A heat-resistant radio frequency coaxial cable

Abstract

The present invention discloses a heat-resistant radio frequency coaxial cable, which relates to the field of radio frequency coaxial cables. The cable comprises an inner conductor, an insulating layer, a shielding layer and an outer protective sleeve. The insulating layer is coated on the outer end face of the inner conductor. The insulating layer is composed of an inner skin layer, a foaming layer and an outer skin layer. The shielding layer is arranged on the outer end face of the insulating layer. The shielding layer comprises a graphene inner shielding layer located on the inner side. The outer end face of the graphene inner shielding layer is coated and connected with a ceramic fiber layer. The present invention uses a high-pressure foaming layer of carbon dioxide for insulation, which effectively ensures that the insulation performance of the cable's insulation layer is higher, and the return loss is also greatly improved. The shielding layer adopts a metal outer shielding layer and a graphene inner shielding layer, which greatly enhances the shielding effect of the cable. At the same time, a ceramic fiber layer is arranged in the middle, and the ceramic fiber layer is filled with a flame retardant for flame retardancy and heat insulation.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency coaxial cables, in particular to a heat-resistant radio frequency coaxial cable. Background Art

[0002] With the continuous development of our science and technology, electronic communications and networks are developing more rapidly, and radio frequency cables connected inside or between electronic devices are particularly important. The heat resistance of existing radio frequency coaxial cables is difficult to meet the development of today's electronic communications, and the insulation effect of their insulation layer is poor. In addition, the shielding layer mostly uses a single metal shield, which not only has a low shielding effect, but also the metal shielding layer is mostly woven, which makes it less stable and prone to loosening, greatly reducing its service life. Summary of the Invention

[0003] The object of the present invention is to provide a heat-resistant radio frequency coaxial cable to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: A heat-resistant radio frequency coaxial cable, comprising an inner conductor, an insulating layer, a shielding layer and an outer protective sheath, wherein the insulating layer is covered and arranged on the outer end surface of the inner conductor, the insulating layer is composed of an inner skin layer, a foaming layer and an outer skin layer, the shielding layer is arranged on the outer end surface of the insulating layer, and the outer protective sheath is fixedly connected to the outer end surface of the shielding layer, the shielding layer comprises an inner graphene shielding layer located on the inner side, the outer end surface of the graphene inner shielding layer is covered and connected with a ceramic fiber layer, the outer end surface of the ceramic fiber layer is wrapped and connected with a metal outer shielding layer, the outer protective sheath comprises an EP rubber layer located on the inner side, the inner end surface of the EP rubber layer is provided with protrusions equidistantly distributed at four directions along the length direction of the cable, the outer end surface of the EP rubber layer is wrapped and covered with an elastic protective layer, the outer end surface of the elastic protective layer is covered with an alumina fiber layer, and the outer end surface of the alumina fiber layer is covered with a polyvinyl chloride coating layer.

[0005] Preferably, the inner end surface of the ceramic fiber layer is provided with openings at equal intervals, and each opening is filled with a flame retardant.

[0006] Preferably, the outer end face of the metal outer shielding layer is provided with long grooves at equal intervals, and the metal outer shielding layer is wound and connected to the outer end face of the metal outer shielding layer at a forty-five-degree angle, so that the last layer of the long grooves distributed on the outer side of the metal outer shielding layer is distributed in an inclined shape, and the protrusions are embedded in the corresponding long grooves, so that an embedment is formed between the protrusions and the long grooves, further improving the connection strength between the shielding layer and the outer protective cover, and at the same time effectively preventing the metal outer shielding layer from loosening during subsequent use of the cable, and some protrusions that are not embedded in the long grooves form compression with the outer end face of the metal outer shielding layer, and can also provide a certain buffer support.

[0007] Preferably, the elastic protective layer is a mesh structure formed by the intersection of two horizontal and longitudinal round rubber threads.

[0008] Preferably, the method for preparing the insulating layer comprises the following steps:

[0009] Step 1: Preparation of the inner layer of the insulation layer: low-density polyethylene, resin solution glue and epoxy resin are mixed and heated, then added to the extruder screw and evenly extruded on the surface of the conductor inside the tube, and then air-cooled to 45℃~60℃ on the convex part;

[0010] Step 2: Preparation of the insulating foam layer: High-density polyethylene, low-density polyethylene, and azodicarbonamide nucleating agent are mixed and added to the extruder for heating and melting. At the same time, high-pressure carbon dioxide is introduced for thorough mixing and foaming. The mixture is then extruded and coated onto the inner conductor covered with the inner layer after cooling in step 1.

[0011] Step 3: Prepare the outer layer of the insulating layer. Add polyamide hot melt adhesive into the extruder, heat it to 185 degrees, and extrude it onto the inner conductor covered with the foam layer in step 2. Finally, mix oil and water, cool it, and air dry it.

[0012] Preferably, in the step 1, the ratio of low-density polyethylene, resin solution glue and epoxy resin is 5:2:1, the heating temperature is controlled at about 145° C. to 185° C., and the extrusion thickness is 0.1 mm.

[0013] Preferably, in the step 2, the raw material ratio of high-density polyethylene, low-density polyethylene and azodicarbonamide nucleating agent is 74:25:1, and they are heated and melted to 140°C to 150°C and kept warm. The extrusion outlet temperature is controlled to deviate from the raw material melting temperature by no more than 5°C.

[0014] Preferably, the pressure of the carbon dioxide introduced in step 2 is controlled at 20-35 MPa, the temperature is 195° C., and the carbon dioxide is high-purity carbon dioxide.

[0015] Preferably, in step three, the oil-water mixed cooling is to first cool the oil at a temperature of 30° C. to 40° C., and then add it to water at normal room temperature for water cooling.

[0016] In summary, the beneficial effects of the present invention are:

[0017] The present invention uses a high-pressure foaming layer of carbon dioxide for insulation, which effectively ensures that the insulation performance of the cable's insulation layer is higher, and the return loss is also greatly improved. The shielding layer adopts a metal outer shielding layer and a graphene inner shielding layer, which greatly enhances the shielding effect of the cable. At the same time, a ceramic fiber layer is provided in the middle, and the ceramic fiber layer is filled with a flame retardant for flame retardant and heat insulation. The shielding layer and the outer protective sleeve are contacted and connected with the metal outer shielding layer through the EP rubber layer. The protrusion is embedded in the corresponding elongated groove, so that the protrusion and the elongated groove are embedded, further improving the connection strength between the shielding layer and the outer protective sleeve. At the same time, it can also effectively prevent the metal outer shielding layer from loosening during subsequent use of the cable. Some protrusions that are not embedded in the elongated groove form compression with the outer end face of the metal outer shielding layer, and can also provide a certain buffer support. The alumina fiber layer and the polyvinyl chloride coating layer provided on the outside further improve its thermal insulation and wear resistance, greatly improving the service life of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of the overall structure of a heat-resistant radio frequency coaxial cable of the present invention;

[0020] Figure 2 This is a schematic cross-sectional structure diagram of a shielding layer 3 in a heat-resistant radio frequency coaxial cable of the present invention;

[0021] Figure 3 This is a schematic cross-sectional structure diagram of the inner and outer protective sheaths 4 of a heat-resistant radio frequency coaxial cable according to the present invention;

[0022] Figure 4 For the present invention Figure 2 Schematic diagram of the partial structure of the ceramic fiber layer 32 of the middle component;

[0023] Figure 5 For the present invention Figure 3Schematic diagram of the partially expanded structure of the elastic protective layer 42 of the middle component;

[0024] Figure 6 This is a framework diagram of the process for preparing the insulating layer 2 in a heat-resistant radio frequency coaxial cable of the present invention.

[0025] The symbols in the accompanying drawings are described as follows: 1. inner conductor; 2. insulation layer; 3. shielding layer; 4. outer protective sleeve; 31. metal outer shielding layer; 32. ceramic fiber layer; 33. flame retardant; 34. graphene inner shielding layer; 35. long groove; 41. EP300 rubber layer; 42. elastic protective layer; 43. alumina fiber layer; 44. polyvinyl chloride coating layer; 45. protrusion. DETAILED DESCRIPTION

[0026] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0027] Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0028] The following combination Figure 1-6 The present invention is described in detail. For the convenience of description, the directions mentioned below are defined as follows: the up, down, left, right, front and back directions mentioned below are the same as Figure 1 The front, back, left, right, up and down directions of the view are consistent. Figure 1 It is a front view of the device of the present invention, Figure 1 The directions shown are consistent with the front, back, left, right, up and down directions of the device of the present invention when viewed from the front.

[0029] See also Figure 1-6, an embodiment provided by the present invention: a heat-resistant radio frequency coaxial cable, comprising an inner conductor 1, an insulating layer 2, a shielding layer 3 and an outer protective sheath 4, wherein the insulating layer 2 is coated on the outer end surface of the inner conductor 1, the insulating layer 2 is composed of an inner skin layer, a foaming layer and an outer skin layer, the shielding layer 3 is arranged on the outer end surface of the insulating layer 2, the outer protective sheath 4 is fixedly connected to the outer end surface of the shielding layer 3, the shielding layer 3 includes a graphene inner shielding layer 34 located on the inner side, and the outer end surface of the graphene inner shielding layer 34 is coated with a ceramic fiber layer 3 2. The outer end surface of the ceramic fiber layer 32 is wrapped and connected with the metal outer shielding layer 31. The outer protective sleeve 4 includes an EP300 rubber layer 41 located on the inner side. The inner end surface of the EP300 rubber layer 41 is provided with protrusions 45 equidistantly distributed at four positions along the length direction of the cable. The outer end surface of the EP300 rubber layer 41 is wrapped and covered with an elastic protective layer 42. The outer end surface of the elastic protective layer 42 is covered with an alumina fiber layer 43. The outer end surface of the alumina fiber layer 43 is covered with a polyvinyl chloride coating layer 44.

[0030] In addition, in one embodiment, openings 36 are evenly distributed on the inner end surface of the ceramic fiber layer 32 , and each of the openings 36 is filled with a flame retardant 33 .

[0031] In addition, in one embodiment, the outer end face of the metal outer shielding layer 31 is provided with long grooves 35 at equal intervals, and the metal outer shielding layer 31 is connected to the outer end face of the metal outer shielding layer 31 at a forty-five-degree angle, so that the last layer of the long grooves 35 distributed on the outer side of the metal outer shielding layer 31 is distributed in an inclined shape, and the protrusions 45 are embedded in the corresponding long grooves 35, so that an embedding is formed between the protrusions 45 and the long grooves 35, further improving the connection strength between the shielding layer 3 and the outer protective cover 4, and at the same time, it can effectively prevent the metal outer shielding layer 31 from loosening during subsequent use of the cable, and some protrusions 45 that are not embedded in the long grooves 35 form compression with the outer end face of the metal outer shielding layer 31, and can also provide a certain buffer support.

[0032] In addition, in one embodiment, the elastic protective layer 42 is a mesh structure formed by crossing two round rubber threads in the transverse direction and the longitudinal direction.

[0033] In addition, in one embodiment, the method for preparing the insulating layer 2 includes the following steps:

[0034] Step 1: Preparation of the inner layer of the insulation layer: low-density polyethylene, resin solution glue and epoxy resin are mixed and heated, then added to the extruder screw and evenly extruded on the surface of the conductor inside the tube, and then air-cooled to 45℃~60℃ on the convex part;

[0035] Step 2: Preparation of the insulating foam layer: High-density polyethylene, low-density polyethylene, and azodicarbonamide nucleating agent are mixed and added to the extruder for heating and melting. At the same time, high-pressure carbon dioxide is introduced for thorough mixing and foaming. The mixture is then extruded and coated onto the inner conductor covered with the inner layer after cooling in step 1.

[0036] Step 3: Prepare the outer layer of the insulating layer. Add polyamide hot melt adhesive into the extruder, heat it to 185 degrees, and extrude it onto the inner conductor covered with the foam layer in step 2. Finally, mix oil and water, cool it, and air dry it.

[0037] In addition, in one embodiment, the ratio of low-density polyethylene, resin solution glue and epoxy resin in step 1 is 5:2:1, the heating temperature is controlled at about 145° C. to 185° C., and the extrusion thickness is 0.1 mm.

[0038] In addition, in one embodiment, the raw material ratio of high-density polyethylene, low-density polyethylene, and azodicarbonamide nucleating agent in step 2 is 74:25:1, and they are heated and melted to 140°C to 150°C, and kept warm. The extrusion outlet temperature is controlled to deviate from the melting temperature of the raw materials by no more than 5°C.

[0039] In addition, in one embodiment, the pressure of the carbon dioxide introduced in step 2 is controlled at 20-35 MPa, the temperature is 195° C., and the carbon dioxide is high-purity carbon dioxide.

[0040] In addition, in one embodiment, the oil-water mixed cooling in step three is to first cool the oil at a temperature of 30° C. to 40° C., and then add it to water at normal room temperature for water cooling.

[0041] The present invention uses a foaming layer foamed with carbon dioxide to insulate the outer layer of the inner conductor. The high-pressure foaming of carbon dioxide can make the polyethylene foaming degree higher, thereby making the insulation performance of the insulation layer of the cable higher, and the return loss is also greatly improved. The shielding layer arranged on the outside of the insulation layer is composed of a mixture of a graphene inner shielding layer 34 and a metal outer shielding layer 31. At the same time, a ceramic fiber layer 32 is arranged in the middle, and a flame retardant 33 is filled in 36 of the ceramic fiber layer 32 for flame retardancy and heat insulation. The shielding layer 3 and the outer protective sheath 4 are contacted and connected with the metal outer shielding layer 31 through the EP300 rubber layer 41, and the protrusion 45 is embedded in the corresponding long groove 35, so that the protrusion The protrusions 45 that are not embedded in the long grooves 35 are compressed with the outer end faces of the metal outer shielding layer 31, and can also provide certain buffer support. The elastic protective layer 42 on the outside of the EP300 rubber layer 41 can further improve the impact resistance and elastic recovery ability of the cable. The alumina fiber layer 43 and the polyvinyl chloride coating layer 44 arranged on the outside further improve its heat insulation and wear resistance, thereby greatly improving the service life of the cable.

[0042] The above description is merely a specific embodiment of the invention, but the scope of protection of the invention is not limited thereto. Any changes or substitutions that are not conceived through creative effort should be included within the scope of protection of the invention. Therefore, the scope of protection of the invention should be based on the scope of protection defined in the claims.

Claims

1. A heat-resistant radio frequency coaxial cable, comprising an inner conductor (1), an insulating layer (2), a shielding layer (3) and an outer protective sheath (4), characterized in that: The insulating layer (2) is coated and arranged on the outer end face of the inner conductor (1), the insulating layer (2) is composed of an inner skin layer, a foaming layer and an outer skin layer, the shielding layer (3) is arranged on the outer end face of the insulating layer (2), the outer protective sleeve (4) is fixedly connected to the outer end face of the shielding layer (3), the shielding layer (3) includes a graphene inner shielding layer (34) located on the inner side, the outer end face of the graphene inner shielding layer (34) is coated and connected with a ceramic fiber layer (32), the outer end face of the ceramic fiber layer (32) is wound and connected with a metal outer shielding layer (31), the outer protective sleeve (4) includes an EP300 rubber layer (41) located on the inner side, the The inner end surface of the EP300 rubber layer (41) is provided with raised portions (45) at equal intervals along the length direction of the cable at four positions, the outer end surface of the EP300 rubber layer (41) is wrapped with an elastic protective layer (42), the outer end surface of the elastic protective layer (42) is covered with an aluminum oxide fiber layer (43), the outer end surface of the aluminum oxide fiber layer (43) is covered with a polyvinyl chloride coating layer (44), the inner end surface of the ceramic fiber layer (32) is provided with openings (36) at equal intervals, and each of the openings (36) is filled with a flame retardant (33), and the preparation method of the insulating layer (2) comprises the following steps: Step 1: Preparation of the inner layer of the insulation layer: low-density polyethylene, resin solution glue and epoxy resin are mixed and heated, then added to the extruder screw and evenly extruded on the surface of the conductor inside the tube, and then air-cooled; Step 2: Preparation of the insulating foam layer: High-density polyethylene, low-density polyethylene, and azodicarbonamide nucleating agent are mixed and added to an extruder for heating and melting. At the same time, high-pressure carbon dioxide is introduced for thorough mixing and foaming. The mixture is then extruded and coated onto the inner conductor covered with the inner layer after cooling in step 1; Step 3: Prepare the outer layer of the insulating layer. Add polyamide hot melt adhesive into the extruder, heat it to 185 degrees, and extrude it onto the inner conductor covered with the foam layer in step 2. Finally, mix oil and water, cool it, and air dry it.

2. The heat-resistant radio frequency coaxial cable according to claim 1, characterized in that: In the step 1, the ratio of low-density polyethylene, resin solution glue and epoxy resin is 5:2:1, the heating temperature is controlled at 145° C. to 185° C., and the extrusion thickness is 0.1 mm.

3. The heat-resistant radio frequency coaxial cable according to claim 1, characterized in that: In the step 2, the raw material ratio of high-density polyethylene, low-density polyethylene, and azodicarbonamide nucleating agent is 74:25:1, and they are heated and melted to 140° C. to 150° C. and kept warm. The extrusion outlet temperature is controlled to be within 5° C. of the raw material melting temperature.

4. The heat-resistant radio frequency coaxial cable according to claim 1, characterized in that: The pressure of the carbon dioxide introduced in step 2 is controlled at 20-35 MPa, the temperature is 195° C., and the carbon dioxide is high-purity carbon dioxide.

5. The heat-resistant radio frequency coaxial cable according to claim 1, characterized in that: In the step 3, the oil-water mixed cooling is to first cool the oil at a temperature of 30° C. to 40° C., and then add it to water at normal room temperature for water cooling.

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