A negative pressure and circulation drying composite device and a manufacturing process for rat and ant-proof cables

Abstract

The present invention belongs to the technical field of cable manufacturing, and discloses a negative pressure and circulating drying composite device and a process for manufacturing rat- and ant-proof cables. The negative pressure and circulating drying composite device includes a hollow negative pressure device, an annular dryer, an air pipe, and a vortex air pump. One end of the hollow negative pressure device is fixedly connected to the input end of the machine head, and the annular dryer is sleeved on the other end of the hollow negative pressure device. A first air inlet and a first air outlet are provided. The first air outlet can form an annular air outlet. The air pipe includes an air inlet pipe and an air outlet pipe. The two ends of the air inlet pipe are respectively connected to the interior of the hollow negative pressure device and the second air inlet of the vortex air pump. The two ends of the air outlet pipe are respectively connected to the first air inlet and the second air outlet of the vortex air pump. The vortex air pump can extract the high-temperature gas inside the machine head through the hollow negative pressure device and transport it to the first air inlet. The present invention improves the negative pressure level of the machine head and the drying treatment effect of the surface of the incoming semi-finished product, reduces quality accidents, and thereby improves operating efficiency and yield.

Description

Technical Field

[0001] The present invention relates to the technical field of cable manufacturing, in particular to a negative pressure and circulation drying composite device and a process for manufacturing a rat and ant-proof cable. Background Art

[0002] In the traction power supply system of urban rail transit, the power supply cables of traction substations generally use rat-proof and ant-proof cables, which are used as feeders from the traction substation to the contact network and return lines from the running rails to the traction substation. In the process of preparing such cables, especially in the extrusion process, centrifugal fans and simple hand-made hollow cardboard are often used to generate a certain negative pressure during extrusion, so that the extruded material can better adhere to the outside of the cable semi-finished product. However, the negative pressure level generated by this operation is low, and the adhesion effect is general. In addition, the process temperature during the extrusion process is very high. Therefore, the dryness of the surface of the cable semi-finished product is required to be high. If there are water stains or high humidity on the surface of the cable semi-finished product, the residual water will be heated by high temperature during the extrusion process and easily vaporize, causing blistering, leading to product quality defects and reduced yield. Therefore, how to increase the negative pressure level and keep the surface of the cable semi-finished product dry in an efficient and energy-saving manner is an urgent problem that needs to be solved in the current cable production. Summary of the Invention

[0003] The purpose of the present invention is to provide a negative pressure and circulating drying composite device and a rat-ant-proof cable manufacturing process, so as to improve the negative pressure level, keep the surface of the semi-finished cable dry, realize the recycling of gas in the cable manufacturing process, reduce quality problems, improve the yield and operating efficiency, reduce energy consumption, and be more environmentally friendly.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A negative pressure and circulating drying composite device, comprising:

[0006] A hollow negative pressure device, one end of which is fixedly connected to the input end of the handpiece, and a semi-finished cable can pass through the hollow negative pressure device and enter the handpiece;

[0007] An annular dryer is sleeved on the other end of the hollow negative pressure device and is provided with a first air inlet and a first air outlet. The first air inlet is connected to the first air outlet, and the first air outlet can form an annular air outlet.

[0008] an air pipe, comprising an air inlet pipe and an air outlet pipe, wherein one end of the air inlet pipe is connected to the interior of the hollow negative pressure device, and one end of the air outlet pipe is connected to the first air inlet;

[0009] The vortex air pump is provided with a second air inlet and a second air outlet. The second air inlet is connected to the other end of the air inlet pipe, and the second air outlet is connected to the other end of the air outlet pipe. The vortex air pump can extract the internal gas of the head through the hollow negative pressure device and transport it to the first air inlet through the air inlet pipe and the air outlet pipe.

[0010] Optionally, the annular dryer is provided with a plurality of nozzles, the plurality of nozzles are evenly arranged along the circumference of the annular dryer, and the first air outlet is provided on the nozzles.

[0011] As an option, the axis of the nozzle intersects with the axis of the annular dryer.

[0012] Optionally, the hollow negative pressure device includes a hollow negative pressure body and a bolt, and the hollow negative pressure body is fixed to the machine head by the bolt.

[0013] The manufacturing process of rat and ant proof cable includes:

[0014] S1. Prepare conductor;

[0015] S2, extruded insulation layer;

[0016] S3, wrapping water blocking layer;

[0017] S4, extruded fire insulation layer;

[0018] S5, wrapping anti-rat layer;

[0019] S6, extruded outer sheath;

[0020] S7, extruding a thin-walled anti-termite layer, and completing the manufacturing process through the negative pressure and circulating drying composite device and the die head;

[0021] S8. Inspection and packaging of finished products.

[0022] Optionally, the S7 includes:

[0023] S7.1. Turn on the vortex air pump;

[0024] S7.2. After the outer sheath is extruded, the semi-finished cable product is passed through an annular dryer, a hollow negative pressure device and a machine head in sequence, and a thin-walled anti-termite layer is extruded under negative pressure.

[0025] Optionally, the S7 further includes:

[0026] S7.2.1. The annular dryer uses a nozzle to blow air evenly around the cable semi-finished product after the outer sheath is extruded and dried;

[0027] S7.2.2. The vortex air pump draws high-temperature air from the interior of the handpiece through the air inlet pipe from the hollow negative pressure device, generating negative pressure inside the handpiece, causing the thin-walled anti-termite layer to adhere to the outside of the outer protective layer;

[0028] S7.2.3. The vortex air pump delivers the extracted gas to the first air inlet of the annular dryer through the air outlet pipe.

[0029] Optionally, the rodent-proof layer in S5 is made of copper-zinc alloy material.

[0030] Optionally, the thin-walled anti-termite layer in S7 is made of nylon material.

[0031] As an option, the insulating layer in S2 is made of ethylene propylene rubber insulating material.

[0032] Beneficial effects of the present invention:

[0033] By combining the vortex air pump, the hollow negative pressure device, and the air inlet pipe, the gas inside the die can be extracted, creating a negative pressure environment inside the die. This significantly increases the negative pressure level during the extrusion process, reduces the gap between the extruded material and the outside of the cable semi-finished product, and improves its coating tightness. Secondly, by combining the vortex air pump, the air outlet pipe, and the annular dryer, the gas can be output from the air outlet pipe to the first air inlet of the annular dryer, forming an annular air outlet at the first air outlet, which blows away from the direction of travel of the cable semi-finished product. This ensures that the annular air outlet fully dries the surface of the cable semi-finished product before it enters the die for extrusion, avoiding bubbling during subsequent operations and improving product quality and yield. At the same time, due to the high temperature inside the die, the temperature of the gas extracted by the vortex air pump is also high, resulting in a better drying effect of the annular air outlet and the ability to preheat the cable semi-finished product to ensure high-quality extrusion.

[0034] Furthermore, during the overall cable production process, after the semi-finished cable with an extruded outer sheath is annularly dried, negative pressure is applied to adhere the thin-walled anti-termite layer to the outer sheath. This ensures that the outer sheath is clean and free of foreign matter before the thin-walled anti-termite layer is extruded, facilitating adhesion. Under the action of negative pressure, the thin-walled anti-termite layer and the outer sheath are tightly adhered together, ensuring stable coating on the outer side of the cable and extending its service life. Using a combined negative pressure and circulating drying device can speed up cable production, reduce quality incidents, improve operational efficiency and yield, reduce energy consumption, and achieve more environmentally friendly gas recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the machine head and the negative pressure and circulation drying composite device in the manufacturing process of the rat and ant proof cable according to an embodiment of the present invention;

[0036] Figure 2 yes Figure 1 Schematic diagram of the middle ring dryer in direction A;

[0037] Figure 3 1 is a schematic structural diagram of a rat- and ant-proof cable according to an embodiment of the present invention;

[0038] Figure 4 It is a schematic flow chart of the manufacturing process of the rat-proof and ant-proof cable according to an embodiment of the present invention.

[0039] In the picture:

[0040] 100-conductor; 200-machine head; 10-insulating layer; 20-water-blocking layer; 30-fireproof layer; 40-rodent-proof layer; 50-outer protective layer; 60-thin-walled anti-termite layer; 70-negative pressure and circulating drying composite device; 71-hollow negative pressure device; 711-bolt; 72-annular dryer; 721-nozzle; 73-air pipe; 731-inlet pipe; 732-outlet pipe; 74-vortex air pump. DETAILED DESCRIPTION

[0041] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0042] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, mechanical or electrical connections, direct or indirect connections through an intermediate medium, and internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0043] In the description of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0044] During the extrusion process of cable preparation, a negative pressure device is often used to better adhere the extruded material to the outside of the cable semi-finished product. However, the negative pressure level generated by this operation is low, and the adhesion effect is general. In addition, during the extrusion process, the process temperature is very high. Therefore, the dryness requirement for the surface of the cable semi-finished product is relatively high. If there is residual water stains or high humidity on the surface of the cable semi-finished product, the residual water will be heated by high temperature during the extrusion process and easily vaporize, causing blistering, leading to product quality defects and reduced yield.

[0045] The technical solution of this embodiment will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0046] like Figure 1-Figure 2 As shown, this embodiment provides a negative pressure and circulation drying composite device 70 , including a hollow negative pressure device 71 , an annular dryer 72 , an air pipe 73 and a vortex air pump 74 . Optionally, one end of the hollow negative pressure device 71 is fixedly connected to the input end of the machine head 200, and the cable semi-finished product can pass through the hollow negative pressure device 71 to enter the machine head 200. The annular dryer 72 is sleeved on the other end of the hollow negative pressure device 71 and is provided with a first air inlet and a first air outlet. The first air inlet is connected to the first air outlet, and the first air outlet can form an annular air outlet. The air pipe 73 includes an air inlet pipe 731 and an air outlet pipe 732. One end of the air inlet pipe 731 is connected to the inside of the hollow negative pressure device 71, and one end of the air outlet pipe 732 is connected to the first air inlet. The vortex air pump 74 is provided with a second air inlet and a second air outlet. The second air inlet is connected to the other end of the air inlet pipe 731, and the second air outlet is connected to the other end of the air outlet pipe 732. The vortex air pump 74 can extract the internal gas of the machine head 200 through the hollow negative pressure device 71 and transport it to the first air inlet through the air inlet pipe 731 and the air outlet pipe 732.

[0047] Specifically, in this embodiment, by using the vortex air pump 74, the hollow negative pressure device 71 and the air inlet pipe 731 in conjunction with each other, the gas inside the head 200 can be extracted, and a negative pressure environment can be achieved inside the head 200, which greatly improves the negative pressure level in the extrusion process, and reduces the gap between the extruded material and the outside of the cable semi-finished product, thereby improving its coating tightness. Secondly, by using the vortex air pump 74, the air outlet pipe 732 and the annular dryer 72 in conjunction with each other, the gas can be output from the air outlet pipe 732 to the first air inlet of the annular dryer 72, and an annular air outlet is formed at the first air outlet, blowing away from the direction of travel of the cable semi-finished product, thereby ensuring that the surface of the cable semi-finished product is fully dried by the annular air outlet before it enters the head 200 for extrusion, thereby avoiding bubbling during subsequent operations, thereby improving product quality and yield rate. At the same time, since the internal temperature of the head 200 is relatively high, the temperature of the gas extracted by the vortex air pump 74 is also relatively high, so the drying effect of the annular air outlet is better, and the cable semi-finished product can be preheated to ensure high-quality completion of the extrusion operation.

[0048] The overall structure of the negative pressure and circulation drying combined device 70 in this embodiment will be described below.

[0049] like Figure 1 As shown, the negative pressure and circulating drying combined device 70 in this embodiment includes a hollow negative pressure device 71, an annular dryer 72, an air pipe 73, and a vortex air pump 74. The hollow negative pressure device 71 includes a bolt 711, the air pipe 73 includes an air inlet pipe 731 and an air outlet pipe 732, and the annular dryer 72 is provided with a plurality of nozzles 721.

[0050] Specifically, the hollow negative pressure device 71 includes a hollow negative pressure body and a bolt 711, and the hollow negative pressure body is fixed to the head 200 by the bolt 711. Optionally, two bolts 711 are provided in this embodiment. In other embodiments, the number of bolts 711 and the connection method between the hollow negative pressure body and the head 200 can be determined as needed, and will not be described in detail here. When the hollow negative pressure device 71 is fixed to the input end of the head 200, the semi-finished cable can be passed through the inner hole of the hollow negative pressure body and enter the head 200 for subsequent extrusion operation.

[0051] Optionally, an annular dryer 72 is sleeved on the other end of the hollow negative pressure device 71 away from the head 200, and is provided with a first air inlet and a first air outlet, which are interconnected to ensure airflow in the annular dryer 72. Furthermore, the first air outlet can form an annular air outlet to dry the semi-finished cable product in its circumferential direction before it enters the hollow negative pressure device 71.

[0052] Optionally, the vortex air pump 74 is provided with a second air inlet and a second air outlet. In this embodiment, the two ends of the air inlet pipe 731 are respectively connected to the second air inlet of the vortex air pump 74 and the interior of the hollow negative pressure device 71, and the two ends of the air outlet pipe 732 are respectively connected to the second air outlet of the vortex air pump 74 and the first air inlet of the annular dryer 72. In this way, the vortex air pump 74 is respectively connected to the hollow negative pressure device 71 and the annular dryer 72, thereby enabling gas circulation.

[0053] Optionally, in this embodiment, the annular dryer 72 is provided as an annular structure, which is sleeved on one end of the input port of the hollow negative pressure device 71. The annular dryer 72, the hollow negative pressure device 71 and the input port of the head 200 are coaxially arranged, so as to facilitate the smooth entry of the semi-finished cable into the head 200. Furthermore, a plurality of nozzles 721 are provided on the annular dryer 72, such as Figure 2As shown, multiple nozzles 721 are evenly arranged along the circumference of the annular dryer 72. Furthermore, the nozzles 721 are configured as cylindrical structures, and the axes of the multiple nozzles 721 intersect with the axis of the annular dryer 72. In this embodiment, the axes of the multiple nozzles 721 intersect at a single point, and this point of intersection is on the axis of the annular dryer 72, thereby forming an annular air outlet, which uniformly circumferentially dries the semi-finished cable product.

[0054] Optionally, the nozzle 721 is provided with a first air outlet along its axial direction and is arranged toward the cable. A first air inlet is provided on the annular dryer 72. The air outlet pipe 732 is connected to the first air inlet, and the first air outlet is connected to the first air inlet, thereby forming a gas passage, and the gas entering the first air inlet of the annular dryer 72 is discharged from the first air outlet, thereby achieving comprehensive drying of the outside of the cable semi-finished product and improving the operation quality and efficiency.

[0055] This embodiment also provides a process for manufacturing a rat- and ant-proof cable, comprising:

[0056] S1. preparing a conductor 100;

[0057] S2, extruded insulation layer 10;

[0058] S3, wrapping the water-blocking layer 20;

[0059] S4, extruded fire insulation layer 30;

[0060] S5, wrapping the rat-proof layer 40;

[0061] S6, extruded outer protective layer 50;

[0062] S7, extruding a thin-walled anti-termite layer 60, and completing the manufacturing process through the negative pressure and circulating drying composite device 70 and the die head 200;

[0063] S8. Inspection and packaging of finished products.

[0064] During the overall cable production process, after the surface of the semi-finished cable with the extruded outer sheath 50 is annularly dried, negative pressure is applied to adhere the thin-walled anti-termite layer 60 to the outer surface of the outer sheath 50. This ensures that the outer surface of the outer sheath 50 is clean and free of foreign matter before the thin-walled anti-termite layer 60 is extruded, facilitating adhesion. Under the action of negative pressure, the thin-walled anti-termite layer 60 and the outer sheath 50 are tightly adhered together, ensuring stable coating on the outer surface of the cable and extending its service life. The use of the combined negative pressure and circulating drying device 70 accelerates cable production, reduces quality incidents, improves operational efficiency and yield, reduces energy consumption, and achieves environmentally friendly gas recycling.

[0065] For example, the rat-proof and ant-proof cable in this embodiment is provided with a conductor 100, an insulating layer 10, a water-blocking layer 20, a fire-insulating layer 30, a rat-proof layer 40, an outer sheath 50 and a thin-walled ant-proof layer 60 from the inside to the outside, and the rat-proof layer 40 is made of a copper-zinc alloy material, and the thin-walled ant-proof layer 60 is made of a nylon material.

[0066] In the prior art, chemical reagents are often added to the cable sheath to prevent rats and ants from damaging the cable. However, most of these chemical reagents contain ingredients such as capsaicin, which are not only highly irritating but may even be toxic. When workers are handling and installing cables, their skin can easily develop allergies or even ulcers after coming into contact with these reagents. Furthermore, the pungent smell can harm the workers' respiratory tract. Therefore, in this embodiment, the rat-proof layer 40 is made of a copper-zinc alloy, which has excellent wear resistance and a hard and smooth surface that is difficult for rats to chew. The thin-walled ant-proof layer 60 is made of nylon, which can effectively prevent termite infestation and formic acid corrosion. This reduces the use of chemical reagents, achieves rat-proofing of the cable through physical protection, reduces the occurrence of allergies and other discomfort during the handling and installation of cables, protects the personal safety of workers, and improves work efficiency.

[0067] Specifically, if Figure 3 As shown, in this embodiment, the insulation layer 10 insulates the conductor 100 from other structures, preventing safety hazards such as electrical leakage. The water-blocking layer 20 and the fire-insulating layer 30 provide the conductor 100 with excellent waterproof and fireproof properties. The rodent-proof layer 40 and the thin-walled termite-proof layer 60 protect the cable from damage by rats and termites, extending its service life. The outer sheath 50 tightly encases the cable core, enhancing overall sheath strength.

[0068] For example, conductor 100 utilizes Class 5 copper conductors as specified in the GB / T3956-2008 standard to achieve the overall cable's conductivity. Insulation layer 10 is made of EPDM insulation material, meeting the requirements of the GB / T28429-2012 standard, and insulates the outer circumference of conductor 100 to prevent safety hazards such as leakage through circumferentially connected components.

[0069] Optionally, the water-blocking layer 20 comprises a water-blocking tape, which provides water-blocking protection for the conductor 100 and achieves radial water resistance when the cable is in a humid environment or underwater. Water-blocking tape is a common feature in the art and will not be described in detail here. Furthermore, the fire-insulating layer 30 is made of a polyolefin material containing a high-efficiency flame retardant, which improves the overall flame retardancy of the cable.

[0070] Exemplarily, the rat-proof layer 40 is made of a copper-zinc alloy with a zinc content within the range of 35%-37%. Specifically, in this embodiment, the zinc content of the rat-proof layer 40 is controlled within the range of 35.5%-36.8%, thereby improving the mechanical properties of the rat-proof layer 40 and enhancing the cable's wear resistance. The copper-zinc alloy material's high resilience and smooth surface make the rat-proof layer 40 effectively resistant to rats, effectively protecting the cable from rats.

[0071] Optionally, the outer sheath 50 is also made of polyolefin material, which not only improves the overall waterproof and fireproof performance of the cable, but also can tightly wrap the cable core as a whole, thereby improving the overall connection strength. For example, the thin-walled anti-termite layer 60 is made of nylon material, and the thickness is set within the range of 0.2-0.3mm. Specifically, nylon 12 material can be selected. Nylon 12 is a nylon material with a hard texture. In this embodiment, the thickness of the thin-walled anti-termite layer 60 is an average of 0.25mm, which is very thin, more economical, and has better comprehensive performance. The provision of the thin-walled anti-termite layer 60 can effectively prevent the cable from being eaten by termites and corroded by formic acid, thereby enhancing the acid and pest resistance of the cable, effectively avoiding termite infestation in the cable trench of the traction substation, and extending the service life of the cable.

[0072] Specifically, in this embodiment, the insulating layer 10 is wrapped around the outside of the conductor 100, the water-blocking layer 20 is wrapped around the outside of the insulating layer 10, the fire-insulating layer 30 is wrapped around the outside of the water-blocking layer 20, the rat-proof layer 40 is arranged on the outside of the fire-insulating layer 30 and the inside of the outer protective layer 50, and the thin-walled anti-ant layer 60 is wrapped around the outside of the outer protective layer 50.

[0073] Further, if Figure 4 As shown, in step S1 of this embodiment, the conductor 100 is formed by drawing and annealing single filaments, then bundling and re-twisting them to achieve the cable's conductive properties. Drawing, annealing, bundling, and re-twisting are conventional in the art. Furthermore, in step S2, the EPDM insulation material of the insulation layer 10 is wrapped around the outside of the conductor 100 using an extrusion device. Optionally, in step S3, a water-blocking tape is wrapped around the outside of the insulation layer 10 using a wrapping device, and a fire-insulating layer 30 is extruded around the outside of the water-blocking layer 20. Optionally, in this embodiment, the copper-zinc alloy structure of the rat-proof layer 40 is wrapped around the outside of the fire-insulating layer 30 to prevent rats from gnawing on it, while also protecting the insulation layer 10 from electrical leakage. Furthermore, an outer sheath 50 is wrapped around the outside of the rat-proof layer 40 and placed at the input port of the machine head 200, ready for application of the thin-walled anti-termite layer 60. The extrusion and wrapping procedures described above are conventional in the art and will not be further described here.

[0074] Optionally, step S7 includes:

[0075] S7.1. Turn on the vortex air pump 74;

[0076] S7.2. After the outer sheath 50 is extruded, the semi-finished cable product is sequentially passed through the annular dryer 72, the hollow negative pressure device 71 and the machine head 200, and a thin-walled anti-termite layer 60 is extruded under negative pressure.

[0077] Specifically, the semi-finished cable product is passed through the annular dryer 72 for drying before the machine head 200, and since the extrusion process of the nylon material of the thin-walled anti-ant layer 60 needs to maintain the operating temperature at about 250°C, the surface dryness of the incoming semi-finished cable product is required to be relatively high. If there are water stains or high humidity on the outside of the outer sheath 50, gasification will occur during the extrusion of the thin-walled anti-ant layer 60. The expansion of the gas will affect the extrusion, resulting in the presence of blistering quality defects on the surface of the thin-walled anti-ant layer 60, which not only reduces the yield of the cable, but also prolongs the overall production time due to rework production and reduces operating efficiency. Therefore, the above-mentioned quality defects can be avoided by pre-drying the outside of the outer sheath 50 in the annular dryer 72.

[0078] Optionally, step S7.2 includes:

[0079] S7.2.1. The annular dryer 72 uses the nozzle 721 to blow air evenly around the circumference of the semi-finished cable with the outer sheath 50;

[0080] S7.2.2. The vortex air pump 74 extracts high-temperature gas from the inside of the handpiece 200 from the hollow negative pressure device 71 through the air inlet pipe 731, generating negative pressure inside the handpiece 200, so that the thin-walled anti-ant layer 60 adheres to the outside of the outer protective layer 50.

[0081] After drying in an annular dryer 72, the semi-finished cable, wrapped with an outer sheath 50, is placed inside the die head 200. Specifically, a thin-walled nylon anti-termite layer 60 is formed inside the die head 200, and the thin-walled anti-termite layer 60 is extruded onto the semi-finished cable inside the die head 200. For example, in this embodiment, to prevent excessive interfacial space between the thin-walled nylon anti-termite layer 60 and the outer sheath 50, a hollow negative pressure device 71 is employed to improve adhesion between the thin-walled anti-termite layer 60 and the outer sheath 50. Specifically, the vortex air pump 74 draws air from the inside of the hollow negative pressure device 71 through the air inlet pipe 731, placing the interior of the device in a negative pressure state, so that the negative pressure at the output port of the machine head 200 is -340 mbar, which is more than three times that of a traditional negative pressure device (a centrifugal fan and a hollow cardboard setting, with a negative pressure of -110 mbar). This greatly reduces the interface gap between the thin-walled anti-ant layer 60 and the outer protective layer 50, improves the wrapping tightness of the thin-walled anti-ant layer 60, and improves the protective life and effect of the thin-walled anti-ant layer 60.

[0082] Optionally, step S7.2 further includes:

[0083] S7.2.3. The vortex air pump 74 delivers the extracted gas to the first air inlet of the annular dryer 72 through the air outlet pipe 732.

[0084] Specifically, the vortex air pump 74 transports gas extracted from the interior of the die head 200 via the outlet pipe 732 to the first air inlet of the annular dryer 72. The gas is then ejected from the first outlet to the exterior of the outer sheath 50 via the nozzle 721, completing the annular drying process. For example, during the operation of the die head 200, the temperature inside the die head 200 is relatively high, and a significant amount of heat is generated during the extrusion of the thin-walled anti-termite layer 60. Through the connection between the air inlet pipe 731, the vortex air pump 74, the outlet pipe 732, and the annular dryer 72, the nozzle 721 sprays heated gas onto the surface of the semi-finished cable with the extruded outer sheath 50, thereby improving drying efficiency and preheating the entire semi-finished cable, facilitating its close bonding with the thin-walled anti-termite layer 60 upon entry into the die head 200. This ensures that the extrusion of the thin-walled anti-termite layer 60 meets the design quality requirements. Furthermore, the recycling of heat and gas reduces energy consumption, resulting in a highly efficient and environmentally friendly drying and negative pressure operation.

[0085] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A negative pressure and circulation drying composite device, characterized in that: include: A hollow negative pressure device (71), one end of which is fixedly connected to the input end of the handpiece (200), and a semi-finished cable can pass through the hollow negative pressure device (71) and enter the handpiece (200); an annular dryer (72), sleeved on the other end of the hollow negative pressure device (71), provided with a first air inlet and a first air outlet, wherein the first air inlet is connected to the first air outlet, and the first air outlet can form an annular air outlet; An air pipe (73), comprising an air inlet pipe (731) and an air outlet pipe (732), wherein one end of the air inlet pipe (731) is connected to the interior of the hollow negative pressure device (71), and one end of the air outlet pipe (732) is connected to the first air inlet; A vortex air pump (74) is provided with a second air inlet and a second air outlet, wherein the second air inlet is connected to the other end of the air inlet pipe (731), and the second air outlet is connected to the other end of the air outlet pipe (732). The vortex air pump (74) can extract the internal gas of the handpiece (200) through the hollow negative pressure device (71) and transport it to the first air inlet through the air inlet pipe (731) and the air outlet pipe (732); The annular dryer (72) is provided with a plurality of nozzles (721), the plurality of nozzles (721) are evenly arranged along the circumference of the annular dryer (72), and the first air outlet is provided on the nozzles (721); The axis of the nozzle (721) intersects with the axis of the annular dryer (72).

2. The negative pressure and circulation drying combined device according to claim 1, characterized in that: The hollow negative pressure device (71) comprises a hollow negative pressure body and a bolt (711), and the hollow negative pressure body is fixed to the machine head (200) via the bolt (711).

3. The manufacturing process of rat-proof and ant-proof cable is characterized in that: include S1. preparing a conductor (100); S2, extruded insulation layer (10); S3, wrapping a water-blocking layer (20); S4, extruded fire insulation layer (30); S5, wrapping the rat-proof layer (40); S6, extruding an outer protective layer (50); S7, extruding a thin-walled anti-termite layer (60), manufactured by the negative pressure and circulating drying composite device (70) according to any one of claims 1-2 and the die head (200); S8. Inspection and packaging of finished products.

4. The process for manufacturing rat-proof and ant-proof cables according to claim 3, characterized in that: The S7 includes: S7.

1. Turn on the vortex air pump (74); S7.

2. After the outer sheath (50) is extruded, the semi-finished cable product is sequentially passed through an annular dryer (72), a hollow negative pressure device (71) and a machine head (200), and a thin-walled anti-termite layer (60) is extruded under negative pressure.

5. The manufacturing process of the rat-proof and ant-proof cable according to claim 4, characterized in that: The S7.2 includes: S7.2.

1. The annular dryer (72) blows air uniformly around the semi-finished cable product after the outer sheath (50) is extruded through the nozzle (721) to dry the semi-finished cable product; S7.2.2, the vortex air pump (74) extracts high-temperature gas from the interior of the handpiece (200) from the hollow negative pressure device (71) through the air inlet pipe (731), generating negative pressure inside the handpiece (200), so that the thin-walled anti-termite layer (60) is attached to the outside of the outer protective layer (50); S7.2.

3. The vortex air pump (74) delivers the extracted gas to the first air inlet of the annular dryer (72) through the air outlet pipe (732).

6. The manufacturing process of the rat-proof and ant-proof cable according to claim 3, characterized in that: The rat-proof layer (40) in S5 is made of copper-zinc alloy material.

7. The process for manufacturing rat- and ant-proof cables according to claim 3, characterized in that: The thin-walled anti-termite layer (60) in S7 is made of nylon material.

8. The process for manufacturing rat- and ant-proof cables according to claim 3, characterized in that: The insulating layer (10) in S2 is made of ethylene propylene rubber insulating material.

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