

[0028] Based on the analysis of the causes of cable failure, this invention optimizes the cable structure by increasing the overall tensile strength of the cable, improving the twisting coefficient, and adding thermal backup for the conductors, thereby improving the durability and reliability of the cable.

[0029] According to the stress-fatigue curve equation, we know that:

[0030] ;

[0031] Where N is the fatigue limit stress The maximum number of cycles that will not result in fatigue damage;

[0032] m is an exponent, and the exponent is a constant. The bending stress of copper is 9, and the contact stress is 8.

[0033] The loop base is used when the number of iterations is greater than 1. When this occurs, it is considered an infinite loop;

[0034] This represents the ultimate fatigue stress under the cycle base.

[0035] Therefore, to improve the high-cycle fatigue life of cables, it is necessary to increase the ultimate fatigue stress of the cables, that is, the overall tensile strength of the cables.

[0036] The conductor 1 of the cable is made of type 6 soft copper conductor, and the conductor strands are stranded in the same direction. The conductor 1 is covered with an insulation layer 3 to obtain a wire. Three wires are used and a filler core 4 is arranged around the three wires. The wires and filler core 4 are twisted together with a small pitch and equal pitch ratio to obtain a wire unit, so as to improve the flexibility, bending resistance and drag chain resistance of the cable.

[0037] The stranded wires are laid out using a standard stranding method, with left-hand stranding at a pitch of no more than 20 times the pitch diameter; the conductors and filler cores are then right-hand twisted into conductor units at a pitch of 14 times the pitch diameter to improve the conductor's flexibility and resistance to bending and drag chain performance.

[0038] The filling core 4 is made of aramid fiber material. (Refer to...) Figure 1 In the conductor unit, a filler core 4 is provided between adjacent conductors on the periphery of the conductor unit. The diameter of the filler core is not less than 0.6 mm.

[0039] Insulation layer 3 uses EPDM rubber with a medium ethylene content as the skeleton material, and employs a composite vulcanization system of crosslinking agent WY988 and organic peroxide (DCP). The combination of these two materials generates two different types of chemical crosslinking bonds: -S-(CH)-S- bonds (x=1 or 2) and carbon-carbon bonds. Among them, -S-(CH)-S- bonds have anti-reduction and anti-fatigue properties, while carbon-carbon bonds have excellent aging resistance. The synergistic effect of the two crosslinking bonds gives the rubber excellent physical properties. At the same time, by combining nanomaterials and functional materials, the insulation layer possesses excellent mechanical strength, bending resistance, heat resistance, winding resistance, and electrical properties.

[0040] An interlocking, closed-loop rubber mixing production line is used to produce ethylene propylene rubber insulation material via a three-stage reverse mixing process, ensuring the cleanliness and excellent performance of the insulation material. The resulting ethylene propylene rubber insulation material exhibits excellent electrical properties (volume resistivity of not less than 1×10⁻⁶ at 20℃). 13 Ω.m), cold resistance (working temperature not less than -55℃), flexibility, torsion resistance and flexural resistance.

[0041] The dual-machine continuous vulcanization production line with a length-to-diameter ratio of 16 ensures that the insulation layer is uniform, dense, and round, resulting in excellent insulation performance.

[0042] The cable uses four sets of conductor units, which are arranged in a rectangular array to form the cable core. Reinforcing cores 5 are arranged in the center and around the four sets of conductor units.

[0043] The cable is formed using a 630 cage-type cable forming machine. The cage stranding machine can fully untwist the cable core, reducing the occurrence of internal stress. Aramid fiber material is filled into the center and periphery of the cable core to make the force on each conductor unit uniform, avoid residual stress, and improve the flexibility of the cable core.

[0044] Reinforcing core 5 is made of aramid fiber material. (Refer to...) Figure 1 Reinforcing cores 5 are installed at the center of the four sets of conductor units and between adjacent conductor units on the periphery of the cable core. The diameter of the reinforcing core is not less than 0.8 mm.

[0045] A sheath is installed outside the cable core, which includes an inner sheath 6, a reinforcing sheath 7, and an outer sheath 8 arranged sequentially from the inside to the outside.

[0046] The inner sheath 6 is made of polyether-type polyurethane elastomer by high-pressure extrusion molding, which fills the gaps on the outer edge of the cable core, stabilizes the cable core structure, and provides effective support for each conductor unit.

[0047] The reinforcing sleeve 7 is made of aramid fiber and is woven into the inner sheath 6 with a specific braiding pitch and braiding angle. The braiding angle of the reinforcing sleeve 7 is 40° to 50°, and the braiding density is not less than 60%, in order to improve the mechanical strength of the cable and extend its service life.

[0048] The use of aramid fiber-formed filler core, reinforcing core, and reinforcing sleeve can effectively improve the mechanical strength and torsional resistance of cables.

[0049] The outer sheath 8 is made of polyether-type polyurethane elastomer by high-pressure extrusion molding and is installed on the outside of the reinforcing sleeve 7.

[0050] The outer and inner sheaths made of polyether-type polyurethane elastomer not only have good mechanical properties (tensile strength not less than 30 N·mm) 2 It has an elongation at break of not less than 300%, and also has excellent wear resistance, oil resistance, acid and alkali resistance, cold resistance (working temperature not less than -55℃), salt spray resistance, and weather resistance, enabling the cable to adapt to the harsh operating environment and conditions of various equipment.

[0051] Reference Figure 1 In the same conductor unit, the insulation layer of each conductor has a different number of color stripes 2. During insulation layer forming, the color stripes are formed within the insulation layer using an injection molding machine, extending from the middle of the insulation layer to its outer surface. By setting different numbers of color stripes on different conductors within the same conductor unit, the conductors are distinguished, facilitating wiring. For example... Figure 1 As shown, in each group of wire units, wires with different numbers of color bars are arranged clockwise, for example, sequentially with 1 color bar, 2 color bars, and 3 color bars in a clockwise direction. Arranging the wires in each group of wire units in the same pattern ensures that the wiring operation follows the same procedure, thus improving wiring efficiency.

[0052] Reference Figure 2 In some other embodiments of this utility model, a repair sleeve 9 is provided between the reinforcing sleeve 7 and the outer sheath 8. Several cavities 91 are evenly distributed along the circumference of the repair sleeve 9. Repair capsules 92 are provided in the cavities 91 and are filled with repair agent.

[0053] When cracks or damage appear on the surface of the outer sheath, the repair capsule ruptures, releasing the repair agent inside. This agent reacts with moisture and oxygen, quickly solidifying to fill the cracks and restore the integrity of the outer sheath. This effectively prevents moisture and dust from entering the cable, avoiding damage to the conductors due to external damage to the outer sheath, thus extending the cable's lifespan.

[0054] Repair agents can be polyurethane-based, epoxy resin-based, silicone rubber-based, acrylate-based, or hot melt adhesive-based, etc. These materials have good adhesion and rapid curing properties, and are well compatible with polyether-based polyurethane elastomer materials. The outer shell of the repair capsule can be made of polymer materials to ensure good mechanical strength and stability.

[0055] The repair capsule 92 is typically designed to have a very small size, generally between tens and hundreds of micrometers, enabling uniform distribution within the cavity. Self-healing of materials through microencapsulation technology is currently used in fields such as electronic devices, automotive parts, and cables. This invention does not involve improvements to the microcapsules.

[0056] During the extrusion molding of the repair sleeve, a hollow structure is formed; the repair capsule can be filled into the cavity using methods such as spraying or injection, ensuring that the repair capsule can evenly fill the cavity. (Refer to...) Figure 2 The cavity has an arc-shaped structure arranged along the circumference.

[0057] In some embodiments, the cavity 91 is divided into two layers in the radial direction, and the two layers of cavities are staggered in the circumferential direction, so that the cavities can substantially cover the entire circumference of the repair sleeve in the circumferential direction, thereby enabling the repair of cracks at any location on the outer sheath. By configuring the cavity into two layers, while achieving coverage of the entire circumference of the repair sleeve, the spacing between adjacent cavities located in the same radial direction can be increased, avoiding any impact of the cavity configuration on the torsional resistance of the outer sheath.

[0058] The cavity 91 is filled with nano-scale aerogel or microporous foam material to fill the gaps inside the cavity. This allows the repair agent to be squeezed into the crack when the repair capsule ruptures, thus better exerting the repair agent's effect. At the same time, the nano-scale aerogel and microporous foam material have good flexibility and elasticity, and can adapt well to the bending and torsional movements of the cable.

[0059] Meanwhile, the cavity and the filling of the cavity with repair capsules, nano-aerogel or microporous foam materials can form a buffer layer on the repair sleeve, which can provide a certain buffer protection for the cable when it is subjected to external impact loads.

[0060] Nanoscale aerogels and microporous foam materials can be filled into cavities in the form of powder, granules or foam, for example, by vacuum filling, injection filling or pneumatic filling.

[0061] The repair sleeve uses the same material as the outer sheath, such as polyether-type polyurethane elastomer, so that it can better form an integral structure with the outer sheath.

[0062] According to the requirements for cables used in robot systems in 2 PfG 2577 / 08.16 and the structural design scheme of durable drag chain cables, 2 PfG 2577 IRS05V2V2-H 12×0.3 Class Ⅱ cables were manufactured, and the mobile life of the cables was tested according to the requirements of rapid bending test, drag chain test and 90° bending test specified in 2 PfG 2577 / 08.16. The performance test data are shown in Table 1.

[0063] The performance test results show that the cable durability in this embodiment meets the specifications and manufacturer's performance requirements for cables.

[0064] Table 1 Cable performance test data for this embodiment

[0065]

[0066] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0067] Furthermore, the use of terms such as "horizontal" or "vertical" in the description of this utility model does not imply that the component is required to be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0068] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0069] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A durable drag chain cable, characterized in that, It includes a cable core formed by an array of four sets of conductor units, with reinforcing cores filling the center and periphery of the cable core, and a sheath covering the outside of the cable core; The conductor unit includes three conductors formed by covering the conductor with an insulating layer, and a filler core is filled around the three conductors. The three conductors and the filler core are twisted together to form the conductor unit. The conductors of the three conductors in the conductor unit are bundled together in the same direction, and the bundled direction of the conductors is opposite to the twisted direction of the conductors. The sheath comprises an inner sheath, a reinforcing sheath, and an outer sheath arranged sequentially from the inside out; the inner and outer sheaths are extruded from polyether-type polyurethane elastomer; the reinforcing sheath is woven from aramid fibers with a weaving angle of 40° to 50° and a weaving density of not less than 60%. A repair sleeve is provided between the reinforcing sleeve and the outer sheath. Several cavities are evenly distributed along the circumference of the repair sleeve. Repair capsules are provided in the cavities and filled with repair agent. The cavities are divided into two layers in the radial direction, and the two layers of cavities are staggered in the circumferential direction.

2. The durable drag chain cable according to claim 1, characterized in that, The pitch ratio of the stranded conductor bundle is no greater than 20, and the pitch ratio of the stranded conductor unit is no greater than 14.

3. The durable drag chain cable according to claim 1, characterized in that, The reinforcing core and filling core are made of aramid fiber.

4. The durable drag chain cable according to claim 1 or 3, characterized in that, The diameter of the reinforcing core is not less than 0.8 mm, and the diameter of the filling core is not less than 0.6 mm.

5. The durable drag chain cable according to claim 1, characterized in that, The insulating layer is made of ethylene propylene rubber by extrusion molding.

6. The durable drag chain cable according to claim 1, characterized in that, Within the same conductor unit, each conductor has a different number of colored stripes inside its insulation layer.

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