Processing technology of high-cold-resistant special cable for control system and cable thereof

Abstract

The application discloses a kind of high cold-resistant control system special cable and its processing technology, its cable structure is a kind of high cold-resistant control system special cable, from inside to outside in turn includes insulated core, inner liner, shielding layer and outer sheath, the insulated core is at least two, insulated core from inside to outside in turn is conductor, tape and insulating layer, insulated core is twisted with each other, and filling rope is filled in twisted gap;The shielding layer inside and outside two sides are respectively provided with wrapping layer, the insulating layer uses cold-resistant heat-resistant ethylene-propylene rubber material, and the outer sheath uses irradiation ethylene-propylene rubber material.The application adopts the scheme that insulated core is twisted and then outer layer is coated with sheath layer, and the insulating layer of insulated core and the outer sheath material are all used with high cold-resistant ethylene-propylene rubber material, can effectively maintain the performance of insulating layer and outer sheath material when facing high cold environment, to improve the electrical performance of cable in high cold environment.

Description

Technical Field

[0001] The invention relates to a special cable processing technology for a highly cold-resistant control system and the cable thereof, belonging to the technical field of cable preparation. Background Art

[0002] Systems operating in extreme environments place high demands on cable cold resistance. Sudden temperature changes often lead to material embrittlement, breakage, and cracking of the insulation layer. These problems can degrade the cable's electrical performance, impacting the overall stability and reliability of the control system. In a typical cable structure, the conductor's insulation layer and outer sheath material, as well as the uniformity between these layers, significantly impact the cable's overall temperature resistance in cold regions. Specifically, the material's inherent temperature resistance affects the cable's overall cold resistance, while the eccentricity of the cold-resistant layer itself affects local cold resistance. The main challenges currently facing the industry involve improving the material's cold resistance and improving the uniformity of finished products using specific materials. Summary of the Invention

[0003] In order to solve the problems in the above-mentioned background technology, the present invention provides a special cable processing technology and cable for a highly cold-resistant control system.

[0004] The cable structure in the technical solution for achieving the purpose of the present invention is: a special cable for a highly cold-resistant control system, which includes, from the inside to the outside, an insulating core, an inner lining layer, a shielding layer and an outer sheath. There are at least two insulating cores, and the insulating cores are, from the inside to the outside, a conductor, a wrapping tape and an insulating layer. The insulating cores are twisted with each other, and the twisted gaps are filled with filling ropes; winding layers are respectively provided on the inner and outer sides of the shielding layer, the insulating layer is made of cold-resistant and heat-resistant EPDM rubber material, and the outer sheath is made of irradiated EPDM rubber material.

[0005] The present application discloses a special cable for a highly cold-resistant control system, which adopts a scheme in which the insulating core is twisted and then covered with an outer sheath layer. The insulating layer and the outer sheath of the insulating core are both made of EPDM rubber material with high cold resistance. When facing a high-cold environment, the performance of the insulating layer and the outer sheath material can be effectively maintained, thereby improving the electrical performance of the cable in a high-cold environment.

[0006] As an optional solution of the present application, the filling rope is a hemp rope, the wrapping tape is a thin flame-retardant tape, and the shielding layer is a tinned copper wire braided layer. The thin flame-retardant tape can prevent short circuit and fire when cracks appear in the cable. The tinned copper wire braided layer can reduce the corrosion of the internal copper wire in low temperature and snow water environment. At the same time, it can serve as a shielding layer for electromagnetic interference and radio frequency interference, protecting the internal signal transmission of the cable from the influence of external electromagnetic fields, thereby improving the stability and integrity of the signal.

[0007] The preparation process of the above-mentioned cable specifically includes the following steps:

[0008] S1: Prepare the insulated wire core and twist it;

[0009] S2: Wrap the inner lining and lay the inner shielding layer;

[0010] S3: Extrusion of the outer sheath; the S3 extrusion process uses a semi-extrusion die, and the outer sheath is extruded using a 120 extrusion sheath and a double-thread screw. The thickness of the outer sheath at the thinnest point is not less than 85% of the average thickness. After extrusion, it is first irradiated and then fully cooled in a cooling water tank for curing;

[0011] The semi-extrusion die

[0012] Core diameter d1 = sheath front diameter d0 ± 0.2mm; core sizing area l = (0.8~1.0) * d1, core outer cone angle α2 = (30~40)°;

[0013] The inner cone angle of the die sleeve is δ = (35~45)°;

[0014] The inner diameter of the die sleeve d3 = the nominal diameter of the finished product d2 + (0.11~0.13) mm;

[0015] Die sleeve sizing area l1 = (1.2~1.3) * d3.

[0016] The above-mentioned processing technology is simple, and the above-mentioned preparation technology can effectively save preparation time and thus reduce production costs.

[0017] The above-mentioned extrusion process uses a double-threaded screw and a semi-extrusion die. This combination can effectively prevent the sheath or cable core from sticking when extruding rubber materials. The sheath is easier to peel off, the eccentricity of the sheath is lower, the roundness of the cable is better, the structure is more compact, and the outer diameter is more precisely controlled. The out-of-roundness can be controlled to about 6%. The electrical performance of the cable is better under this out-of-roundness.

[0018] In the actual production process, oversized mold core and mold sleeve will lead to uneven extrusion thickness, poor roundness and large fluctuations in outer diameter. The outer taper angle of the mold core and the inner taper angle of the mold sleeve have a significant impact on the extrusion pressure. The angle between the mold core and the mold sleeve is the mold angle. When the mold angle is too large, it will lead to excessive extrusion pressure, material accumulation in the sleeve, resulting in mold jamming, which will seriously affect production continuity.

[0019] The preparation steps of the insulated wire core are:

[0020] A1: Wrap the tape around the outer layer of the conductor;

[0021] A2: Extrude an insulation layer on the outer layer of the tape;

[0022] As an optional solution to the above scheme, a 65-layer continuous vulcanizer is used in the insulation layer extrusion process in step A2. The insulation layer thickness ranges from 1.0 to 1.2 mm, and the thickness range of the thinnest point is more than 90% of the average thickness. Tests have shown that within this range, the cold resistance of the cable can be effectively guaranteed and its performance uniformity can be improved.

[0023] Furthermore, in order to obtain optimal production parameters, the outer cone angle α2 of the mold core is 36°, and the inner cone angle δ of the mold sleeve is 38°.

[0024] During the extrusion process of the outer sheath, the extrusion temperature is 100~135℃. After the extrusion is completed, it is first irradiated and then cooled. The cooling tank is ≥10m, and the irradiation parameters are a dose of 0.8-0.9 m / min / mA, an irradiation energy of 3.0 MeV, and a beam current of 20 mA. The irradiation parameters will affect the mechanical strength, cold resistance and aging resistance of the extruded material, effectively avoiding embrittlement of the material at low temperatures, thereby improving the tolerance of the outer sheath in high-cold environments and extending the product life.

[0025] The formula of the insulating layer is 100 parts of EPDM rubber matrix, 50 parts of talc, 60 parts of calcium carbonate, 8 parts of paraffin oil, 1 part of silane, 5 parts of paraffin, and 5 parts of zinc oxide. The calcium carbonate and silane components in the above ingredients are beneficial to improving the wear resistance and tear resistance of the finished product. The silane component is beneficial to improving the interface bonding performance between the inorganic filler and the organic polymer, further improving the tear resistance of the product. The synergistic effect of the two can improve the material's resistance to cracking in low temperature environments, thereby extending the product life.

[0026] By adopting the above technical solution, the present invention has the following beneficial effects:

[0027] (1) The processing technology of a special cable for a high cold-resistant control system of the present application specifies the matching relationship between the die core and the die sleeve, strictly limits its die angle, and effectively prevents the die jamming problem caused by the accumulation of extrusion pressure. Compared with other extrusion structures, its production continuity is better; during the processing, the extrusion temperature and irradiation parameters during the extrusion process are specified, which can effectively balance the mechanical properties, cold resistance and anti-aging properties of the material and effectively avoid the low-temperature embrittlement of the material.

[0028] (2) The processing technology of a special cable for a high cold-resistant control system in this application has formulated the extrusion method and thickness of each layer used in the extrusion process, which can effectively prevent adhesion during the extrusion process. It is easier to peel off after extrusion, and the final product has better roundness, more compact structure, and more stable electrical performance.

[0029] (3) The special cable for a highly cold-resistant control system of the present application adopts a scheme in which the insulating core is twisted and then covered with a sheath layer, and the insulation layer and the outer sheath of the insulating core are made of EPDM rubber material with high cold resistance. When facing a high-cold environment, the performance of the insulation layer and the outer sheath material can be effectively maintained, thereby improving the electrical performance of the cable in a high-cold environment.

[0030] (4) The special cable for a highly cold-resistant control system of the present application uses a thin flame-retardant tape as a wrapping tape and a tinned copper wire braided layer as a shielding layer. The medium-thin flame-retardant tape can prevent short circuit fire when cracks appear in the cable. The tinned copper wire braided layer can reduce the corrosion of the internal copper wire in low temperature and snow water environment. At the same time, it can serve as a shielding layer for electromagnetic interference and radio frequency interference, protecting the internal signal transmission of the cable from the influence of external electromagnetic fields, thereby improving the stability and integrity of the signal.

[0031] (5) The calcium carbonate in the insulation layer formula of the special cable for a high cold-resistant control system of the present application is beneficial to improving the wear resistance and tear resistance of the finished product, and the silane component is beneficial to improving the interface bonding performance between the inorganic filler and the organic polymer, further improving the tear resistance of the product. The synergistic effect of the two can improve the material's resistance to cracking in a low-temperature environment, thereby extending the product life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings, wherein

[0033] Figure 1 It is a structural schematic diagram of the present invention;

[0034] Figure 2 A schematic diagram of a semi-extrusion mold core and a semi-extrusion mold sleeve of the present invention;

[0035] Figure 3 It is a schematic diagram of the production process of the present invention;

[0036] The reference numerals in the accompanying drawings are:

[0037] Insulated core 1, conductor 11, wrapping tape 12, insulation layer 13, shielding layer 2, outer sheath 3, filling rope 4, and wrapping layer 5. DETAILED DESCRIPTION

[0038] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0042] In the description of the embodiments of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0043] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", "connection", and "connection" 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, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The present invention is further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are not intended to limit the scope of protection of the present invention.

[0044] (Example 1)

[0045] Figure 1This is a simplified structural diagram of a special cable for a highly cold-resistant control system of the present application, which specifically includes an insulating core 1, a shielding layer 2 and an outer sheath 3 from the inside to the outside. There are at least two insulating cores 1, and the insulating cores 1 are composed of a conductor 11, a wrapping tape 12 and an insulating layer 13 from the inside to the outside. The insulating cores 1 are twisted with each other, and the twisted gaps are filled with filling ropes 4; the shielding layer 2 is provided with a wrapping layer 5 on both sides, the insulating layer 13 is made of cold-resistant and heat-resistant EPDM rubber material, and the outer sheath 3 is made of irradiated EPDM rubber material.

[0046] The filling rope 4 is a hemp rope, the wrapping tape 12 is a thin flame-retardant tape, and the shielding layer 2 is a tinned copper wire braided layer.

[0047] In the above structure, the braiding density of the tinned copper wire braided layer of the shielding layer 2 is ≥85%.

[0048] In the above structure, in order to improve the resistance of the shielding layer 2 and the outer sheath 3, which are prone to cracking due to severe cold, their components need to be adjusted.

[0049] The formula of the insulating layer is 100 parts of EPDM rubber matrix, 50 parts of talc powder, 60 parts of calcium carbonate, 8 parts of paraffin oil, 1 part of silane, 5 parts of paraffin and 5 parts of zinc oxide.

[0050] After testing, using the above formula, the temperature range of the insulation layer is -50~90℃, and the insulation resistance is ≥500MΩ·km.

[0051] Figure 3 This is a schematic diagram of the production process of a special cable for a highly cold-resistant control system in this application. The specific production sequence is conductor, insulation, cabling, shielding, wrapping, outer sheath, irradiation, cooling, and winding.

[0052] The number of insulated cores is 19 and the nominal cross-sectional area of ​​the conductor is 2.5mm 2 As the target parameters, the following parameters were obtained by testing the tube extrusion, extrusion, and semi-extrusion dies under the above formula:

[0053] ;

[0054] It can be seen that the eccentricity of the product is lower when the semi-extrusion extrusion method is adopted, so the semi-extrusion structure design is adopted. Its specific parameters and test results are as follows:

[0055]

[0056] After testing, when the outer cone angle of the mold core α2=36° and the inner cone angle of the mold sleeve δ=38°, the eccentricity reaches 6% and the cable appearance is optimal.

[0057] Its specific structure is as follows Figure 2As shown, a is a semi-extrusion mold core structure; b is a semi-extrusion mold sleeve structure.

[0058] The processing technology of a special cable for a highly cold-resistant control system of the present application comprises the following steps:

[0059] S1: Prepare an insulated wire core 1 and twist it;

[0060] S2: Wrap the inner lining layer 2 and lay the inner shielding layer 2;

[0061] S3: extrusion of outer sheath 3;

[0062] Specifically, the steps for preparing the insulated wire core 1 are:

[0063] A1: Wrap the tape 12 around the outer layer of the conductor 11;

[0064] A2: Extruding an insulating layer 13 on the outer layer of the wrapping tape 12;

[0065] In the step A2, a 65-degree continuous vulcanizing machine is used in the extrusion process of the insulating layer 13. The thickness of the insulating layer ranges from 1.0 to 1.2 mm, and the thickness of the thinnest point ranges from 90% to more than the average thickness.

[0066] A semi-extrusion die is used in the S3 extrusion process, and a 120 extrusion sheath and a double-thread screw are used in the extrusion process of the outer sheath 3. The extrusion temperatures are 100°C, 113°C, 126°C, 132°C, 136°C, and 135°C. The thickness of the outer sheath 3 at the thinnest point is not less than 85% of the average thickness. After extrusion, the outer sheath 3 is cured by irradiation followed by cooling.

[0067] The extrusion temperature of the outer sheath 3 during the extrusion process is 100-135° C. After the extrusion is completed, the irradiation parameters are a dose of 0.8-0.9 m / min / mA, an irradiation energy of 3.0 MeV, and a beam current of 20 mA.

[0068] During the above operation, the sheath is extruded and passed through the cooling water tank for at least 10 meters to ensure that the cable is fully cooled. When winding the cable, a mixture of talcum powder and rubber release agent (the ratio of talcum powder and rubber release agent is 1:2) is evenly applied on the surface of the cable sheath to prevent the cable from sticking after winding.

[0069] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A processing technology for special cables for high cold-resistant control systems, characterized in that The following steps are involved: S1: preparing an insulated wire core (1) and twisting it; S2: Wrap the first wrapping layer (5) and lay the inner shielding layer (2) and then wrap the second wrapping layer (5); S3: extrusion of outer sheath (3); The S3 extrusion process uses a semi-extrusion die, and the outer sheath (3) uses a 120 extrusion sheath and a double-thread screw. The thickness of the outer sheath (3) at the thinnest point is not less than 85% of the average thickness. After extrusion, the outer sheath is first irradiated and then fully cooled in a cooling water tank for curing. The semi-extrusion die Core diameter d1 = sheath front diameter d0 ± 0.2mm; core sizing area l = (0.8~1.0) * d1, core outer cone angle α2 = (30~40)°; The inner cone angle of the die sleeve is δ = (35~45)°; The inner diameter of the die sleeve d3 = the nominal diameter of the finished product d2 + (0.11~0.13) mm; Die sleeve sizing area l1 = (1.2~1.3) * d3.

2. The processing technology of a special cable for a high cold-resistant control system according to claim 1 is characterized in that The steps for preparing the insulated wire core (1) are: A1: Wrap the tape (12) around the outer layer of the conductor (11); A2: Extruding an insulating layer (13) on the outer layer of the wrapping tape (12); In the step A2, a 65-degree continuous vulcanizing machine is used in the extrusion process of the insulating layer (13), and the thickness of the insulating layer ranges from 1.0 to 1.2 mm, and the thickness range of the thinnest point is more than 90% of the average thickness.

3. The processing technology of a special cable for a high cold-resistant control system according to claim 1 is characterized in that The outer cone angle of the mold core is α2=36°, and the inner cone angle of the mold sleeve is δ=38°.

4. The processing technology of a special cable for a highly cold-resistant control system according to claim 1 is characterized in that: The extrusion temperature of the outer sheath (3) during the extrusion process is 100-135°C. After the extrusion is completed, the irradiation parameters are a dose of 0.8-0.9 m / min / mA, an irradiation energy of 3.0 MeV, and a beam current of 20 mA. After the irradiation is completed, it passes through a cooling tank for ≥10m.

5. A special cable for a highly cold-resistant control system, prepared by the processing technology of a special cable for a highly cold-resistant control system according to claim 1, characterized in that: The invention comprises, from the inside to the outside, an insulating core (1), a shielding layer (2) and an outer sheath (3), wherein the number of the insulating cores (1) is at least two, and the insulating cores (1) comprise, from the inside to the outside, a conductor (11), a wrapping tape (12) and an insulating layer (13), the insulating cores (1) are twisted together, and the twisted gaps are filled with a filling rope (4); the shielding layer (2) is provided with a wrapping layer (5) on both the inside and outside, respectively, the insulating layer (13) is made of a cold-resistant and heat-resistant EPDM rubber material, and the outer sheath (3) is made of an irradiated EPDM rubber material.

6. The special cable for a highly cold-resistant control system according to claim 5, characterized in that: The filling rope (4) is a hemp rope, the wrapping tape (12) is a thin flame-retardant tape, and the shielding layer (2) is a tinned copper wire braided layer.

7. The special cable for a highly cold-resistant control system according to claim 5, characterized in that: The formula of the insulating layer is 100 parts of EPDM rubber matrix, 50 parts of talc powder, 60 parts of calcium carbonate, 8 parts of paraffin oil, 1 part of silane, 5 parts of paraffin and 5 parts of zinc oxide.

Images