A low-noise coaxial cable integrated push forming method

Abstract

The present application relates to coaxial cable manufacturing technology field, especially to a kind of low-noise coaxial cable integrated push forming method, comprising: obtaining the single product particle size distribution corresponding to basic PTFE powder and the mixed particle size distribution corresponding to carbon-doped PTFE mixture;Based on the core wire bending eigenvalue, single product particle size distribution and mixed particle size distribution, the target thickness ratio of insulating layer and semi-conductive layer is determined, and the initial first thickness and the initial second thickness are determined based on the target thickness ratio;Based on the initial first thickness, the insulating filling layer of mold is filled with basic PTFE powder, and based on the initial second thickness, the semi-conductive filling layer of mold is filled with carbon-doped PTFE mixture, and the pre-pressing forming blank is obtained;Based on the set push parameters, the pre-pressing forming blank and the core wire are integrated and pushed to form, to obtain the target coating body.The present application can improve the anti-noise performance of cable, improve the quality and stability of finished product, and ensure the production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of coaxial cable manufacturing, and in particular to an integrated extrusion molding method for low-noise coaxial cables. Background Art

[0002] A cable that generates a pulse signal less than 5mV under the influence of external factors such as bending, vibration, impact, and temperature changes is called a low-noise cable. It can be used as a connecting line for sensors and other devices that transmit weak signals. It is widely used in the measurement of tiny signals in industry, medicine, national defense, and other fields.

[0003] Currently, low-noise coaxial cables primarily suppress friction noise by coating or extruding a semiconductive material onto the PTFE dielectric. Existing methods include coating a PTFE suspension and sintering it, and extruding a semiconductive polyethylene (PE) layer. These methods suffer from complex processes, poor bonding strength, easy delamination over long-term use, and unstable noise suppression.

[0004] Chinese patent publication number CN217544190U discloses a noisy coaxial cable, comprising a conductor and, sequentially wrapped around the conductor from the inside out, an insulating layer, a semiconductive layer, a shielding layer, and a sheath. The shielding layer comprises a first shielding layer located within and a second shielding layer located outside. The first shielding layer is formed by spirally wrapping a silver-plated copper flat tape, and the second shielding layer is woven from silver-plated round copper wire. The low-noise coaxial cable in this utility model utilizes a graphene semiconductive layer extruded on the surface of the polytetrafluoroethylene insulation layer, thereby reducing the noise of the coaxial cable.

[0005] The existing technology has the following problems:

[0006] It is difficult to ensure the uniformity and stability of the graphene layer by extruding a graphene semi-conductive layer on the surface of the polytetrafluoroethylene insulation layer. The use of a double-layer shielding structure increases the complexity of the manufacturing process, making it difficult to ensure the noise resistance of the cable, affecting the quality and stability of the finished product, and resulting in relatively low production efficiency. Summary of the Invention

[0007] To this end, the present invention provides an integrated extrusion molding method for a low-noise coaxial cable, which is used to overcome the problem in the prior art of extruding a graphene semi-conductive layer on the surface of a polytetrafluoroethylene insulation layer, making it difficult to ensure the uniformity and stability of the graphene layer, and thus making it difficult to ensure the anti-noise performance of the cable, affecting the quality and stability of the finished product.

[0008] To achieve the above-mentioned object, the present invention provides a low-noise coaxial cable integrated extrusion molding method, comprising:

[0009] Performing a bending deformation test on the core wire to obtain a core wire bending characteristic value of the core wire;

[0010] Mixing the conductive carbon powder with the basic PTFE powder based on a preset ratio to obtain a carbon-doped PTFE mixture, and obtaining a single product particle size distribution corresponding to the basic PTFE powder and a mixed particle size distribution corresponding to the carbon-doped PTFE mixture;

[0011] determining a target thickness ratio of the insulating layer to the semiconductive layer based on the core wire bending characteristic value, the single product particle size distribution, and the mixed particle size distribution, and determining an initial first thickness and an initial second thickness based on the target thickness ratio;

[0012] Filling the insulating filling layer of the mold with basic PTFE powder based on the initial first thickness, and filling the semi-conductive filling layer of the mold with a carbon-doped PTFE mixture based on the initial second thickness, and controlling the mold to perform pre-pressing molding with set pre-pressing parameters to obtain a pre-pressed blank;

[0013] Determining whether a preset standard is met based on a first intermediate thickness and a second intermediate thickness corresponding to the pre-pressed blank, and if so, determining and setting a pushing parameter based on the first intermediate thickness and the second intermediate thickness;

[0014] The pre-pressed blank and the core wire are integrally extruded based on the set extrusion parameters to obtain a target cladding body.

[0015] Furthermore, the bending deformation test process includes:

[0016] Fixing one end of the object to be measured and applying a preset bending force to the other end of the object to be measured so that the object to be measured is bent around a bending mold core to a preset bending angle, wherein the core diameter of the bending mold core is determined according to the measured diameter of the object to be measured;

[0017] Maintaining a preset time, and measuring the stretched length of the object to be measured after removing the preset bending force;

[0018] The bending characteristic value of the object to be measured is determined based on the initial length of the object to be measured and the stretched length.

[0019] Furthermore, the process of determining the target thickness ratio includes:

[0020] Determining a first particle size characteristic value based on the single product particle size distribution;

[0021] determining a second particle size characteristic value based on the mixed particle size distribution;

[0022] The target thickness ratio is determined based on the first particle size characteristic value and the second particle size characteristic value.

[0023] Furthermore, the process of determining the initial first thickness and the initial second thickness based on the target thickness ratio includes:

[0024] determining an initial first thickness based on the target thickness ratio and a standard thickness;

[0025] An initial second thickness is determined based on the target thickness ratio and the initial first thickness.

[0026] Furthermore, the set pre-compression parameter is determined based on the initial first thickness and the initial second thickness.

[0027] Furthermore, the process of determining the set preload parameters includes:

[0028] determining a first comparison coefficient based on a comparison result of the initial first thickness and the target first thickness;

[0029] determining a second comparison coefficient based on a comparison result of the initial second thickness and the target second thickness;

[0030] The set preload parameter is determined based on the first comparison coefficient, the second comparison coefficient, and a standard preload parameter.

[0031] Furthermore, the process of determining whether the preset standards are met includes:

[0032] determining a critical thickness ratio based on the intermediate first thickness and the intermediate second thickness;

[0033] Based on the comparison result of the critical thickness ratio and the preset thickness ratio, it is determined whether it meets the preset standard.

[0034] Furthermore, the process of determining the setting pushing parameters includes:

[0035] constructing a first thickness characterization curve based on the intermediate first thickness, the initial first thickness, and the target first thickness, and determining a first thickness characterization value based on the first thickness characterization curve;

[0036] constructing a second thickness characterization curve based on the intermediate second thickness, the initial second thickness, and the target second thickness, and determining a second thickness characterization value based on the second thickness characterization curve;

[0037] determining a comprehensive adjustment coefficient based on the first thickness characterizing value and the second thickness characterizing value;

[0038] The set pushing parameter is determined based on the comprehensive adjustment coefficient and the standard pushing parameter.

[0039] Furthermore, after obtaining the target coating body, the method further comprises:

[0040] Performing a bending deformation test on the target coating to obtain a coating bending characteristic value of the target coating;

[0041] Determining a braiding angle based on the bending characteristic value of the coating, and braiding the coating material around the target coating at the braiding angle to obtain a braided coating;

[0042] Obtaining the maximum deformation characteristic value of the braided sheath to determine the outer sheath thickness;

[0043] An outer protective sheath is prepared based on the outer protective sheath thickness, and the outer protective sheath is coated on the periphery of the braided coating body to obtain a low-noise coaxial cable.

[0044] Furthermore, the process of determining the outer protection thickness includes:

[0045] Marking a first point, a second point, and a midpoint between the first point and the second point on a predetermined length of the braided sheath;

[0046] Taking the middle point as the bending axis, the braided covering body is bent with a set bending radius;

[0047] Obtaining a maximum deformation area and a minimum deformation area within a preset length of the braided sheath to determine the maximum deformation characteristic value;

[0048] The outer protection thickness is determined based on the maximum deformation characteristic value and the diameter of the braided covering.

[0049] Compared with the prior art, the present invention has the beneficial effect of evaluating the bending resistance of the core wire by performing a bending deformation test on the core wire, determining the core wire bending characteristic value based on the test results, and accurately characterizing the core wire bending characteristics. By mixing conductive carbon powder with base PTFE powder according to a preset ratio and controlling the carbon powder dosage, the conductivity and mechanical properties of the carbon-doped PTFE mixture can be optimized. The target thickness ratio of the insulating layer to the semi-conductive layer is determined based on the core wire bending characteristic value, the particle size distribution of the individual products, and the particle size distribution of the mixed products. By comprehensively considering the core wire bending characteristics, the uniformity of the base PTFE powder, and the carbon-doped PTFE mixture, the thickness is rationally allocated to ensure the noise resistance of the cable during bending and use. By determining the initial first and second thicknesses based on the target thickness ratio, filling the mold with the base PTFE powder and the carbon-doped PTFE mixture based on these initial thicknesses, and controlling the mold to perform pre-pressing according to set pre-pressing parameters, material waste can be reduced, powder particles can be tightly bound, and the strength and uniformity of the pre-pressed blank can be improved. Pre-pressing can also reduce deformation and cracking that may occur during subsequent extrusion molding, thereby improving product quality. By checking the thickness after pre-pressing to ensure the stability and uniformity of the blank and adjusting the extrusion parameters based on the pre-pressed thickness, molding efficiency and product quality can be improved. Extruding the pre-pressed blank and core wire in an integrated manner based on the set extrusion parameters eliminates delamination interfaces, improves the cable's stability and noise immunity, and enhances production efficiency. Precisely controlling the extrusion parameters ensures uniform thickness of the insulation and semi-conductive layers, improving cable stability.

[0050] Furthermore, the present invention incorporates a bending deformation test to more accurately assess the bending performance of the core wire. After applying a preset bending force, the force is maintained for a preset duration to ensure the core wire is fully stretched and deformed. Based on the initial length and the stretched length, the core wire's degree of deformation during the bending process and its ability to recover after the bending force is removed can be assessed. The resulting bending characteristic values ​​of the core wire can be used to comprehensively assess its bending performance, improving the accuracy of the test assessment.

[0051] Furthermore, the present invention determines a first particle size characteristic value based on the particle size distribution of a single product, effectively characterizing the particle size characteristics of the base PTFE powder. It also determines a second particle size characteristic value based on the mixed particle size distribution, reflecting the particle size characteristics of the carbon-doped PTFE mixture and assessing the uniformity and stability of the mixture. By comparing the first and second particle size characteristic values, a reasonable thickness distribution and target thickness ratio are determined, optimizing the structure of the insulating and semiconductive layers, improving the quality of the subsequent extruded product, and enhancing the stability of the cable.

[0052] Furthermore, the present invention determines a first comparison coefficient based on the comparison result between the initial first thickness and the target first thickness, which can characterize the degree of deviation between the initial first thickness and the target first thickness. A second comparison coefficient is determined based on the comparison result between the initial second thickness and the target second thickness, which can characterize the degree of deviation between the initial second thickness and the target second thickness. By combining the first and second comparison coefficients, the standard pre-pressing parameters are adjusted to determine the set pre-pressing parameters. This optimizes the pre-pressing process, ensures that the thickness variation trend during the pre-pressing process approaches the target thickness, and guarantees that the pre-pressed blank has better uniformity and strength. This further improves the stability and noise resistance of the cable.

[0053] Furthermore, the present invention can accurately simulate the thickness change trend of the insulating layer and the semi-conductive layer during the forming process by constructing a first thickness characterization curve and a second thickness characterization curve, thereby determining the first thickness characterization value and the second thickness characterization value, and adjusting the standard pushing parameters to obtain the set pushing parameters, which can optimize the pushing and extrusion molding process, improve the flexibility of pushing and extrusion molding, ensure the quality and stability of the finished cable, and thus further improve the noise resistance of the cable.

[0054] Furthermore, after obtaining the target sheath, the present invention determines a braiding angle based on the sheath's bending characteristic value, and then braids the sheath material around the target sheath at the braiding angle. This ensures the density and uniformity of the braided layer, thereby improving shielding and mechanical properties and optimizing the cable's flexibility. The outer protective sheath is prepared based on the maximum deformation characteristic value of the braided sheath, ensuring the reliability and durability of the cable during use and extending its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of the process of the integrated extrusion molding method of the low-noise coaxial cable according to an embodiment of the present invention;

[0056] Figure 2 This is a schematic structural diagram of a cross section of a low-noise coaxial cable according to an embodiment of the present invention;

[0057] Figure 3 Schematic diagram of the process of bending deformation test according to an embodiment of the present invention;

[0058] Figure 4 A logic decision diagram for determining whether a preset standard is met according to an embodiment of the present invention;

[0059] In the figure: 1. Core wire; 2. Insulation layer; 3. Semi-conductive layer; 4. Shielding layer; 5. Outer protective cover. DETAILED DESCRIPTION

[0060] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0061] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0062] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0063] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0064] See also Figure 1-Figure 4 As shown, Figure 1 Schematic diagram of the process of the integrated extrusion molding method of the low-noise coaxial cable according to an embodiment of the present invention; Figure 2 This is a schematic structural diagram of a cross section of a low-noise coaxial cable according to an embodiment of the present invention; in the figure: a core wire 1; an insulating layer 2; a semi-conductive layer 3; a shielding layer 4; and an outer protective sheath 5.

[0065] An embodiment of the present invention provides a method for integrated extrusion molding of a low-noise coaxial cable, comprising:

[0066] Step S1, performing a bending deformation test on the core wire 1 to obtain a core wire bending characteristic value of the core wire 1;

[0067] See also Figure 3 , which is a schematic diagram of the process of the bending deformation test according to an embodiment of the present invention; specifically, the process of the bending deformation test includes:

[0068] Step S11, fixing one end of the object to be measured and applying a preset bending force to the other end of the object to be measured, so that the object to be measured is bent around a bending mold core to a preset bending angle, wherein the core diameter of the bending mold core is determined according to the measured diameter of the object to be measured;

[0069] During implementation, a bending deformation test is performed on the core wire 1, and the target to be measured is the core wire sample. The actual implementer can set a preset bending force of 1 / 5 to 1 / 6 of the minimum bending force that causes the sample to break based on actual conditions or historical data. The preset bending angle can be 90° or 180°. Preferably, the core diameter of the bending mold core is 30 to 50 times the measured diameter of the target to be measured. When the core wire 1 is subjected to a bending deformation test, the core diameter of the bending mold core can be 30 to 50 times the diameter of the core wire 1.

[0070] Step S12, maintaining a preset time length, and measuring the stretched length of the measured object after removing the preset bending force;

[0071] In practice, the preset time length preferably ranges from 1 minute to 5 minutes. The stretched length is the total length of the measured object after the preset bending force is removed, and the initial length is the total length of the measured object before the preset bending force is applied.

[0072] Step S13: determining a bending characteristic value of the object to be measured based on the initial length of the object to be measured and the stretched length.

[0073] It is understood that the bending characteristic value of the measured object is the ratio of the difference between the stretched length and the initial length of the measured object to the initial length. When performing a bending deformation test on the core wire 1, the core wire bending characteristic value is the ratio of the difference between the stretched length and the initial length of the core wire sample to the initial length. Preferably, the initial length of the core wire sample ranges from 1m to 3m.

[0074] It is understandable that there is no specific limitation on the equipment and structure of the bending deformation test. For example, it can be achieved by a bending testing machine.

[0075] The present invention utilizes a bending deformation test to more accurately assess the bending performance of the core wire 1. After applying a preset bending force, the force is maintained for a preset duration to ensure that the core wire 1 is fully stretched and deformed. Based on the initial length and the stretched length, the degree of deformation of the core wire 1 during the bending process and its ability to recover after the bending force is removed can be assessed. The core wire bending characteristic values ​​thus determined can be used to comprehensively assess the bending performance of the core wire 1, improving the accuracy of the test assessment.

[0076] Step S2, mixing the conductive carbon powder with the basic PTFE powder based on a preset ratio to obtain a carbon-doped PTFE mixture, and obtaining a single product particle size distribution corresponding to the basic PTFE powder and a mixed particle size distribution corresponding to the carbon-doped PTFE mixture;

[0077] In implementation, a preset ratio can be set based on the ratio of conductive carbon powder to basic PTFE powder that has passed the qualification test in historical data. Preferably, the conductive carbon powder content is 5wt% to 15wt%, the conductive carbon powder can be acetylene black, and the particle size range is preferably 10nm to 100nm, and the basic PTFE powder is pure PTFE powder, and the particle size range is preferably 20μm to 50μm.

[0078] It is understood that the conductive carbon powder and the basic PTFE powder can be mixed by a high-speed mixer and ultrasonically dispersed to ensure that the conductive carbon powder is evenly dispersed in the basic PTFE powder.

[0079] It is understood that the equipment and method for measuring particle size distribution are not specifically limited. For example, the particle size distribution of the base PTFE powder alone and the mixed particle size distribution of the carbon-doped PTFE mixture can be measured using a laser particle size analyzer. The particle size distribution includes the percentage of particle sizes within each range.

[0080] Step S3, determining a target thickness ratio of the insulating layer 2 to the semiconductive layer 3 based on the core wire bending characteristic value, the single product particle size distribution, and the mixed particle size distribution, and determining an initial first thickness and an initial second thickness based on the target thickness ratio;

[0081] Specifically, in step S3, the process of determining the target thickness ratio includes:

[0082] Step S31, determining a first particle size characteristic value based on the particle size distribution of the single product;

[0083] In implementation, D10 (the particle size corresponding to when the cumulative distribution accounts for 10% in the basic PTFE powder) and D90 (the particle size corresponding to when the cumulative distribution accounts for 90% in the basic PTFE powder) can be determined based on the particle size distribution of the single product, and the ratio of D10 to D90 can be determined as the first particle size characteristic value.

[0084] Step S32, determining a second particle size characteristic value based on the mixed particle size distribution;

[0085] In implementation, H10 (the particle size corresponding to when the cumulative distribution in the carbon-doped PTFE mixture accounts for 10%) and H90 (the particle size corresponding to when the cumulative distribution in the carbon-doped PTFE mixture accounts for 90%) can be determined based on the particle size distribution of the single product, and the ratio of H10 to H90 can be determined as the second particle size characteristic value.

[0086] Step S33: determining the target thickness ratio based on the first particle size characteristic value and the second particle size characteristic value.

[0087] In implementation, the product of the first particle size characteristic value and the second particle size characteristic value is determined as the comprehensive particle size characteristic value, and the ratio of the comprehensive particle size characteristic value to the core wire bending characteristic value is determined as the target thickness ratio, which is the ratio of the thickness of the insulating layer 2 to the thickness of the semiconductor layer.

[0088] The present invention determines a first particle size characteristic value based on the particle size distribution of a single product, effectively characterizing the particle size characteristics of the base PTFE powder. It also determines a second particle size characteristic value based on the mixed particle size distribution, reflecting the particle size characteristics of the carbon-doped PTFE mixture and assessing the uniformity and stability of the mixture. By comparing the first and second particle size characteristic values, a reasonable thickness allocation and target thickness ratio are determined, optimizing the structure of the insulating layer 2 and the semiconductive layer 3, improving the quality of the subsequent extruded product, and enhancing the stability of the cable.

[0089] Specifically, in step S3, the process of determining the initial first thickness and the initial second thickness based on the target thickness ratio includes:

[0090] Step S34, determining an initial first thickness based on the target thickness ratio and the standard thickness;

[0091] Step S35 : determining an initial second thickness based on the target thickness ratio and the initial first thickness.

[0092] In implementation, the standard thickness is the total thickness of the mold filling area, that is, the standard thickness BH is the sum of the initial first thickness CYH and the initial second thickness CEH, then CYH=MB×BH, CEH=BH-CYH, where MB is the target thickness ratio.

[0093] Step S4, filling the insulating filling layer of the mold with basic PTFE powder based on the initial first thickness, and filling the semi-conductive filling layer of the mold with a carbon-doped PTFE mixture based on the initial second thickness, and controlling the mold to perform pre-pressing molding with set pre-pressing parameters to obtain a pre-pressed blank;

[0094] In implementation, the filling area of ​​the mold can be divided into an insulating filling layer and a semi-conductive filling layer by a stainless steel cylindrical partition. After the insulating filling layer of the mold is filled with basic PTFE powder based on the initial first thickness, and the semi-conductive filling layer of the mold is filled with a carbon-doped PTFE mixture based on the initial second thickness, the stainless steel cylindrical partition is gently pulled out to allow the basic PTFE powder to contact the carbon-doped PTFE mixture.

[0095] Specifically, in step S4, the set pre-compression parameter is determined based on the initial first thickness and the initial second thickness.

[0096] Specifically, the process of determining the set preload parameters includes:

[0097] Step S41, determining a first comparison coefficient based on a comparison result between the initial first thickness and the target first thickness;

[0098] Step S42, determining a second comparison coefficient based on a comparison result between the initial second thickness and the target second thickness;

[0099] Step S43: determining the set preloading parameters based on the first comparison coefficient, the second comparison coefficient, and standard preloading parameters; wherein the preloading parameters include but are not limited to preloading pressure and preloading duration.

[0100] In implementation, the target first thickness is the thickness of the insulating layer 2 after extrusion molding, and the target second thickness is the thickness of the semi-conductive layer 3 after extrusion molding. The ratio of the target first thickness to the initial first thickness is determined as the first comparison coefficient, and the ratio of the target second thickness to the initial second thickness is determined as the second comparison coefficient, and the average of the first comparison coefficient and the second comparison coefficient is determined as the comprehensive comparison coefficient.

[0101] It can be understood that the product of the comprehensive comparison coefficient and the standard preloading pressure is determined as the set preloading pressure, and the product of the comprehensive comparison coefficient and the standard preloading time is determined as the set preloading time.

[0102] It can be understood that the actual implementers can set the standard pre-compression pressure based on the actual situation or the pre-compression pressure that has passed the qualification test in the historical data, and the actual implementers can set the standard pre-compression time based on the actual situation or the pre-compression time that has passed the qualification test in the historical data. Preferably, the standard pre-compression pressure value range is set to 20MPa~30MPa, and the standard pre-compression time value range is set to 3min~10min.

[0103] The present invention determines a first comparison coefficient based on the comparison result between the initial first thickness and the target first thickness, which can characterize the degree of deviation between the initial first thickness and the target first thickness. It also determines a second comparison coefficient based on the comparison result between the initial second thickness and the target second thickness, which can characterize the degree of deviation between the initial second thickness and the target second thickness. By combining the first and second comparison coefficients, the standard pre-pressing parameters are adjusted to determine the set pre-pressing parameters. This optimizes the pre-pressing process, ensures that the thickness variation trend during the pre-pressing process approaches the target thickness, and ensures that the pre-pressed blank has better uniformity and strength. This further improves the stability and noise resistance of the cable.

[0104] Step S5, determining whether a preset standard is met based on the first intermediate thickness and the second intermediate thickness corresponding to the pre-pressed blank; if so, determining and setting extrusion parameters based on the first intermediate thickness and the second intermediate thickness;

[0105] See also Figure 4 As shown in FIG. , it is a logic determination diagram for determining whether a preset standard is met according to an embodiment of the present invention; specifically, in step S5, the process of determining whether the preset standard is met includes:

[0106] Step S51, determining a critical thickness ratio based on the intermediate first thickness and the intermediate second thickness;

[0107] Step S52 : determining whether the preset standard is met based on a comparison result between the key thickness ratio and the preset thickness ratio.

[0108] In implementation, the middle first thickness is the thickness of the pre-pressed blank after pre-pressing corresponding to the initial first thickness, and the middle second thickness is the thickness of the pre-pressed blank after pre-pressing corresponding to the initial second thickness.

[0109] It can be understood that the thickness comparison value is determined based on the critical thickness ratio and the preset thickness ratio (the thickness comparison value can be the difference between the critical thickness ratio and the preset thickness ratio), and whether the preset standard is met is determined based on the comparison result of the thickness comparison value and the preset comparison value. If the thickness comparison value is less than the preset comparison value, it is determined that the preset standard is met; if the thickness comparison value is greater than or equal to the preset comparison value, it is determined that the preset standard is not met.

[0110] It is understandable that the actual implementer can set the preset thickness ratio based on the actual situation or the average thickness ratio after pre-pressing that has passed the qualification test in historical data. Preferably, the preset comparison value is set in the range of 0.05 to 0.1.

[0111] Specifically, in step S5, the process of determining the setting pushing parameters includes:

[0112] Step S53, constructing a first thickness characterization curve based on the intermediate first thickness, the initial first thickness, and the target first thickness, and determining a first thickness characterization value based on the first thickness characterization curve;

[0113] Step S54, constructing a second thickness characterization curve based on the intermediate second thickness, the initial second thickness, and the target second thickness, and determining a second thickness characterization value based on the second thickness characterization curve;

[0114] Step S55, determining a comprehensive adjustment coefficient based on the first thickness characterizing value and the second thickness characterizing value;

[0115] Step S56: determining the set pushing parameters based on the comprehensive adjustment coefficient and the standard pushing parameters; wherein the pushing parameters include but are not limited to pushing temperature and pushing speed.

[0116] In implementation, a first thickness characterization curve is constructed by data fitting with the initial first thickness as the starting point, the target first thickness as the end point, and the intermediate first thickness as the intermediate point, and the slope at the intermediate first thickness is used as the first thickness characterization value. A second thickness characterization curve is constructed by data fitting with the initial second thickness as the starting point, the target second thickness as the end point, and the intermediate second thickness as the intermediate point, and the slope at the intermediate second thickness is used as the second thickness characterization value.

[0117] It can be understood that the ratio of the first thickness characterization value to the second thickness characterization value is determined as the comprehensive adjustment coefficient, the product of the comprehensive adjustment coefficient and the standard pushing temperature is determined as the set pushing temperature, and the product of the comprehensive adjustment coefficient and the standard pushing speed is determined as the set pushing speed.

[0118] It is understandable that the actual implementers can set the standard pushing temperature based on the actual situation or the pushing temperature that has passed the qualification test in the historical data, and the actual implementers can set the standard pushing speed based on the actual situation or the pushing speed that has passed the qualification test in the historical data. Preferably, the standard pushing temperature value range is set to 300℃~400℃, and the standard pushing speed value range is set to 10mm / min~30mm / min.

[0119] By constructing a first thickness characterization curve and a second thickness characterization curve, the present invention can accurately simulate the thickness change trend of the insulating layer 2 and the semi-conductive layer 3 during the molding process, thereby determining the first thickness characterization value and the second thickness characterization value, and adjusting the standard pushing parameters to obtain the set pushing parameters. It can optimize the pushing and extrusion molding process, improve the flexibility of pushing and extrusion molding, ensure the quality and stability of the finished cable, and thus further improve the noise resistance of the cable.

[0120] Step S6: Based on the set extrusion parameters, the pre-pressed blank and the core wire 1 are extruded as an integrated whole to obtain a target cladding body.

[0121] Specifically, after obtaining the target coating body, the method further includes:

[0122] Step S71, performing a bending deformation test on the target coating to obtain a coating bending characteristic value of the target coating;

[0123] Step S72 , determining a braiding angle based on the bending characteristic value of the coating, and braiding the coating material around the target coating at the braiding angle to obtain a braided coating; wherein the braided coating includes a shielding layer 4 and a target coating.

[0124] In implementation, the braiding angle is determined as the product of the bending characteristic value of the coating and the standard angle.

[0125] It is understandable that the actual implementer can set the standard angle based on the actual situation or the braiding angle that has passed the qualification test in the historical data. Preferably, the standard angle value range is set to 50° to 60°.

[0126] Step S73, obtaining the maximum deformation characteristic value of the braided covering body to determine the outer covering thickness;

[0127] Specifically, in step S73, the process of determining the outer protection thickness includes:

[0128] Step S731, marking a first point, a second point, and a midpoint between the first point and the second point on a preset length of the braided sheath;

[0129] Step S732, using the midpoint as a bending axis, bending the braided covering body with a set bending radius;

[0130] In practice, the set bending radius may be 5 to 10 times the diameter of the braided sheath.

[0131] Step S733, obtaining the maximum deformation area and the minimum deformation area within a preset length of the braided covering to determine the maximum deformation characteristic value;

[0132] In practice, the preset length is based on one end point of the braided covering as a starting point, and the preferred value range is set to 30 cm to 50 cm.

[0133] It is understandable that the maximum deformation area and the minimum deformation area can be determined by continuously acquiring images of the braided covering during the bending process, and the ratio of the minimum deformation area to the maximum deformation area can be determined as the maximum deformation characteristic value.

[0134] Step S734: determining the outer protection thickness based on the maximum deformation characteristic value and the diameter of the braided covering body.

[0135] In implementation, the product of the maximum deformation characteristic value and the diameter of the braided covering is determined as the outer covering thickness.

[0136] Step S74 , preparing an outer protective sheath 5 based on the outer protective sheath thickness, and wrapping the outer protective sheath 5 around the outer periphery of the braided sheath to obtain a low-noise coaxial cable.

[0137] After obtaining the target sheath, the present invention determines a braiding angle based on the sheath's bending characteristic value. The sheathing material is then braided and wrapped around the target sheath at the braiding angle, ensuring the density and uniformity of the braided layer, thereby improving shielding and mechanical properties and optimizing the cable's flexibility. The outer protective sheath is prepared based on the maximum deformation characteristic value of the braided sheath, ensuring the reliability and durability of the cable during use and extending its service life.

[0138] The present invention can evaluate the bending resistance of the core wire by performing a bending deformation test on the core wire, determine the core wire bending characteristic value of the core wire based on the test results, and accurately characterize the bending characteristics of the core wire. By mixing the conductive carbon powder with the basic PTFE powder according to a preset ratio and controlling the carbon powder dosage, the conductivity and mechanical properties of the carbon-doped PTFE mixture can be optimized. The target thickness ratio of the insulating layer to the semi-conductive layer is determined based on the core wire bending characteristic value, the particle size distribution of the single product, and the mixed particle size distribution. The thickness is reasonably allocated by comprehensively considering the core wire bending characteristics, the uniformity of the basic PTFE powder and the carbon-doped PTFE mixture, and the noise resistance of the cable during bending and use can be ensured. By determining the initial first thickness and the initial second thickness based on the target thickness ratio, filling the mold with the basic PTFE powder and the carbon-doped PTFE mixture, and controlling the mold to set pre-pressing parameters for pre-pressing, material waste can be reduced, the powder particles can be ensured to be tightly combined, and the strength and uniformity of the pre-pressed blank can be improved. Through pre-pressing, deformation and cracks that may occur in the subsequent extrusion molding process can be reduced, thereby improving product quality. By checking the thickness after pre-pressing to ensure the stability and uniformity of the blank and adjusting the extrusion parameters based on the pre-pressed thickness, molding efficiency and product quality can be improved. Extruding the pre-pressed blank and core wire in an integrated manner based on the set extrusion parameters eliminates delamination interfaces, improves the cable's stability and noise immunity, and enhances production efficiency. Precisely controlling the extrusion parameters ensures uniform thickness of the insulation and semi-conductive layers, improving cable stability.

[0139] Example 1:

[0140] This embodiment provides a low-noise coaxial cable prepared by the low-noise coaxial cable integrated extrusion molding method of the present invention. The conductive carbon powder content is 8 wt%, the pre-pressing pressure is set to 25 MPa, the pre-pressing time is set to 4 minutes, the extrusion temperature is set to 360°C, the extrusion speed is set to 20 mm / min, the core diameter is 1.0 mm, the insulation layer thickness is 0.55 mm, the semi-conductive layer thickness is 0.1 mm, the shielding layer thickness is 0.05 mm, the outer protective sheath thickness is 0.3 mm, and the outer diameter of the finished low-noise coaxial cable is 2.0 mm. The surface resistivity, noise voltage reduction rate (compared with the conventional method), and bending life test results (±90°, 10,000 times) are shown in Table 1.

[0141] Example 2:

[0142] This embodiment provides a low-noise coaxial cable prepared by the integrated extrusion molding method of the present invention. The conductive carbon powder content is 15 wt %, the pre-pressing pressure is set to 25 MPa, the pre-pressing time is set to 2 min, the extrusion temperature is set to 360° C., the extrusion speed is set to 15 mm / min, the core diameter is 1.0 mm, the insulation layer thickness is 0.35 mm, the semi-conductive layer thickness is 0.08 mm, the shielding layer thickness is 0.03 mm, the outer protective sheath thickness is 0.1 mm, and the finished low-noise coaxial cable has an outer diameter of 1.56 mm. The surface resistivity, noise voltage reduction rate (compared with the conventional method), and bending life test results (±90°, 10,000 times) are shown in Table 1.

[0143] Example 3:

[0144] This embodiment provides a low-noise coaxial cable prepared by a conventional method. Each layer is formed by coating with the core wire having a diameter of 1.0 mm, an insulating layer thickness of 0.55 mm, a semi-conductive layer thickness of 0.1 mm, a shielding layer thickness of 0.05 mm, and an outer protective sheath thickness of 0.3 mm. The finished low-noise coaxial cable has an outer diameter of 2.0 mm. The surface resistivity, noise voltage reduction rate, and bending life test results (±90°, 10,000 times) are shown in Table 1.

[0145] Table 1 Comparison of surface resistivity, noise voltage reduction rate, and bending life test of various embodiments

[0146]

[0147] As can be seen from Table 1, the surface resistance performance of the low-noise coaxial cable prepared by the low-noise coaxial cable integrated extrusion molding method of the present invention is significantly better than that of the low-noise coaxial cable prepared by the conventional method. After multiple bending, the low-noise coaxial cable of the present invention does not crack and the noise voltage reduction rate is significantly improved.

[0148] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A low-noise coaxial cable integrated extrusion molding method, characterized in that: include: Performing a bending deformation test on the core wire to obtain a core wire bending characteristic value of the core wire; Mixing the conductive carbon powder with the basic PTFE powder based on a preset ratio to obtain a carbon-doped PTFE mixture, and obtaining a single product particle size distribution corresponding to the basic PTFE powder and a mixed particle size distribution corresponding to the carbon-doped PTFE mixture; determining a target thickness ratio of the insulating layer to the semiconductive layer based on the core wire bending characteristic value, the single product particle size distribution, and the mixed particle size distribution, and determining an initial first thickness and an initial second thickness based on the target thickness ratio; Filling the insulating filling layer of the mold with basic PTFE powder based on the initial first thickness, and filling the semi-conductive filling layer of the mold with a carbon-doped PTFE mixture based on the initial second thickness, and controlling the mold to perform pre-pressing molding with set pre-pressing parameters to obtain a pre-pressed blank; Determining whether a preset standard is met based on a first intermediate thickness and a second intermediate thickness corresponding to the pre-pressed blank, and if so, determining and setting a pushing parameter based on the first intermediate thickness and the second intermediate thickness; Based on the set extrusion parameters, the pre-pressed blank and the core wire are integrally extruded to obtain a target cladding body; The process of determining the target thickness ratio includes: Determining a first particle size characteristic value based on the single product particle size distribution; determining a second particle size characteristic value based on the mixed particle size distribution; determining the target thickness ratio based on the core wire bending characteristic value, the first particle size characteristic value, and the second particle size characteristic value; The process of determining the initial first thickness and the initial second thickness based on the target thickness ratio includes: determining an initial first thickness based on the target thickness ratio and a standard thickness; determining an initial second thickness based on the target thickness ratio and the initial first thickness; Among them, the low noise coaxial cable includes a core wire, an insulation layer and a semi-conductive layer; The intermediate first thickness is the thickness after pre-pressing corresponding to the initial first thickness of the pre-pressing blank, and the intermediate second thickness is the thickness after pre-pressing corresponding to the initial second thickness of the pre-pressing blank.

2. The low-noise coaxial cable integrated extrusion molding method according to claim 1, characterized in that: The bending deformation test process includes: Fixing one end of the object to be measured and applying a preset bending force to the other end of the object to be measured so that the object to be measured is bent around a bending mold core to a preset bending angle, wherein the core diameter of the bending mold core is determined according to the measured diameter of the object to be measured; Maintaining a preset time, and measuring the stretched length of the object to be measured after removing the preset bending force; The bending characteristic value of the object to be measured is determined based on the initial length of the object to be measured and the stretched length.

3. The low-noise coaxial cable integrated extrusion molding method according to claim 2, characterized in that: The set pre-compression parameter is determined based on the initial first thickness and the initial second thickness.

4. The low-noise coaxial cable integrated extrusion molding method according to claim 3, characterized in that: The process of determining the set preload parameters includes: determining a first comparison coefficient based on a comparison result of the initial first thickness and the target first thickness; determining a second comparison coefficient based on a comparison result of the initial second thickness and the target second thickness; The set preload parameter is determined based on the first comparison coefficient, the second comparison coefficient, and a standard preload parameter.

5. The low-noise coaxial cable integrated extrusion molding method according to claim 4, characterized in that: The process for determining whether the pre-set criteria are met includes: determining a critical thickness ratio based on the intermediate first thickness and the intermediate second thickness; Based on the comparison result of the critical thickness ratio and the preset thickness ratio, it is determined whether it meets the preset standard.

6. The low-noise coaxial cable integrated extrusion molding method according to claim 5, characterized in that: The process of determining the setting pushing parameters includes: constructing a first thickness characterization curve based on the intermediate first thickness, the initial first thickness, and the target first thickness, and determining a first thickness characterization value based on the first thickness characterization curve; constructing a second thickness characterization curve based on the intermediate second thickness, the initial second thickness, and the target second thickness, and determining a second thickness characterization value based on the second thickness characterization curve; determining a comprehensive adjustment coefficient based on the first thickness characterizing value and the second thickness characterizing value; The set pushing parameter is determined based on the comprehensive adjustment coefficient and the standard pushing parameter.

7. The integrated extrusion molding method for low-noise coaxial cables according to claim 6, characterized in that: After obtaining the target coating body, the method further comprises: Performing a bending deformation test on the target coating to obtain a coating bending characteristic value of the target coating; Determining a braiding angle based on the bending characteristic value of the coating, and braiding the coating material around the target coating at the braiding angle to obtain a braided coating; Obtaining the maximum deformation characteristic value of the braided sheath to determine the outer sheath thickness; An outer protective sheath is prepared based on the outer protective sheath thickness, and the outer protective sheath is coated on the periphery of the braided coating body to obtain a low-noise coaxial cable.

8. The low-noise coaxial cable integrated extrusion molding method according to claim 7, characterized in that: The process of determining the outer protective thickness includes: Marking a first point, a second point, and a midpoint between the first point and the second point on a predetermined length of the braided sheath; Taking the middle point as the bending axis, the braided covering body is bent with a set bending radius; Obtaining a maximum deformation area and a minimum deformation area within a preset length of the braided sheath to determine the maximum deformation characteristic value; The outer protection thickness is determined based on the maximum deformation characteristic value and the diameter of the braided covering.

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