An extrusion apparatus for cable insulation

Abstract

The present application relates to the technical field of cable manufacturing, in particular to an extrusion molding equipment for cable insulation sheath, which comprises an extrusion device including an extrusion head and a rotating assembly. By uniformly arranging multiple convex surfaces on the outer wall of the extrusion head in the circumferential direction, the radial distribution of the molten material in the flow channel is adjusted, and the molten material is guided to supplement the inter-strand gap of the multi-strand twisted cable. At the same time, the extrusion head is driven to rotate by the rotating assembly, so that the convex surface can adapt to the cable outer surface profile in real time. Therefore, the uniform thickness and smooth surface of the insulation layer are ensured, and the phenomenon of excessive collection or uneven distribution of materials to the gap is avoided, which not only eliminates the electrical hazards in the excessively thin area, but also reduces the material waste in the excessively thick area, thereby improving the insulation performance of the cable and the material utilization rate.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, and in particular to an extrusion molding equipment for cable insulation sheaths. Background Technology

[0002] Cross-linked polyethylene insulated power cables are high-performance power cables that are formed by cross-linking polyethylene molecular chains to create a three-dimensional network structure through chemical or physical methods. They have excellent heat resistance, mechanical strength, and electrical properties, and are widely used in medium and high voltage power transmission and distribution systems.

[0003] Cable insulation extrusion molding equipment can process recycled cross-linked polyethylene (XLPE) plastic waste into insulation material through specialized processes, achieving resource recycling while ensuring product performance and significantly reducing raw material consumption and solid waste emissions during production. When producing XLPE insulated power cables, cable insulation extrusion molding equipment typically includes a pay-off device, a conductor preheater, an extruder, a die head, a dry cross-linking system or an irradiation cross-linking system, a cooling system, a traction machine, and a take-up machine. During production, the pay-off device releases copper or aluminum conductors, which are then straightened and preheated before entering the extruder. The extruder mixes and plasticizes the XLPE, uniformly extruding it onto the conductor surface through the die head to form an insulation layer. Subsequently, the cable enters the dry cross-linking system or the irradiation cross-linking system. In the dry cross-linking system, the insulation layer undergoes chemical cross-linking within a high-pressure, high-temperature vulcanization pipe, forming a three-dimensional network structure; if an irradiation cross-linking system is used, physical cross-linking is achieved through a high-energy electron beam. The cross-linked insulation layer is then rapidly shaped and cured by the cooling system to ensure its thermosetting properties. The traction machine maintains a constant speed, and finally the winding machine neatly winds up the finished cable.

[0004] However, when processing cross-linked polyethylene (XLPE) insulated power cables with multi-stranded conductors using existing cable insulation extrusion molding equipment, the initial thickness of the molten XLPE material output from the extrusion die is uniform. However, the surface of the multi-stranded conductors has uneven inter-strand gaps, which actually require more material to fill. The mismatch between the uniform melt distribution and the uneven contour of the conductor surface causes the material to naturally converge towards the gap areas during flow. This can result in irregular depressions or protrusions on the surface of the extruded insulation layer before it enters the cross-linking process. This not only affects the cable's appearance but also damages the radial uniformity of the XLPE insulation layer. During the subsequent high-temperature, high-pressure cross-linking process, this initial thickness unevenness may be further solidified or exacerbated, ultimately leading to distortion of the local electric field distribution in the insulation layer. This significantly and adversely affects the cable's long-term dielectric strength, partial discharge resistance, and service life. Summary of the Invention

[0005] Therefore, it is necessary to provide a cable insulation extrusion molding device to address the problem that the initial thickness of the melt cross-linked polyethylene material is not uniform in current cable insulation extrusion molding equipment, resulting in irregular shapes on the surface of the insulation sheath.

[0006] The above objectives are achieved through the following technical solutions:

[0007] An extrusion molding apparatus for cable insulation sheathing includes an extrusion device comprising an extrusion shell, an extrusion head, and a rotating assembly. The extrusion shell has a through hole penetrating both axial end faces and a feed inlet. The extrusion head is coaxially rotatably connected to the inner wall of the extrusion shell, and a flow channel for molten material to pass through is formed between the extrusion head and the extrusion shell, the flow channel communicating with the feed inlet. A central channel for the cable to pass through is provided inside the extrusion head, and a plurality of convex surfaces are uniformly arranged circumferentially on the outer wall of the extrusion head, the plurality of convex surfaces being used to adjust the radial distribution of the molten material within the flow channel. The rotating assembly is used to drive the extrusion head to rotate so that the plurality of convex surfaces adapt to the outer surface contour of the cable.

[0008] Furthermore, the rotating assembly includes multiple guide units arranged axially in the central channel, which are used to straighten and limit the cable.

[0009] Furthermore, the extrusion device also includes a conveying pipe, the outer wall of which is coaxially fixedly connected to the extrusion housing, and the end of the conveying pipe extends into the extrusion housing; the extrusion head is rotatably connected to the end of the conveying pipe, and the central channel passes through the conveying pipe and the extrusion head.

[0010] Each of the guiding units includes a rotating ring and multiple guide wheels. The rotating ring is coaxially rotatably connected to the inner wall of the delivery pipe. The multiple guide wheels are evenly distributed circumferentially on the inner wall of the rotating ring and are rotatably connected to the inner wall of the rotating ring. The outer wall of each guide wheel is adapted to the outer surface contour of the cable. The guide wheels are used to straighten the cable when it passes through. When the cable passes through the central channel, the friction between the cable and the guide wheels can drive the rotating ring to rotate.

[0011] Furthermore, the rotating ring closest to the extrusion head is fixedly connected to the extrusion head. When the cable passes through the central channel, the cable can drive the rotating ring to rotate, thereby causing the extrusion head to rotate synchronously.

[0012] Furthermore, the guiding unit also includes multiple locking structures, which are disposed between adjacent rotating rings. The locking structures are used to lock the relative angular positions of adjacent rotating rings according to the twist pitch of the cable.

[0013] Furthermore, the locking structure includes a transmission rod, one end of which is fixedly connected to the end face of one of the rotating rings; the other end of the transmission rod is rotatably provided with an active pawl, and a first elastic element is provided between the transmission rod and the active pawl, the first elastic element being used to keep the active pawl tending towards the engagement direction; the other end face of the rotating ring is coaxially provided with a pawl groove, and the rotating ring is rotatably provided with a plurality of driven pawls in the pawl groove, the plurality of driven pawls being evenly distributed circumferentially in the pawl groove; a second elastic element is provided between the rotating ring and one of the driven pawls, each of the second elastic elements being used to keep one of the driven pawls tending towards the locked position.

[0014] The drive rod of one of the rotating rings can engage in the pawl groove of the adjacent rotating ring, the driving pawl and the driven pawl being used to enable the two adjacent rotating rings to rotate relative to each other in only a single circumference.

[0015] Furthermore, it also includes a cleaning device for adsorbing and cleaning the surface of the cable as it passes through the central channel.

[0016] Furthermore, the cleaning device includes a negative pressure source and an adsorption channel, the adsorption channel being connected to the negative pressure source, and the adsorption end of the adsorption channel being connected to the central channel.

[0017] Furthermore, the guide wheel has multiple through-holes for adsorption, and the outer wall of the rotating ring has an adsorption groove coaxially connected to the adsorption channel; the rotating ring also has an internal channel connecting the adsorption holes and the adsorption groove.

[0018] The plurality of guide wheels on one of the rotating rings are configured as convex wheels, the contours of which are adapted to the gaps between adjacent wires in the cable. The convex wheels are used to spread the adjacent wires apart when straightening the cable so that the suction holes can suck up impurities in the gaps between the wires.

[0019] Furthermore, the inner wall of the conveying pipe is provided with an annular guide groove, and the outer wall of the extrusion head is provided with a limiting slider that slides radially. A third elastic element is provided between the limiting slider and the extrusion head. The elastic force of the third elastic element always causes the limiting slider to extend out of the extrusion head and embed into the guide groove.

[0020] The beneficial effects of this invention are:

[0021] This invention provides an extrusion molding apparatus for cable insulation sheathing, comprising an extrusion device including an extrusion head and a rotating assembly. By uniformly arranging multiple convex surfaces circumferentially on the outer wall of the extrusion head, during the insulation sheathing process, after the molten material enters the flow channel, the convex surfaces apply a directional thrust to the flowing molten material, targeting the inter-strand gaps on the surface of the multi-stranded cable. This guides the molten material to precisely fill the gap areas, avoiding excessive accumulation at the gaps. Simultaneously, the rotating assembly drives the extrusion head to rotate around its own axis, with the rotation state adapted to the cable conveying rhythm. This allows the multiple convex surfaces on the outer wall of the extrusion head to dynamically adjust their positions in real time, following the contour of the cable's outer surface. The convex surfaces can promptly act on the molten material in the corresponding areas, ensuring that the molten material always uniformly covers the cable's outer surface, eliminating irregular shapes such as depressions and protrusions on the surface after insulation layer molding, and ensuring consistent insulation layer thickness. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of an extrusion molding equipment for cable insulation sheath provided in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 The front view of the structure shown;

[0024] Figure 3 This is a schematic diagram of the hot melt tube and extrusion device in an extrusion molding equipment for cable insulation sheath provided in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the extrusion device in an extrusion molding equipment for cable insulation sheath provided in an embodiment of the present invention;

[0026] Figure 5 for Figure 4 The front view of the structure shown;

[0027] Figure 6 for Figure 5 A cross-sectional view along the AA direction;

[0028] Figure 7 This is a schematic diagram of the structure of the extrusion head and the conveying pipe in the extrusion device provided in an embodiment of the present invention;

[0029] Figure 8 for Figure 7 The front view of the structure shown;

[0030] Figure 9 for Figure 8 Cross-sectional view along the BB direction;

[0031] Figure 10 for Figure 9 A magnified view of a section at point C;

[0032] Figure 11 This is a schematic diagram of the rotating ring in the extrusion device provided in an embodiment of the present invention;

[0033] Figure 12 for Figure 11 Side view of the structure shown;

[0034] Figure 13 for Figure 12 A cross-sectional view along the DD direction;

[0035] Figure 14 for Figure 12 A cross-sectional view along the EE direction;

[0036] Figure 15 This is an exploded view of the rotating ring structure in the extrusion device provided in an embodiment of the present invention;

[0037] Figure 16 This is a schematic diagram of the convex wheel in the extrusion device provided in an embodiment of the present invention;

[0038] Figure 17 This is a schematic diagram of the concave wheel in the extrusion device provided in an embodiment of the present invention.

[0039] in:

[0040] 110. Base; 120. Drive motor; 121. Transmission chain; 130. Hot melt pipe; 131. Hopper; 132. Heating ring; 140. Feeding shell;

[0041] 210. Extrusion shell; 211. Feed inlet; 212. Adjusting ring; 213. Adjusting sleeve; 214. Adjusting bolt; 215. Fixing plate; 216. Fixing bolt; 220. Extrusion head; 221. Limiting slider; 222. Third spring; 230. Conveying pipe; 240. Rotating ring; 241. Pawl groove; 242. Driven pawl; 243. Internal channel; 244. Adsorption tank; 250. Guide wheel; 251. Convex wheel; 252. Concave wheel; 253. Adsorption hole; 260. Transmission rod; 261. Active pawl. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] The following reference Figures 1 to 17 This invention describes an extrusion molding apparatus for cable insulation sheath provided by an embodiment of the present invention.

[0046] An extrusion molding device for cable insulation sheath provided in this embodiment of the invention includes a feeding device, a wire feeding device (not shown in the figure), and an extrusion device.

[0047] The feeding device includes a base 110, a drive motor 120, a heat-melting tube 130, and a feeding housing 140. The base 110 is a frame structure placed on the ground or other supporting surface. The base 110 provides a stable mounting foundation for other components of the feeding device, ensuring the overall structural stability of the device. The drive motor 120 is fixedly mounted on the base 110 and provides power for material conveying. A ring-shaped transmission chain 121 is connected to the output end of the drive motor 120, which stably transmits the power of the drive motor 120. The heat-melting tube 130 is a cylindrical tubular structure, with its input end connected to the transmission chain 121. The heat-melting tube 130 is fixedly mounted above the base 110 and is used to heat and melt the raw material for cable insulation. The molten material flows out from the output end of the heat-melting tube 130. A hopper 131 is fixedly installed on the hot melt tube 130, and the hopper 131 is connected to the interior of the hot melt tube 130. The hopper 131 is used to convey the raw material to be melted into the hot melt tube 130. Multiple heating rings 132 are coaxially fixedly installed on the outside of the hot melt tube 130. The heating rings 132 are used to provide continuous and uniform heat to the hot melt tube 130 to ensure that the raw material inside the hot melt tube 130 reaches a molten state. A feeding shell 140 is sleeved on the outside of the hot melt tube 130 and fixedly connected to the base 110. The feeding shell 140 is used to provide a working environment isolated from the external environment for the hot melt tube 130 to prevent the heat of the hot melt tube 130 from dissipating rapidly.

[0048] The wire feeding device includes a wire feeding frame, a wire feeding reel, guide wheels, a tension adjustment mechanism, and a cable guide tube. The wire feeding frame is a frame structure, directly fixed to the ground or other supporting surface, providing a mounting base for other components of the wire feeding device. The wire feeding reel is rotatably connected to the wire feeding frame and is used to wind and support the cable to be processed. The guide wheels are mounted on the wire feeding frame and are used to change the direction of the cable and perform initial straightening. The tension adjustment mechanism includes an adjusting wheel and a spring; by changing the position of the adjusting wheel and spring, the tension of the cable is adjusted to ensure a stable wire feeding process. The cable guide tube is fixedly installed at the end of the wire feeding frame and has a smooth interior; the cable guide tube is used to precisely guide the cable to the extrusion unit.

[0049] The extrusion device includes a fixed support (not shown in the figure), an extrusion housing 210, an extrusion head 220, and a delivery pipe 230.

[0050] The fixed bracket is a frame structure that is directly fixed to the ground or other supporting surface, and is used to provide an installation base for other components of the extrusion unit.

[0051] The extrusion shell 210 is a cylindrical shell structure, fixedly connected to a fixed support. The extrusion shell 210 has a circular through-hole penetrating both axial ends. An inlet 211 is provided on the extrusion shell 210, fixedly connected to the output end of the hot melt tube 130, used to transport the molten material inside the hot melt tube 130 to the interior of the extrusion shell 210. An adjusting ring 212 and an adjusting sleeve 213 are coaxially fixed to one end of the extrusion shell 210. The adjusting ring 212 is sleeved on the outer wall of the adjusting sleeve 213, and the inner wall of the adjusting sleeve 213 is an inner conical surface, used to guide the flow of molten material. The adjusting ring 212 and the adjusting sleeve 213 are fixedly connected by multiple adjusting bolts 214 evenly distributed circumferentially. Rotating the adjusting bolts 214 adjusts the relative position between the adjusting ring 212 and the adjusting sleeve 213. The other end of the extruded housing 210 is coaxially fixedly connected to a fixing plate 215. The fixing plate 215 is coaxially fixedly connected to one end of the cable guide tube from which the cable is led out, and the cable guide tube passes through the fixing plate 215. The fixing plate 215 and the extruded housing 210 are fixedly connected by multiple fixing bolts 216.

[0052] The extruder head 220 is a frustum-shaped component, coaxially connected to the inner wall of the extrusion housing 210. The outer wall of the end of the extruder head 220 has an outer conical surface that mates with the adjusting sleeve 213. The adjusting sleeve 213 is coaxially arranged with the extruder head 220, creating a uniform circumferential gap between the outer conical surface of the extruder head 220 and the inner conical surface of the adjusting sleeve 213. Molten material flows through this gap and coats the cable surface at the end of the extruder head 220. The extruder head 220 has a through-hole for the cable to pass through, ensuring that the cable is centered within the extruder head 220 when it exits.

[0053] The delivery tube 230 is a hollow tubular structure, with its outer wall coaxially and fixedly connected to the inner wall of the extrusion shell 210. One end of the delivery tube 230 passes through the fixing plate 215 and is coaxially and fixedly connected to the cable guide tube, so that the cable can accurately enter the delivery tube 230. The other end of the delivery tube 230 extends into the extrusion shell 210 and is coaxially connected to the extrusion head 220. The delivery tube 230 is used to provide stable support for the extrusion head 220 and guide the cable to the extrusion head 220.

[0054] The gaps between the adjusting sleeve 213 and the extrusion head 220, the gaps between the extrusion shell 210 and the extrusion head 220, and the gaps between the conveying pipe 230 and the extrusion shell 210 together constitute a flow channel. This flow channel is connected to the feed port 211, providing a channel for the molten material to flow from the feed port 211 to the surface of the cable.

[0055] The interior of the extruder head 220 and the delivery tube 230 together form a central channel for the cable to pass through, ensuring that the cable can pass smoothly through the entire extrusion housing 210.

[0056] During operation, the cable enters the central channel from the end of the conveying pipe 230 at a stable speed. The hopper 131 feeds raw materials into the hot melt tube 130, and the heating ring 132 heats the hot melt tube 130 to melt the raw materials. The drive motor 120 drives the hot melt tube 130 to rotate through the transmission chain 121, conveying the molten material through the feed port 211 to the flow channel. The molten material flows along the flow channel and evenly coats the surface of the cable at the end of the extrusion head 220, ultimately forming the cable insulation sheath.

[0057] However, when processing the insulation sheath of multi-stranded cables, the initial thickness of the molten material output from the flow channel is uniform, but the surface of the multi-stranded cable has uneven inter-strand gaps, which actually require more material to fill. Based on this, the outer wall of the extruder head 220 is uniformly provided with multiple convex surfaces along the circumference. These convex surfaces are used to adjust the radial distribution of the molten material within the flow channel. The extrusion device also includes a rotating assembly for driving the extruder head 220 to rotate, so that the multiple convex surfaces adapt to the outer surface contour of the cable.

[0058] Specifically, the extruder head 220 is rotatably connected to the inner wall of the delivery pipe 230. The extruder head 220 can rotate stably within the delivery pipe 230 around its own axis, and remains coaxial with the delivery pipe 230 throughout the rotation. The outer wall of the extruder head 220 has multiple convex surfaces evenly distributed circumferentially. These convex surfaces are arc-shaped, and all are identical in size and shape. The height of the convex surfaces can be adjusted and changed according to the gap size of the multi-strand cable. The convex surfaces on the outer wall of the extruder head 220 are used to change the radial distribution of the molten material within the flow channel, guiding the molten material to precisely fill the cable gap area.

[0059] The rotating assembly includes a rotating motor, the output shaft of which is connected to the extrusion head 220. The rotating motor drives the extrusion head 220 to rotate around its own axis, and the rotation speed is synchronized with the cable conveying speed, so that the convex surface of the outer wall of the extrusion head 220 can adapt to the outer surface contour of the cable in real time, and the position of the convex surface changes continuously as the cable is conveyed.

[0060] When the molten material enters the flow channel, the convex surface of the extruder head 220 generates a radial thrust on the flowing molten material, forcing some of the molten material to diffuse into areas where there was insufficient material. At the same time, the rotating motor drives the extruder head 220 to rotate according to the cable conveying speed, so that multiple convex surfaces can continuously and evenly act on the circumferential molten material, ensuring that no matter where the cable gap is rotated during conveying, the convex surfaces can guide the molten material to fill the gap area in a timely manner, achieving a smooth surface of the formed cable insulation layer.

[0061] Therefore, by altering the flow trajectory of the molten material through the convex structure of the extruder head 220, active material distribution is achieved. The molten material no longer excessively accumulates in the gap area, resulting in a completely flat surface for the formed cable insulation sheath, significantly improving appearance consistency. This avoids insulation risks in excessively thin areas and eliminates material waste in excessively thick areas, thereby improving cable insulation performance and material utilization. Simultaneously, the rotating component drives the extruder head 220 to rotate synchronously, ensuring that the adjustment function of the convex surface can perfectly adapt to the dynamic position of the cable gap.

[0062] In one embodiment, during the cable's transport from the pay-off device to the extrusion device, the cable is susceptible to fluctuations due to factors such as changes in the pay-off reel's rotation speed and the cable's own elastic deformation. These fluctuations cause the multi-stranded cable to lose its stable transport posture, leading to a tendency to wobble relative to the extrusion head 220. This wobble causes frequent, uneven contact friction between the cable's outer surface and the inner wall of the central channel of the extrusion head 220, resulting in wear on the inner wall of the extrusion head 220. Simultaneously, the cable's wobble disrupts the coaxiality between the cable and the central channel of the extrusion head 220, preventing the molten material extruded from the extrusion head 220 from uniformly coating the cable's outer surface. Therefore, the rotating assembly also includes multiple guiding units arranged axially along the central channel, which are used to straighten and limit the cable's movement.

[0063] Specifically, each guide unit includes a rotating ring 240 and multiple guide wheels 250.

[0064] Multiple rotating rings 240 are evenly distributed along the axial direction inside the conveying pipe 230. The rotating rings 240 are annular structures, and each rotating ring 240 is coaxially rotatably connected to the inner wall of the conveying pipe 230.

[0065] Multiple guide wheels 250 are evenly distributed circumferentially around a rotating ring 240, and the axes of the guide wheels 250 are all perpendicular to the axis of the rotating ring 240. Each guide wheel 250 is rotatably connected to the inner wall of the rotating ring 240 and can rotate freely around its own axis. The outer contour of the guide wheel 250 matches the contour of the cable's outer surface to ensure that the cable is effectively aligned and maintains coaxiality with the central channel when passing between the guide wheels 250. During the cable's passage through the central channel, the friction between the cable's outer surface and the outer wall of the guide wheel 250 drives the rotating ring 240 to rotate synchronously with the cable, ensuring that the guide wheels 250 always contact the cable surface.

[0066] Therefore, by arranging multiple rotating rings 240 along the axial direction inside the conveying pipe 230, and evenly distributing multiple guide wheels 250 on each rotating ring 240, the multi-strand stranded cable is circumferentially clamped, limiting the radial displacement of the cable and the relative displacement between each strand of the cable, ensuring that the cable is coaxial and stable with the central channel, reducing the contact friction between the cable and the inner wall of the extrusion head 220, reducing the wear of the extrusion head 220, and making the molten material evenly wrap around the outer surface of the cable, thereby improving the forming quality of the cable insulation layer and the service life of the equipment.

[0067] In one embodiment, to simplify the device structure, the end face of the rotating ring 240 closest to the extrusion head 220 is fixedly connected to the end face of the extrusion head 220 to achieve the rotation of the extrusion head 220, eliminating the need for a rotation motor. In this embodiment and subsequent embodiments, for ease of explanation, the rotating ring 240 closest to the extrusion head 220 is referred to as the proximal rotating ring 240.

[0068] During equipment operation, the cable is continuously fed along the central channel toward the extruder head 220. When the cable passes through the proximal rotating ring 240, its outer surface contacts the outer wall of the guide wheel 250 on the inner wall of the proximal rotating ring 240. The movement of the cable generates friction between the cable and the guide wheel 250, which drives the guide wheel 250 to rotate around its own axis, further generating a circumferential driving force on the proximal rotating ring 240, causing the proximal rotating ring 240 to rotate around the central channel axis. Since the proximal rotating ring 240 is fixedly connected to the extruder head 220, the rotation of the proximal rotating ring 240 is directly transmitted to the extruder head 220, causing the extruder head 220 to rotate synchronously around its own axis. This allows the convex surface of the outer wall of the extruder head 220 to automatically adapt to the outer surface contour of the cable, corresponding in real time to the interstrand gap position of the multi-strand twisted cable. Therefore, the near-end rotating ring 240 is driven to rotate by the friction between the cable and the guide wheel 250, which in turn drives the extruder head 220 to rotate synchronously. This eliminates the need for an additional rotating motor to drive the extruder head 220 to rotate, thus achieving dynamic correspondence between the outer convex surface of the extruder head 220 and the outer surface contour of the cable, simplifying the equipment structure.

[0069] Furthermore, the guide unit also includes multiple locking structures, which are all located between two adjacent rotating rings 240. The locking structures are used to lock the relative angular positions of adjacent rotating rings 240 according to the twist pitch of the cable, ensuring that the guide wheels 250 on the inner wall of the adjacent rotating rings 240 can continuously adapt to the spiral distribution trajectory of the cable twist gap.

[0070] Specifically, the locking structure includes a transmission rod 260. The plurality of rotating rings 240 include at least an adjacent first rotating ring and a second rotating ring.

[0071] One end of the transmission rod 260 is fixedly connected to the end face of the first rotating ring, and the transmission rod 260 extends along the axial direction of the first rotating ring. The other end of the transmission rod 260 is rotatably connected to an active pawl 261, which rotates within a specific angle range. A first elastic element is fixedly disposed between the transmission rod 260 and the active pawl 261. The first elastic element is a first spring, and the direction of the spring force always keeps the active pawl 261 facing the engagement direction.

[0072] The second rotating ring has an annular pawl groove 241 coaxially arranged on its end face facing the first rotating ring. Multiple driven pawls 242 are rotatably mounted within the pawl groove 241. All driven pawls 242 are evenly distributed circumferentially within the pawl groove 241, and each driven pawl 242 rotates within a preset rotation angle range within the pawl groove 241. A second elastic element, a second spring, is fixedly mounted between each driven pawl 242 and the second rotating ring. The spring force of the second spring tends to keep each driven pawl 242 towards the locked position.

[0073] One end of the transmission rod 260 on the first rotating ring, which is equipped with an active pawl 261, is engaged in the pawl groove 241 of the second rotating ring, which is equipped with a driven pawl 242. The active pawl 261 and the driven pawl 242 are in a one-way meshing structure, so that the first rotating ring can only move in a single circumferential direction relative to the second rotating ring.

[0074] When the first rotating ring drives the transmission rod 260 to rotate along the first circumferential direction, the driving pawl 261 pushes the driven pawl 242 to rotate against the elastic force of the second spring, causing the driven pawl 242 to approach the side wall of the pawl groove 241. At this time, the driven pawl 242 enables the driving pawl 261 to overcome the elastic force of the first spring, allowing the driving pawl 261 to smoothly pass over the driven pawl 242, realizing unidirectional rotation of the first rotating ring relative to the second rotating ring. When the first rotating ring attempts to rotate along the second circumferential direction opposite to the first circumferential direction, the driving pawl 261 engages with the driven pawl 242, and the driven pawl 242 remains in a locked position under the action of the second spring, thereby restricting the reverse rotation of the first rotating ring.

[0075] During the use of the equipment, according to the twist pitch of the cable to be processed, the relative angular positions of the adjacent first rotating ring and second rotating ring are manually adjusted so that the guide wheels 250 on the inner walls of the first rotating ring and the second rotating ring can correspond to different spiral positions of the cable twist gap respectively. During the adjustment process, when the first rotating ring rotates along the first circumferential direction, the active pawl 261 continuously passes over the driven pawl 242 until the preset angular position is reached.

[0076] The cable moves continuously along the conveying direction, and its outer surface comes into contact with the outer wall of the guide wheel 250 on the inner wall of the first and second rotating rings. The movement of the cable causes the first and second rotating rings to rotate synchronously in the second circumferential direction. At this time, the active pawl 261 and the driven pawl 242 engage, and the first rotating ring will not rotate relative to the second rotating ring, maintaining a stable relative angular position between the first and second rotating rings.

[0077] Therefore, by setting a locking structure between the first rotating ring and the second rotating ring, the first rotating ring and the second rotating ring can rotate freely in the first circumferential direction, and are locked in the second circumferential direction. This allows the first rotating ring and the second rotating ring to adjust their relative angular positions according to the twist pitch of the cable, enabling the guide wheel 250 to further and more accurately straighten the cable. At the same time, it also ensures that the positions of the first rotating ring and the second rotating ring are stable when the cable passes through, improving the uniformity of the insulation layer coating and the stability of the equipment operation.

[0078] It is understandable that the extruder head 220 and the proximal rotating ring 240 can also be connected via the transmission rod 260. One end of the transmission rod 260 is fixedly connected to the end face of the extruder head 220 near the proximal rotating ring 240. The other end of the transmission rod 260 is rotatably equipped with an active pawl 261, which engages with the pawl groove 241 of the proximal rotating ring 240, forming a one-way meshing relationship with the driven pawl 242 in the pawl groove 241.

[0079] When the device is running, when the proximal rotating ring 240 is driven to rotate along the second circumferential direction by the friction between the cable and the guide wheel 250, the active pawl 261 and the driven pawl 242 engage, and the proximal rotating ring 240 remains stationary relative to the extrusion head 220. The movement of the cable drives the guide wheel 250 on the proximal rotating ring 240 to rotate around its own axis, generating a circumferential driving force on the proximal rotating ring 240. This driving force is transmitted to the extrusion head 220 through the transmission rod 260, causing the extrusion head 220 to rotate synchronously along the second circumferential direction, ensuring that the convex surface of the outer wall of the extrusion head 220 can adapt to the outer surface contour of the cable in real time.

[0080] In one embodiment, the multiple guide wheels 250 on any one of the rotating rings 240 can all be configured as convex wheels 251. The outer wall of the convex wheel 251 is an arc-shaped protrusion structure adapted to the contour of the gap in the multi-strand cable, which can penetrate deep into the gap area to provide precise support. The number of convex wheels 251 on a rotating ring 240 is precisely matched with the number of strands in the multi-strand cable, ensuring that each strand of cable and each gap is properly supported and guided.

[0081] During the feeding of multiple strands of cable toward the extruder head 220, the cable first enters the inside of the feed tube 230 and passes through the central channel connecting the feed tube 230 and the extruder head 220. When the cable enters the inner area of ​​the rotating ring 240, the outer surface of the cable contacts the outer wall of the convex wheel 251 on the inner wall of the rotating ring 240. Multiple convex wheels 251 clamp the cable from the circumferential direction, limiting the radial displacement of the cable through clamping force, thus straightening the cable. The arc-shaped protrusion structure of the convex wheel 251 embeds into each gap area formed by the twisting of the multiple strands of cable. Through the adaptive contact between the convex wheel 251 and the gap, the relative displacement between the cable strands is limited. As the cable continues to be fed toward the extruder head 220, the cable passes through multiple rotating rings 240 arranged axially along the central channel in sequence. Each time it passes through a rotating ring 240, it is straightened by the convex wheel 251 inside that rotating ring 240, ensuring that the cable remains stable throughout the entire central channel. During this process, the continuous movement of the cable generates a continuous frictional force between the outer surface of the cable and the outer wall of the convex wheel 251. This frictional force drives the convex wheel 251 to rotate around its own axis. At the same time, the rotation of the convex wheel 251 generates a circumferential driving force on the rotating ring 240, which in turn drives the rotating ring 240 to rotate around the axis of the conveying pipe 230.

[0082] In one embodiment, the multiple guide wheels 250 on any one rotating ring 240 can all be configured as concave wheels 252. The outer wall of the concave wheel 252 is an arc-shaped groove structure adapted to the outer contour of each cable strand, ensuring reliable wrapping of the single cable strand. The number of concave wheels 252 on a rotating ring 240 is precisely matched with the number of strands in the multi-strand cable, ensuring that each cable strand and each gap is adequately supported and guided.

[0083] During the feeding of multiple cables toward the extruder head 220, the cables first enter the feed tube 230 and pass through the central channel connecting the feed tube 230 and the extruder head 220. When the cables enter the inner area of ​​the rotating ring 240, the outer surface of the cables contacts the outer wall of the concave rollers 252 on the inner wall of the rotating ring 240. Multiple concave rollers 252 clamp the cables circumferentially, limiting the radial displacement of the cables through clamping force, thus straightening the cables. The arc-shaped groove structure of the concave rollers 252 completely conforms to the outer wall of each cable, defining the position of each cable through the wrapping contact of the grooves with the individual cables. As the cables continue to be fed toward the extruder head 220, they pass sequentially through multiple rotating rings 240 arranged axially along the central channel. Each time a cable passes through a rotating ring 240, it is straightened by the concave rollers 252 within that rotating ring 240, ensuring that the cables remain stable throughout the entire central channel. During this process, the continuous movement of the cable generates a continuous frictional force between the outer surface of the cable and the outer wall of the concave wheel 252. This frictional force drives the concave wheel 252 to rotate around its own axis. At the same time, the rotation of the concave wheel 252 generates a circumferential driving force on the rotating ring 240, which in turn drives the rotating ring 240 to rotate around the axis of the conveying pipe 230.

[0084] It is understandable that any rotating ring 240 may also have multiple convex wheels 251 and multiple concave wheels 252 rotatably arranged simultaneously. The convex wheels 251 and concave wheels 252 are arranged alternately in the circumferential direction, which can provide wrapping support and embedded support for the outer wall and the gap area on both sides of each cable at the same time, thereby forming continuous and alternating constraint points in the circumferential direction, which can further suppress the radial sway and torsion of the cable.

[0085] In one embodiment, in order to clean the surface of each conductor in the cable before covering the cable with an insulating outer sheath, the extrusion molding equipment for cable insulation sheath provided by the present invention further includes a cleaning device. The cleaning device is used to adsorb and clean the surface of each conductor when the cable passes through the central channel to ensure the bonding quality between the insulation layer and the conductor.

[0086] Specifically, the cleaning device includes a negative pressure source (not shown in the figure) and an adsorption channel (not shown in the figure). One end of the adsorption channel is connected to the negative pressure source, and its adsorption end is connected to the central channel, so that the negative pressure can act on the surface of the cable passing through the central channel.

[0087] At least one rotating ring 240 has multiple guide wheels 250, all of which are convex wheels 251. Each convex wheel 251 has multiple adsorption holes 253 on its wheel body, which penetrate the wheel body and extend from the outer wall of the wheel body to the interior of the wheel body. Simultaneously, the outer wall of the rotating ring 240 is coaxially provided with an annular adsorption groove 244, which is connected to the adsorption channel. The rotating ring 240 also has an internal channel 243, through which the adsorption holes 253 and the adsorption groove 244 are kept connected, forming a complete adsorption path from the negative pressure source to the cable surface.

[0088] During use, when the cable passes through the rotating ring 240, the arc-shaped protrusion on the outer wall of the convex wheel 251 embeds into the gap between two adjacent wires, spreading the wires and widening the gap between them. This allows the adsorption holes 253 to more effectively contact and suck up impurities within the gap. Simultaneously, a negative pressure source continuously provides negative pressure, forming a stable airflow path through the adsorption channel, adsorption groove 244, internal channel 243, and adsorption holes 253. As the cable passes through, impurities between each wire are drawn into the adsorption holes 253 under negative pressure. They are then collected or discharged through the internal channel 243, adsorption groove 244, and adsorption channel, efficiently sucking up impurities within the gap. This cleans the cable surface and the gaps between each wire, eliminating the impact of impurities on the bonding between the insulation layer and the cable wires, preventing defects such as bubbles and delamination in the insulation layer, and improving the cable's insulation performance and overall structural stability.

[0089] In one embodiment, to facilitate the assembly and disassembly of the extruder head 220, an annular guide groove is coaxially arranged on the inner wall of the conveying pipe 230 in the circumferential direction, with the opening of the guide groove facing the inner side of the conveying pipe 230. Multiple mounting holes are radially formed on the outer wall of the extruder head 220, evenly distributed circumferentially. A limiting slider 221 is slidably disposed within each mounting hole. The limiting slider 221 can reciprocate radially along the extruder head 220. Multiple limiting sliders 221 can be embedded within the guide groove. The end of the limiting slider 221 near the guide groove has an arc-shaped structure to ensure smooth sliding within the guide groove. A third elastic element, a third spring 222, is provided between each limiting slider 221 and the bottom of the mounting hole of the extruder head 220. One end of the third spring 222 is fixedly connected to the bottom of the mounting hole, and the other end is fixedly connected to the end face of the limiting slider 221. The elastic force of the third spring 222 always extends outward along the radial direction of the extruder head 220, pushing the limit slider 221 out of the outer wall of the extruder head 220 and embedding it into the guide groove.

[0090] During equipment operation, when the extrusion head 220 rotates around its own axis, the extrusion head 220 will drive the limiting slider 221 to rotate synchronously. The limiting slider 221 will slide in the guide groove along the circumferential direction. The groove wall of the guide groove forms a radial constraint on the limiting slider 221, ensuring that the extrusion head 220 always remains coaxial with the conveying pipe 230 during rotation and has no radial offset.

[0091] When it is necessary to disassemble the extruder head 220, pull the extruder head 220 outward along the axial direction. The limiting slider 221 is squeezed by the edge of the guide groove and retracts radially inward against the elastic force of the third spring 222. Continue to pull the extruder head 220 outward until the limiting slider 221 is completely disengaged from the guide groove, and then remove the extruder head 220 from the delivery pipe 230.

[0092] When installing the extruder head 220, align the extruder head 220 with the center channel of the delivery pipe 230 and insert it axially. The limiting slider 221 is pressed back by the inner wall of the delivery pipe 230. Continue to advance the extruder head 220 until the limiting slider 221 reaches the guide groove position. The elastic force of the third spring 222 causes the limiting slider 221 to pop out and embed into the guide groove, completing the installation of the extruder head 220.

[0093] Therefore, the guide groove on the inner wall of the conveying pipe 230 and the limiting slider 221 that slides radially on the outer wall of the extruder head 220 ensure that the extruder head 220 remains coaxial with the conveying pipe 230 during rotation. At the same time, the extruder head 220 can be assembled and disassembled without additional tools, making the operation simple and quick.

[0094] Furthermore, for ease of installation and maintenance, the delivery pipe 230 is designed as a detachable two-half structure, meaning it is divided into two identical halves by symmetrically arranged cross-sections along the axial direction. The two halves are rigidly connected by connecting bolts. During installation, the two halves can be snapped together from both sides of the central channel and then tightened with the connecting bolts to complete the assembly of the delivery pipe 230. Similarly, when it is necessary to disassemble or replace the delivery pipe 230, the two halves can be separated simply by loosening the connecting bolts, simplifying the installation and maintenance process.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An extrusion molding apparatus for cable insulation sheath, characterized in that, The device includes an extrusion apparatus comprising an extrusion shell, an extrusion head, and a rotating assembly. The extrusion shell has a through hole extending through both axial end faces and a feed inlet. The extrusion head is coaxially rotatably connected to the inner wall of the extrusion shell, and a flow channel for molten material to pass through is formed between the extrusion head and the extrusion shell. The flow channel communicates with the feed inlet. The extrusion head has a central channel for a cable to pass through inside, and a plurality of convex surfaces are uniformly arranged circumferentially on the outer wall of the extrusion head. The plurality of convex surfaces are used to adjust the radial distribution of the molten material in the flow channel. The rotating assembly is used to drive the extrusion head to rotate so that the plurality of convex surfaces adapt to the outer surface contour of the cable. The rotating assembly includes multiple guide units, which are arranged axially in the central channel and are used to straighten and limit the cable. The extrusion device further includes a conveying pipe, the outer wall of which is coaxially fixedly connected to the extrusion housing, and the end of the conveying pipe extends into the extrusion housing; the extrusion head is rotatably connected to the end of the conveying pipe, and the central channel passes through the conveying pipe and the extrusion head; Each of the guiding units includes a rotating ring and a plurality of guide wheels. The rotating ring is coaxially rotatably connected to the inner wall of the conveying pipe. The plurality of guide wheels are evenly distributed circumferentially on the inner wall of the rotating ring and are rotatably connected to the inner wall of the rotating ring. The outer wall of each guide wheel is adapted to the outer surface contour of the cable. The guide wheels are used to straighten the cable when it passes through. As the cable passes through the central channel, the friction between the cable and the guide wheel can drive the rotating ring to rotate. The rotating ring closest to the extrusion head is fixedly connected to the extrusion head. When the cable passes through the central channel, the cable can drive the rotating ring to rotate, thereby causing the extrusion head to rotate synchronously.

2. The extrusion molding equipment for cable insulation sheath according to claim 1, characterized in that, The guiding unit also includes multiple locking structures, which are disposed between adjacent rotating rings. The locking structures are used to lock the relative angular positions of adjacent rotating rings according to the twist pitch of the cable.

3. The extrusion molding equipment for cable insulation sheath according to claim 2, characterized in that, The locking structure includes a transmission rod, one end of which is fixedly connected to the end face of a rotating ring; the other end of the transmission rod is rotatably provided with an active pawl, and a first elastic element is provided between the transmission rod and the active pawl, the first elastic element being used to keep the active pawl tending towards the engagement direction; the other end face of the rotating ring is coaxially provided with a pawl groove, and the rotating ring is rotatably provided with multiple driven pawls in the pawl groove, the multiple driven pawls being evenly distributed circumferentially in the pawl groove; a second elastic element is provided between the rotating ring and one of the driven pawls, each of the second elastic elements being used to keep one of the driven pawls tending towards the locked position; The drive rod of one of the rotating rings can engage in the pawl groove of the adjacent rotating ring, the driving pawl and the driven pawl being used to enable the two adjacent rotating rings to rotate relative to each other in only a single circumference.

4. The extrusion molding equipment for cable insulation sheath according to claim 1, characterized in that, It also includes a cleaning device for adsorbing and cleaning the surface of the cable as it passes through the central channel.

5. The extrusion molding equipment for cable insulation sheath according to claim 4, characterized in that, The cleaning device includes a negative pressure source and an adsorption channel. The adsorption channel is connected to the negative pressure source, and the adsorption end of the adsorption channel is connected to the central channel.

6. The extrusion molding equipment for cable insulation sheath according to claim 5, characterized in that, The guide wheel has multiple through-holes for adsorption, and the outer wall of the rotating ring has an adsorption groove coaxially connected to the adsorption channel. The rotating ring also has an internal channel connecting the adsorption holes and the adsorption groove. The plurality of guide wheels on one of the rotating rings are configured as convex wheels, the contours of which are adapted to the gaps between adjacent wires in the cable. The convex wheels are used to spread the adjacent wires apart when straightening the cable so that the suction holes can suck up impurities in the gaps between the wires.

7. The extrusion molding equipment for cable insulation sheath according to claim 1, characterized in that, The inner wall of the conveying pipe is provided with an annular guide groove, and the outer wall of the extrusion head is provided with a limit slider that slides radially. A third elastic element is provided between the limit slider and the extrusion head. The elastic force of the third elastic element always causes the limit slider to extend out of the extrusion head and embed into the guide groove.

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