Polypropylene insulated cable extruder

Abstract

The invention relates to the technical field of cable preparation, in particular to a polypropylene insulated cable extruder, which comprises an extruder main body, an extrusion motor, an extrusion head, an extruder auxiliary machine and two crawler belt mechanisms, the extruder further comprises a first spiral feeder, a filter plate, a backflow channel and a second spiral feeder, the first spiral feeder is rotationally installed in the extruder body, the extrusion motor is in transmission connection with the first spiral feeder, two sections of first spiral blades are arranged on the first spiral feeder, the filter plate is installed on the middle rear portion of the extruder body, and the backflow channel is installed at the bottom of the extruder body. An inlet of the backflow channel is located below the filter plate, an outlet of the backflow channel is located at the end, close to the extrusion motor, of the extruder body, and the second spiral feeder is rotationally installed in the backflow channel and is in transmission connection with an output shaft of the extrusion motor through a transmission assembly. Conveying of molten raw materials and backflow of non-molten raw materials are carried out separately, raw material conveying is prevented from being hindered, and the reliability of the extruder is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cable preparation, and particularly to a polypropylene insulated cable extruder. Background Art

[0002] The manufacturing process of polypropylene insulated cables is that polypropylene cable materials are extruded by an extruder onto a stranded conductor and then cooled by a water cooling device to obtain polypropylene cables. The Chinese patent application with the publication number CN119626675A in the prior art proposes an insulating layer extruder for cable manufacturing. The extruder body is fixedly installed at the upper end of a bracket. The extruder body includes a housing. A rotating shaft is provided at the center of the housing. One end of the rotating shaft passes through the housing and is fixedly connected to the output shaft of a speed changer. A transmission gear is fixedly connected to the input shaft of the speed changer. The transmission gear meshes with a gear on the output shaft of a motor fixedly connected to the bracket. The spiral direction of the spiral plate II is opposite to that of the spiral plate I and the spiral plate III. And a movable device is fixedly connected to the opposite surface of the spiral plate II and the spiral plate I. This extruder can push the raw materials that have not reached the molten state towards the spiral plate I by the rotation of the spiral plate II until they reach the molten state and then flow through the perforation to the position of the spiral plate III.

[0003] It uses the spiral II and the spiral plate I with opposite conveying directions to convey the molten raw materials and filter the unmolten raw materials, inevitably causing the raw materials to produce a head-on collision, affecting the reliable conveying of the raw materials. Although there are perforations on the spiral II, the unmolten raw materials will block the perforations for a short time, resulting in untimely feeding or even material cut-off, leading to poor working reliability of the above-mentioned extruder. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a polypropylene insulated cable extruder that separates the conveyance of molten raw materials and the reflux of unmolten raw materials, avoids hindering the conveyance of raw materials, and improves the reliability of the extruder.

[0005] A polypropylene-insulated cable extruder of the present invention includes an extruder main body, an extrusion motor, an extrusion head, an extruder auxiliary machine, and two track mechanisms. A heater is installed on the extruder main body. A melting chamber is arranged inside the extruder main body. A feeding port communicating with the melting chamber is arranged at one end of the extruder main body close to the extrusion motor. A discharging port communicating with the melting chamber is arranged at the other end of the extruder main body. The extrusion head is installed on the discharging port of the extruder main body. The extruder auxiliary machine is located outside the output end of the extrusion head. Two track mechanisms are oppositely installed on the extruder auxiliary machine. The two track mechanisms are used for cooling and conveying the cable. It also includes a first screw feeder, a filter plate, a reflux channel, and a second screw feeder. The first screw feeder is rotatably installed in the melting chamber of the extruder main body. The output shaft of the extrusion motor is in transmission connection with the first screw feeder. Two sections of first screw blades are arranged on the outer wall of the first screw feeder. The filter plate is installed in the middle and rear part of the melting chamber of the extruder main body. The first screw blades at both ends of the first screw feeder are respectively located on both sides of the filter plate. The reflux channel is installed at the bottom of the extruder main body. The inlet of the reflux channel is located below the filter plate. The outlet of the reflux channel is located at one end of the extruder main body close to the extrusion motor. The second screw feeder is rotatably installed in the reflux channel. A second screw blade is arranged on the outer wall of the second screw feeder. The second screw feeder is in transmission connection with the output shaft of the extrusion motor through a transmission component. During operation, the conductor core passes through the channel of the extrusion head. The polypropylene raw material enters the melting chamber of the extruder main body through the feeding hole. The extrusion motor drives the first screw feeder and the second screw feeder to rotate. The first section of the first screw blade of the first screw feeder pushes the raw material towards the discharging port. The raw material is heated and melted during the conveying process. The filter plate filters the raw material. The qualified melted raw material passes through the filter holes of the filter plate and is pushed out of the discharging port by the second section of the first screw blade of the first screw feeder and enters the extrusion head and wraps around the conductor core to form a cable. After the cable exits the extrusion head, it is rolled and shaped by the two track mechanisms and conveyed to the next working station backward. At the same time, the cooling water tank and the spraying mechanism on the extruder auxiliary machine cool down the cable. During this process, the unmolten and unqualified raw material particles intercepted by the filter plate are prevented from blocking the filter holes of the filter plate under the scraping action of the end of the first screw blade of the first screw feeder. And the unmolten and unqualified raw material particles will fall to the bottom of the melting chamber of the extruder main body under the action of gravity and enter the reflux channel through the inlet. The rotating second screw feeder conveys the mixture of the unmolten raw material and the melted raw material in the reflux channel in the reverse direction and makes the mixture return to the melting chamber of the extruder main body through the outlet of the reflux channel to be heated and melted again. Compared with the prior art, the conveying and reflux of the raw material are carried out separately, which will not cause the phenomenon of raw material counterflow in the melting chamber of the extruder main body, avoid hindering the raw material conveying, avoid the situation of untimely feeding and material breakage caused by the blockage of the filter holes by the unmolten raw material, and improve the working reliability of the extruder.

[0006] Preferably, it further includes a plurality of scraping plates, which are evenly installed on the outer wall of the first screw feeder in a circumferential manner. The plurality of scraping plates scrape the side of the filter plate facing the extrusion motor, and the outer ends of the plurality of scraping plates scrape the inner wall of the extruder body. By arranging the plurality of scraping plates to scrape the side of the filter plate and the inner wall of the extruder body, the plurality of scraping plates scrape off the raw material particles intercepted on the filter plate and guide them outward under the action of centrifugal force, finally enabling the raw material particles to enter the reflux channel more efficiently through the inlet, thereby improving the reflux efficiency of solid particles.

[0007] Preferably, it further includes two hoppers, a three-way valve and two covers. Both of the two hoppers are provided with a storage chamber, and both of the two hoppers are provided with an upper feeding port communicating with the discharge chamber, and both of the two hoppers are provided with a lower discharge port communicating with the discharge chamber. The lower discharge ports of the two hoppers are respectively connected to the first channel and the second channel of the three-way valve, and the third channel of the three-way valve is connected to the feeding port of the extruder body. The two covers are respectively installed in the storage chambers of the two hoppers through the two upper feeding ports in a liftable and slidable manner, and sliding seals are arranged between the edges of the two covers and the inner walls of the storage chambers of the two hoppers. The two hoppers form a double-station. By switching the channel connection mode of the three-way valve, raw materials can be alternately conveyed to the extruder body to achieve uninterrupted feeding and improve work efficiency. By arranging the two covers, impurities in the air entering the raw materials in the two hoppers are reduced, pollution is reduced, and the quality of the cable insulation layer is improved.

[0008] Preferably, it further includes an exhaust pipe and a heat-resistant diaphragm. The exhaust pipe is installed on the top of the extruder body, the lower end of the exhaust pipe is communicated with the melting chamber of the extruder body, a heat-resistant diaphragm is installed inside the exhaust pipe, and a joint is arranged at the upper end of the exhaust pipe. The joint of the exhaust pipe is connected to an external exhaust system. The exhaust system evacuates the gas impurities in the melting chamber of the extruder body through the exhaust pipe, reduces the impurity bubbles in the raw materials, avoids the conductive components in the impurity gas from affecting the insulation performance, and improves the quality of the cable insulation layer.

[0009] Preferably, it also includes an annular sleeve and multiple inserts, the annular sleeve is sleeved on the outer wall of the discharge port of the extruder body, an annular auxiliary material channel is arranged inside the annular sleeve, an auxiliary material interface connected with the auxiliary material channel is arranged on the annular sleeve, multiple inserts are uniformly inserted on the outer wall of the discharge port of the extruder body, the inner ends of the multiple inserts are all provided with auxiliary material outlets, the auxiliary material outlets are all located in the discharge port of the extruder body, the outer ends of the multiple inserts are all provided with auxiliary material inlets, and the auxiliary material inlets are all located in the auxiliary material channel of the annular sleeve; auxiliary materials such as insulating gases, such as carbon dioxide, etc., or foaming materials, such as bicarbonate, azodicarbonamide, etc., or elastic vacuum spheres, or volatile insulating polymer particles, etc. are input into the auxiliary material channel of the annular sleeve through the auxiliary material interface, and the auxiliary materials enter into the multiple inserts respectively through the auxiliary material inlets, and then pass through The auxiliary material outlets through multiple insert tubes are distributed into the molten raw material, the gas auxiliary material is wrapped by the raw material to directly form an insulating bubble, the foaming material foams and expands when heated to form an insulating bubble, the hollow sphere is wrapped by the raw material to directly form a vacuum insulating bubble, the volatile insulating polymer particles are vaporized and expanded when heated to form a vacuum insulating bubble after the polypropylene insulating layer is cooled, and the insulating polymer particles are solidified on the inner wall of the vacuum insulating bubble, so as to achieve the purpose of distributing insulating bubbles in the cable insulation layer, improve flexibility and lightweight on the basis of ensuring insulation performance; when the auxiliary material is an elastic vacuum sphere or a volatile insulating polymer particle, the insulating bubble in the insulating layer is a vacuum insulating bubble, and the vacuum insulating bubble is squeezed when the cable is bent. Since there is no gas inside, it will not be squeezed and broken from the inside to the outside by the gas, thereby reducing cracks in the insulating layer and improving quality.

[0010] Preferably, it also includes a track ring and a drive shaft, the outer ends of the multiple plugs all extend out of the outer wall of the annular sleeve, the multiple plugs are all slidably connected with the annular sleeve and the outer wall of the discharge port of the extruder body, the concentric rings of the track ring are arranged on the annular sleeve, the interior of the track ring is a track that is not concentric with the annular sleeve, the outer ends of the multiple plugs are evenly slidably connected with the track of the track ring, a gear ring is arranged on the outer wall of the track ring, and the drive shaft is rotatably installed on the outer wall of the extruder body, one end of the drive shaft is connected to the screw feeder 2 through a transmission pair, and the other end of the drive shaft is meshed with the gear ring of the track ring through a gear; the track of the track ring can be a non-concentric circle such as an eccentric circle, cam shape, elliptical or sawtooth shape of the annular sleeve, when the screw feeder 2 rotates, the drive shaft is driven to rotate through the transmission pair, and the drive shaft drives the track ring to rotate through the gear meshing gear ring, and the track of the track ring drives the multiple plugs to reciprocate along the radial direction of the annular sleeve, so that the multiple plugs transport the auxiliary material to different positions in the discharge port of the extruder body, so that the auxiliary material is distributed more evenly.

[0011] Preferably, it further includes an auxiliary material tank, a piston cylinder, an arc plate, a lever, a torsion spring, a push rod mechanism, a piston plate and a push block. The auxiliary material tank is installed on the main body of the extruder. An auxiliary material storage chamber is arranged inside the auxiliary material tank. The piston cylinder is installed at the bottom of the auxiliary material storage chamber of the auxiliary material tank. A long strip opening is arranged at the upper part of the piston cylinder. An auxiliary material output pipe is arranged at the left end of the piston cylinder. The auxiliary material output pipe is connected to the auxiliary material interface of the annular sleeve. The arc plate is rotatably installed on the outer wall of the upper part of the piston cylinder. The left end of the arc plate is rotatably connected to the left end of the piston cylinder through a rotating shaft. The two ends of the torsion spring are respectively connected to the arc plate and the piston cylinder. The torsion force of the torsion spring makes the arc plate close the long strip opening of the piston cylinder. A lever is arranged at the right end of the arc plate. The lever extends into the interior of the right end of the piston cylinder. The push rod mechanism is installed on the outer wall of the auxiliary material tank. The piston rod of the push rod mechanism extends into the piston cylinder from the right end. The piston plate is installed at the end of the piston rod of the push rod mechanism. The lever is rotatably connected to the piston rod of the push rod mechanism. A push block is installed on the right side wall of the piston plate. An inclined guiding surface is arranged on the push block. The guiding surface of the push block faces the lever. Solid auxiliary material particles are stored in the auxiliary material storage chamber of the auxiliary material tank. The piston rod of the push rod mechanism reciprocates to contract to the right and then extend to the left. When the piston rod of the push rod mechanism contracts to the right, it drives the piston plate to move to the right in the piston cylinder. When the piston plate reaches the right end of the piston cylinder, the guiding surface of the push block begins to squeeze the lever, thereby driving the lever to rotate around the piston rod of the push rod mechanism. The lever drives the arc plate to rotate to one side of the piston cylinder to open the long strip opening, so that the auxiliary material particles enter the piston cylinder. At this time, the piston rod of the push rod mechanism extends to the left. The piston plate drives the push block to move to the left. After the push block is separated from the lever, the arc plate closes the long strip opening of the piston cylinder under the action of the torsion force of the torsion spring. At this time, the piston plate continues to move to the left to push the auxiliary material particles in the piston cylinder to the left and send them into the auxiliary material channel of the annular sleeve through the auxiliary material output pipe. Repeating the above actions realizes the continuous feeding of the auxiliary material particles.

[0012] Preferably, it further includes a guiding sleeve, a plurality of balls, a plurality of pulleys, a worm wheel disc, a second motor, and a worm. The guiding sleeve is rotatably installed on the conductor core input port of the extrusion head. A plurality of balls are circumferentially and rotatably installed on the inner wall of the guiding sleeve, and the plurality of balls respectively rollingly contact two adjacent metal wires in the conductor core. A plurality of pulleys are circumferentially and rotatably installed on the inner wall of the track ring, and the plurality of pulleys respectively rollingly contact the outer walls of multiple metal wires in the conductor core. The worm wheel disc is concentrically installed on the outer wall of the guiding sleeve. The second motor is installed on the extrusion head, and the output shaft of the second motor is concentrically installed with the worm. The worm meshes with the worm wheel disc. After passing through the guiding sleeve, the conductor core enters the extrusion head. The plurality of balls are respectively arranged between two adjacent metal wires of the conductor core, so that the plurality of balls perform rolling limit on the outer walls of the multiple metal wires. At the same time, the plurality of pulleys are respectively arranged on the outer sides of the multiple metal wires of the conductor core and respectively rollingly contact the multiple metal wires, thereby performing rolling limit on the multiple metal wires and improving the stability of the conductor core. The second motor drives the worm to rotate, and the worm meshes with the worm wheel disc to drive the guiding sleeve to rotate, which can adjust the angles of the plurality of balls and the plurality of pulleys and make the plurality of balls and the plurality of pulleys rotate, so as to adapt to the metal wires arranged side by side or wound.

[0013] Preferably, it further includes a bearing seat, a second gear ring, a third motor, a third gear, a first turntable, two first pressure rollers, a second turntable, and two second pressure rollers. The bearing seat is rotatably installed on the cable outlet of the extrusion head. The second gear ring is concentrically installed on the outer wall of the bearing seat. The third motor is installed on the extrusion head, and the output shaft of the third motor is concentrically installed with the third gear. The third gear meshes with the second gear ring. The first turntable is installed on the bearing seat, and a first cable channel is arranged in the middle of the first turntable. Two first pressure rollers are relatively and rotatably installed on both sides of the first cable channel. The second turntable is installed on the first turntable, and a second cable channel is arranged in the middle of the second turntable. Two second pressure rollers are relatively and rotatably installed on both sides of the second cable channel. The two first pressure rollers and the two second pressure rollers are vertically arranged. The cable wrapped with the insulating layer is output from the extrusion head through the cable outlet and passes through the first cable channel of the first turntable and the second cable channel of the second turntable. The two first pressure rollers and the two second pressure rollers respectively rollingly contact the four side outer walls of the cable. The third motor drives the third gear to rotate, and the third gear meshes with the second gear ring to drive the bearing seat to rotate. The bearing seat drives the first turntable and the second turntable to rotate. The first turntable drives the two first pressure rollers to rotate around the cable, and the second turntable drives the two second pressure rollers to rotate around the cable, so as to roll and shape the outer surface of the insulating layer of the cable by the two first pressure rollers and the two second pressure rollers and improve the quality of the insulating layer.

[0014] Preferably, a grinding machine and a cooling fan are further included. The grinding machine is installed on the first turntable and is used to remove the burrs on the outer wall of the cable insulation layer. The cooling fan is installed on the second turntable and blows air on the cable to cool the cable insulation layer. The grinding machine rotates with the first turntable, and the grinding cutter head of the grinding machine grinds and removes the burrs on the outer wall of the cable insulation layer, improving the smoothness of the outer surface of the cable. The operation of the cooling fan to blow air on the cable is beneficial to reducing the cable temperature and enabling the cable insulation layer to be quickly shaped.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The transportation and reflux of the raw materials are separated, and no counterflow phenomenon of the raw materials will occur in the melting chamber of the extruder body, avoiding obstacles to the transportation of the raw materials, preventing the unmolten raw materials from blocking the filter holes and causing untimely feeding and material breakage, and improving the working reliability of the extruder. Brief Description of the Drawings

[0016] Figure 1 is the structural schematic diagram of the present invention; Figure 2 is the axonometric schematic diagram of the present invention; Figure 3 is the side sectional structural schematic diagram of the present invention; Figure 4 is the front sectional structural schematic diagram of the present invention; Figure 5 is the structural schematic diagram of structures such as the extruder body, the extrusion motor, the first screw feeder, the filter plate, the reflux channel, the second screw feeder, the hopper, the three-way valve, the cover plate, and the suction pipe; Figure 6 is the front view structural schematic diagram of structures such as the insertion tube and the track ring; Figure 7 is the structural schematic diagram of the decomposition state of structures such as the annular sleeve, the insertion tube, the track ring, and the drive shaft; Figure 8 is the schematic diagram of structures such as the auxiliary material tank, the piston cylinder, the arc plate, the lever, the push rod mechanism, the piston plate, and the push block; Figure 9 is the exploded structural schematic diagram of structures such as the piston cylinder, the arc plate, the lever, the torsion spring, the push rod mechanism, the piston plate, and the push block; Figure 10 is the axonometric schematic diagram of the extrusion head; Figure 11 is the structural schematic diagram of structures such as the guide sleeve, the ball, the pulley, the worm wheel disc, the second motor, and the worm; Figure 12 is the structural schematic diagram of the decomposition state of structures such as the bearing seat, the second gear ring, the third motor, the third gear, the first turntable, the first pressure roller, the second turntable, the second pressure roller, the grinding machine, and the cooling fan.

[0017] Reference numerals in the drawings: 1, main body of the extruder; 2, extrusion motor; 3, extrusion head; 4, auxiliary machine of the extruder; 5, crawler mechanism; 6, first screw feeder; 7, filter plate; 8, reflux channel; 9, second screw feeder; 10, scraper; 11, hopper; 12, three-way valve; 13, cover plate; 14, suction pipe; 15, heat-resistant diaphragm; 16, annular sleeve; 17, insertion tube; 18, track ring; 19, drive shaft; 20, auxiliary material tank; 21, piston cylinder; 22, arc plate; 23, lever; 24, torsion spring; 25, push rod mechanism; 26, piston plate; 27, push block; 28, guide sleeve; 29, ball; 30, pulley; 31, worm wheel disc; 32, second motor; 33, worm; 34, bearing seat; 35, second gear ring; 36, third motor; 37, third gear; 38, first turntable; 39, first pressure roller; 40, second turntable; 41, second pressure roller; 42, grinding machine; 43, air cooler. Detailed implementation mode

[0018] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0019] Example 1, as Figures 1 to 5As shown in the figure, a polypropylene insulated cable extruder includes an extruder main body 1, an extrusion motor 2, an extrusion head 3, an extruder auxiliary machine 4, and two track mechanisms 5. A heater is installed on the extruder main body 1. A melting chamber is provided inside the extruder main body 1. A feeding port communicating with the melting chamber is provided at one end of the extruder main body 1 close to the extrusion motor 2. A discharge port communicating with the melting chamber is provided at the other end of the extruder main body 1. The extrusion head 3 is installed on the discharge port of the extruder main body 1. The extruder auxiliary machine 4 is located outside the output end of the extrusion head 3. Two track mechanisms 5 are oppositely installed on the extruder auxiliary machine 4. The two track mechanisms 5 are used for cooling and conveying the cable. It also includes a first screw feeder 6, a filter plate 7, a reflux channel 8, and a second screw feeder 9. The first screw feeder 6 is rotatably installed in the melting chamber of the extruder main body 1. The output shaft of the extrusion motor 2 is in transmission connection with the first screw feeder 6. Two sections of first screw blades are provided on the outer wall of the first screw feeder 6. The filter plate 7 is installed in the middle and rear part of the melting chamber of the extruder main body 1. The two ends of the first screw blades of the first screw feeder 6 are respectively located on both sides of the filter plate 7. The reflux channel 8 is installed at the bottom of the extruder main body 1. The inlet of the reflux channel 8 is located below the filter plate 7. The outlet of the reflux channel 8 is located at one end of the extruder main body 1 close to the extrusion motor 2. The second screw feeder 9 is rotatably installed in the reflux channel 8. A second screw blade is provided on the outer wall of the second screw feeder 9. The second screw feeder 9 is in transmission connection with the output shaft of the extrusion motor 2 through a transmission assembly. It also includes a plurality of scraping plates 10. The plurality of scraping plates 10 are evenly installed on the outer wall of the first screw feeder 6 in a circumferential manner. The plurality of scraping plates 10 all scrape the side of the filter plate 7 facing the extrusion motor 2. The outer ends of the plurality of scraping plates 10 all scrape the inner wall of the extruder main body 1. It also includes two hoppers 11, a three-way valve 12, and two cover plates 13. Both of the two hoppers 11 are provided with a storage chamber. Both of the two hoppers 11 are provided with an upper feeding port communicating with the discharge chamber. Both of the two hoppers 11 are provided with a lower discharge port communicating with the discharge chamber. The lower discharge ports of the two hoppers 11 are respectively communicated with the first channel and the second channel of the three-way valve 12. The third channel of the three-way valve 12 is communicated with the feeding port of the extruder main body 1. The two cover plates 13 are respectively installed in the storage chambers of the two hoppers 11 in a liftable and slidable manner through the two upper feeding ports. A sliding seal is provided between the edges of the two cover plates 13 and the inner walls of the storage chambers of the two hoppers 11. It also includes an exhaust pipe 14 and a heat-resistant diaphragm 15. The exhaust pipe 14 is installed on the top of the extruder main body 1. The lower end of the exhaust pipe 14 is communicated with the melting chamber of the extruder main body 1. The heat-resistant diaphragm 15 is installed inside the exhaust pipe 14. A joint is provided at the upper end of the exhaust pipe 14.

[0020] During operation, the conductor core passes through the channel of the extrusion head 3. The two hoppers 11 form a two-station. By switching the channel connection mode of the three-way valve 12, raw materials can be alternately conveyed to the main body 1 of the extruder to achieve continuous feeding. By providing two cover plates 13, the entry of impurities in the air into the raw materials in the two hoppers 11 is reduced, pollution is reduced, and the quality of the cable insulation layer is improved; the polypropylene raw materials enter the melting chamber of the main body 1 of the extruder through the feeding hole. The extrusion motor 2 drives the first screw feeder 6 and the second screw feeder 9 to rotate. The first spiral blade of the first section of the first screw feeder 6 pushes the raw materials towards the discharge port. During the conveying process of the raw materials, they are heated and melted. The filter plate 7 filters the raw materials. The qualified melted raw materials pass through the filter holes of the filter plate 7 and are then pushed out of the discharge port by the second spiral blade of the first screw feeder 6 and enter the extrusion head 3 and wrap around the conductor core to form a cable. After the cable exits the extrusion head 3, it is rolled and shaped by the two track mechanisms 5 and conveyed to the next station. At the same time, the cooling water tank and spraying mechanism on the auxiliary machine 4 of the extruder cool down the cable; during this process, the connector of the air extraction pipe 14 is connected to an external air extraction system. The air extraction system extracts the gas impurities in the melting chamber of the main body 1 of the extruder through the air extraction pipe 14, reduces the impurity bubbles in the raw materials, and avoids the conductive components in the impurity gas from affecting the insulation performance, improving the quality of the cable insulation layer. The unmolten and unqualified raw material particles intercepted by the filter plate 7 are scraped by multiple scraping plates 10 on the side of the filter plate 7 and the inner wall of the main body 1 of the extruder. The multiple scraping plates 10 scrape off the raw material particles intercepted on the filter plate 7, prevent the filter holes of the filter plate 7 from being blocked, and are guided outwards under the action of centrifugal force. Finally, the raw material particles can enter the reflux channel 8 more efficiently through the inlet. The rotating second screw feeder 9 conveys the mixture of the unmolten raw materials and the melted raw materials in the reflux channel 8 in the reverse direction, and the mixture returns to the melting chamber of the main body 1 of the extruder through the outlet of the reflux channel 8 and is heated and melted again. Compared with the prior art, the conveying and reflux of the raw materials are carried out separately, and there will be no impact phenomenon of the raw materials in the melting chamber of the main body 1 of the extruder, avoiding obstacles to the raw material conveying, avoiding the situation of untimely feeding and material breakage caused by the blockage of the filter holes by the unmolten raw materials, and improving the working reliability of the extruder.

[0021] Example 2, as Figures 1 to 9As shown in the figure, on the basis of Embodiment 1, it further includes an auxiliary material tank 20, a piston cylinder 21, an arc plate 22, a lever 23, a torsion spring 24, a push rod mechanism 25, a piston plate 26 and a push block 27. The auxiliary material tank 20 is installed on the extruder main body 1. An auxiliary material storage chamber is arranged inside the auxiliary material tank 20. The piston cylinder 21 is installed at the bottom of the auxiliary material storage chamber of the auxiliary material tank 20. A long strip opening is arranged at the upper part of the piston cylinder 21. An auxiliary material output pipe is arranged at the left end of the piston cylinder 21. The auxiliary material output pipe is connected to the auxiliary material interface of the annular sleeve 16. The arc plate 22 is rotatably installed on the outer wall of the upper part of the piston cylinder 21. The left end of the arc plate 22 is rotatably connected to the left end of the piston cylinder 21 through a rotating shaft. The two ends of the torsion spring 24 are respectively connected to the arc plate 22 and the piston cylinder 21. The torsion of the torsion spring 24 makes the arc plate 22 close the long strip opening of the piston cylinder 21. A lever 23 is arranged at the right end of the arc plate 22. The lever 23 extends into the inside of the right end of the piston cylinder 21. The push rod mechanism 25 is installed on the outer wall of the auxiliary material tank 20. The piston rod of the push rod mechanism 25 extends into the piston cylinder 21 from the right end. The piston plate 26 is installed at the end of the piston rod of the push rod mechanism 25. The lever 23 is rotatably connected to the piston rod of the push rod mechanism 25. A push block 27 is installed on the right side wall of the piston plate 26. An inclined guiding surface is arranged on the push block 27. The guiding surface of the push block 27 faces the lever 23.

[0022] Solid auxiliary material particles are stored in the auxiliary material storage chamber of the auxiliary material tank 20. The piston rod of the push rod mechanism 25 reciprocates to contract to the right and then extend to the left. When the piston rod of the push rod mechanism 25 contracts to the right, it drives the piston plate 26 to move to the right in the piston cylinder 21. When the piston plate 26 reaches the right end of the piston cylinder 21, the guiding surface of the push block 27 starts to squeeze the lever 23, thereby driving the lever 23 to rotate around the piston rod of the push rod mechanism 25. The lever 23 drives the arc plate 22 to rotate to one side of the piston cylinder 21 to open the long strip opening, so that the auxiliary material particles enter the piston cylinder 21. At this time, the piston rod of the push rod mechanism 25 extends to the left, the piston plate 26 drives the push block 27 to move to the left. After the push block 27 disengages from the lever 23, the arc plate 22 closes the long strip opening of the piston cylinder 21 under the action of the torsion of the torsion spring 24. At this time, the piston plate 26 continues to move to the left to push the auxiliary material particles in the piston cylinder 21 to the left and send them into the auxiliary material channel of the annular sleeve 16 through the auxiliary material output pipe. Repeating the above actions realizes the continuous feeding of the auxiliary material particles.

[0023] It also includes an annular sleeve 16 and a plurality of inserts 17, the annular sleeve 16 is sleeved on the outer wall of the discharge port of the extruder body 1, an annular auxiliary material channel is arranged inside the annular sleeve 16, an auxiliary material interface connected to the auxiliary material channel is arranged on the annular sleeve 16, a plurality of inserts 17 are uniformly inserted on the outer wall of the discharge port of the extruder body 1, the inner ends of the plurality of inserts 17 are all provided with auxiliary material outlets, the auxiliary material outlets are all located in the discharge port of the extruder body 1, the outer ends of the plurality of inserts 17 are all provided with auxiliary material inlets, the auxiliary material inlets are all located in the auxiliary material channel of the annular sleeve 16; it also includes a track ring 18 and a drive shaft 19, a plurality of inserts The outer ends of 17 all extend out of the outer wall of the annular sleeve 16, and the plurality of insert tubes 17 are all slidably plug-in connected with the annular sleeve 16 and the outer wall of the discharge port of the extruder body 1, and the orbital ring 18 is concentrically arranged on the annular sleeve 16, and the interior of the orbital ring 18 is a track that is not concentric with the annular sleeve 16. The outer ends of the plurality of insert tubes 17 are evenly slidably connected with the track of the orbital ring 18, and a gear ring is arranged on the outer wall of the orbital ring 18. The drive shaft 19 is rotatably installed on the outer wall of the extruder body 1, and one end of the drive shaft 19 is connected to the screw feeder 9 through a transmission pair, and the other end of the drive shaft 19 is meshed with the gear ring of the orbital ring 18 through a gear.

[0024] Auxiliary materials such as insulating gas, such as carbon dioxide, or foaming materials, such as bicarbonate, azodicarbonamide, or elastic vacuum spheres, or volatile insulating polymer particles, etc., are input into the auxiliary material channel of the annular sleeve 16 through the auxiliary material interface, and the auxiliary materials enter into the multiple inserts 17 through the auxiliary material inlet, and then are distributed into the molten raw material through the auxiliary material outlets of the multiple inserts 17. The gas auxiliary material is wrapped by the raw material to directly form insulating bubbles, the foaming material is heated and expanded to form insulating bubbles, the hollow sphere is wrapped by the raw material to directly form vacuum insulating bubbles, and the volatile insulating The insulating polymer particles are vaporized and expanded by heat, and after the polypropylene insulating layer is cooled, vacuum insulating bubbles are formed. The insulating polymer particles are solidified on the inner wall of the vacuum insulating bubble, so as to achieve the purpose of distributing insulating bubbles in the insulating layer of the cable, and improve flexibility and lightness on the basis of ensuring insulation performance; when the auxiliary material is an elastic vacuum sphere or volatile insulating polymer particles, the insulating bubbles in the insulating layer are vacuum insulating bubbles. When the cable is bent, the vacuum insulating bubbles are squeezed. Since there is no gas inside, they will not be squeezed and broken from the inside to the outside by the gas, thereby reducing cracks inside the insulating layer and improving quality; The track of the track ring 18 can be a non-concentric circle such as an eccentric circle, cam shape, elliptical or sawtooth shape of the annular sleeve 16. When the screw feeder 29 rotates, the drive shaft 19 is driven to rotate through the transmission pair, and the drive shaft 19 drives the track ring 18 to rotate through the gear meshing ring gear. The track of the track ring 18 drives multiple plugs 17 to reciprocate along the radial direction of the annular sleeve 16, so that the multiple plugs 17 can transport the auxiliary materials to different positions in the discharge port of the extruder body 1, so that the auxiliary materials are distributed more evenly.

[0025] Example 3Figures 1 to 4 , Figures 10 to 12 As shown, on the basis of Embodiment 1, it further includes a guiding sleeve 28, a plurality of balls 29, a plurality of pulleys 30, a worm wheel disc 31, a second motor 32 and a worm 33. The guiding sleeve 28 is rotatably installed on the conductor core input port of the extrusion head 3. A plurality of balls 29 are circumferentially and rotatably installed on the inner wall of the guiding sleeve 28. The plurality of balls 29 are respectively in rolling contact with two adjacent metal wires in the conductor core. A plurality of pulleys 30 are circumferentially and rotatably installed on the inner wall of the track ring 18. The plurality of pulleys 30 are respectively in rolling contact with the outer walls of multiple metal wires in the conductor core. The worm wheel disc 31 is concentrically installed on the outer wall of the guiding sleeve 28. The second motor 32 is installed on the extrusion head 3. The output shaft of the second motor 32 is concentrically installed with the worm 33. The worm 33 meshes with the worm wheel disc 31; it further includes a bearing seat 34, a second gear ring 35, a third motor 36, a third gear 37, a first turntable 38, two first pressing rollers 39, a second turntable 40 and two second pressing rollers 41. The bearing seat 34 is rotatably installed on the cable outlet of the extrusion head 3. The second gear ring 35 is concentrically installed on the outer wall of the bearing seat 34. The third motor 36 is installed on the extrusion head 3. The output shaft of the third motor 36 is concentrically installed with the third gear 37. The third gear 37 meshes with the second gear ring 35. The first turntable 38 is installed on the bearing seat 34. A first cable channel is provided in the middle of the first turntable 38. Two first pressing rollers 39 are rotatably installed opposite to each other on both sides of the first cable channel. The second turntable 40 is installed on the first turntable 38. A second cable channel is provided in the middle of the second turntable 40. Two second pressing rollers 41 are rotatably installed opposite to each other on both sides of the second cable channel. The two first pressing rollers 39 and the two second pressing rollers 41 are vertically arranged; it further includes a grinding machine 42 and a cold air blower 43. The grinding machine 42 is installed on the first turntable 38. The grinding machine 42 is used to remove the burrs on the outer wall of the cable insulation layer. The cold air blower 43 is installed on the second turntable 40. The cold air blower 43 blows air on the cable to cool the cable insulation layer.

[0026] After passing through the guiding sleeve 28, the conductor core enters the extrusion head 3. The plurality of balls 29 are respectively arranged between two adjacent metal wires of the conductor core, so that the plurality of balls 29 perform rolling limit on the outer walls of the multiple metal wires. At the same time, the plurality of pulleys 30 are respectively arranged on the outer sides of the multiple metal wires of the conductor core and are respectively in rolling contact with the multiple metal wires, thereby performing rolling limit on the multiple metal wires and improving the stability of the conductor core. The second motor 32 drives the worm 33 to rotate. The worm 33 meshes with the worm wheel disc 31 to drive the guiding sleeve 28 to rotate, which can adjust the angles of the plurality of balls 29 and the plurality of pulleys 30 and make the plurality of balls 29 and the plurality of pulleys 30 rotate to adapt to the metal wires arranged side by side or wound. The cable wrapped with an insulating layer is output from the extrusion head 3 through the cable outlet and passes through the first cable channel of the first turntable 38 and the second cable channel of the second turntable 40. The two first pressure rollers 39 and the two second pressure rollers 41 respectively roll and contact the outer walls of the four sides of the cable. The third motor 36 drives the third gear 37 to rotate. The third gear 37 meshes with the second gear ring 35 to drive the bearing seat 34 to rotate. The bearing seat 34 drives the first turntable 38 and the second turntable 40 to rotate. The first turntable 38 drives the two first pressure rollers 39 to rotate around the cable, and the second turntable 40 drives the two second pressure rollers 41 to rotate around the cable, so that the two first pressure rollers 39 and the two second pressure rollers 41 roll and shape the outer surface of the insulating layer of the cable to improve the quality of the insulating layer; The grinding machine 42 rotates with the first turntable 38, and the grinding cutter head of the grinding machine 42 grinds and removes the burrs on the outer wall of the insulating layer of the cable to improve the smoothness of the outer surface of the cable. The cold air blower 43 operates to blow air on the cable, which is beneficial to reducing the temperature of the cable and enabling the insulating layer of the cable to be quickly shaped.

[0027] As Figures 1 to 12 shown, in a polypropylene insulated cable extruder of the present invention, during operation, first, the conductor core passes through the channel of the extrusion head 3, and the polypropylene raw material enters the melting chamber of the extruder main body 1 through the feeding hole. Then, the extrusion motor 2 drives the first screw feeder 6 and the second screw feeder 9 to rotate. The first section of the first screw blade of the first screw feeder 6 pushes the raw material towards the discharge port, and the raw material is heated and melted during the transportation process. The filter plate 7 filters the raw material. The qualified melted raw material is pushed towards the discharge port by the second section of the first screw blade of the first screw feeder 6 after passing through the filter holes of the filter plate 7. The annular sleeve 16 and the multiple inserting pipes 17 add auxiliary material particles into the molten raw material, and the auxiliary material particles form insulating bubbles under the action of the high temperature of the raw material. Then, the mixed material enters the extrusion head 3 and wraps around the outer part of the conductor core to form a cable. After the cable is output from the extrusion head 3 and undergoes the rolling and shaping by the first pressure rollers 39 and the second pressure rollers 41 and the burr removal by the grinding machine 42, it is rolled and shaped again by the two crawler mechanisms 5 and conveyed to the next working station backward. At the same time, the cooling water tank and the spraying mechanism on the auxiliary machine 4 of the extruder cool down the cable; finally, during this process, the unmolten qualified raw material particles intercepted by the filter plate 7 move from the filter plate 7 to the bottom of the melting chamber of the extruder main body 1 under the scraping and guiding action of the multiple scraping plates 10 and enter the reflux channel 8 through the inlet. The rotating second screw feeder 9 conveys the mixed material of the unmolten raw material and the melted raw material in the reflux channel 8 in the reverse direction and enables the mixed material to return to the melting chamber of the extruder main body 1 through the outlet of the reflux channel 8 to be heated and melted again.

[0028] The main functions achieved by the present invention are: 1. Separately carry out the transportation of the molten raw material and the reflux of the unmelted raw material to avoid hindering the transportation of the raw material and improve the reliability of the extruder; 2. Double-station uninterrupted feeding can improve work efficiency, reduce impurity pollution in the air, and improve the quality of the cable insulation layer; 3. It can add auxiliary material particles, and different insulation effects can be achieved through the auxiliary materials; 4. It can limit and support the conductor core of the cable to improve stability; 5. It can shape the insulation layer, remove burrs, and cool it down.

[0029] For the polypropylene insulated cable extruder of the present invention, its installation method, connection method or setting method are all common mechanical methods, and any method that can achieve its beneficial effects can be implemented; the polypropylene insulated cable extruder of the present invention separates the transportation of the molten raw material and the reflux of the unmolten raw material to avoid obstruction to the raw material transportation and improve the reliability of the extruder. It is purchased on the market, and technicians in this industry only need to install and operate it according to the attached instruction manual, without the need for technicians in this field to perform creative labor.

[0030] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A polypropylene-insulated cable extruder, comprising an extruder main body (1), an extrusion motor (2), an extrusion head (3), an extruder auxiliary machine (4) and two track mechanisms (5). A heater is installed on the extruder main body (1). A melting material chamber is arranged inside the extruder main body (1). A feeding port communicating with the melting material chamber is arranged at one end of the extruder main body (1) close to the extrusion motor (2). A discharge port communicating with the melting material chamber is arranged at the other end of the extruder main body (1). The extrusion head (3) is installed on the discharge port of the extruder main body (1). The extruder auxiliary machine (4) is located outside the output end of the extrusion head (3). Two track mechanisms (5) are oppositely installed on the extruder auxiliary machine (4). The two track mechanisms (5) are used for cooling and conveying the cable; characterized in that, It also includes a first screw feeder (6), a filter plate (7), a reflux channel (8) and a second screw feeder (9). The first screw feeder (6) is rotatably installed in the melting chamber of the extruder body (1). The output shaft of the extrusion motor (2) is in transmission connection with the first screw feeder (6). Two sections of first screw vanes are arranged on the outer wall of the first screw feeder (6). The filter plate (7) is installed in the middle and rear part of the melting chamber of the extruder body (1). The two ends of the first screw vanes of the first screw feeder (6) are respectively located on both sides of the filter plate (7). The reflux channel (8) is installed at the bottom of the extruder body (1). The inlet of the reflux channel (8) is located below the filter plate (7). The outlet of the reflux channel (8) is located at one end of the extruder body (1) close to the extrusion motor (2). The second screw feeder (9) is rotatably installed in the reflux channel (8). Second screw vanes are arranged on the outer wall of the second screw feeder (9). The second screw feeder (9) is in transmission connection with the output shaft of the extrusion motor (2) through a transmission assembly.

2. The polypropylene insulated cable extruder according to claim 1, characterized in that It also includes a plurality of scraping plates (10). The plurality of scraping plates (10) are evenly installed on the outer wall of the first screw feeder (6) in a circumferential manner. The plurality of scraping plates (10) all scrape the side of the filter plate (7) facing the extrusion motor (2). The outer ends of the plurality of scraping plates (10) all scrape the inner wall of the extruder body (1).

3. The polypropylene insulated cable extruder according to claim 1, characterized in that, It also includes two hoppers (11), a three-way valve (12) and two cover plates (13). Both of the two hoppers (11) are provided with a storage chamber. Both of the two hoppers (11) are provided with an upper feeding port communicating with the discharge chamber. Both of the two hoppers (11) are provided with a lower discharge port communicating with the discharge chamber. The lower discharge ports of the two hoppers (11) are respectively communicated with the first channel and the second channel of the three-way valve (12). The third channel of the three-way valve (12) is communicated with the feeding port of the extruder body (1). The two cover plates (13) are respectively installed in the storage chambers of the two hoppers (11) in a liftable and slidable manner through the two upper feeding ports. A sliding seal is arranged between the edges of the two cover plates (13) and the inner walls of the storage chambers of the two hoppers (11).

4. The polypropylene insulated cable extruder according to claim 1, wherein, It also includes an air extraction pipe (14) and a heat-resistant diaphragm (15). The air extraction pipe (14) is installed on the top of the extruder body (1). The lower end of the air extraction pipe (14) is communicated with the melting chamber of the extruder body (1). The heat-resistant diaphragm (15) is installed inside the air extraction pipe (14). A joint is arranged at the upper end of the air extraction pipe (14).

5. The polypropylene insulated cable extruder according to claim 1, characterized in that, It also includes an annular sleeve (16) and a plurality of insertion pipes (17). The annular sleeve (16) is sleeved on the outer wall of the discharge port of the extruder body (1). An annular auxiliary material channel is arranged inside the annular sleeve (16). An auxiliary material interface communicated with the auxiliary material channel is arranged on the annular sleeve (16). The plurality of insertion pipes (17) are evenly inserted on the outer wall of the discharge port of the extruder body (1) in a circumferential manner. The inner ends of the plurality of insertion pipes (17) are all provided with auxiliary material outlets, and the auxiliary material outlets are all located inside the discharge port of the extruder body (1). The outer ends of the plurality of insertion pipes (17) are all provided with auxiliary material inlets, and the auxiliary material inlets are all located in the auxiliary material channel of the annular sleeve (16).

6. The polypropylene insulated cable extruder according to claim 5, characterized in that, It further includes an orbital ring (18) and a drive shaft (19). The outer ends of multiple cannulas (17) all extend out of the outer wall of the annular sleeve (16). Multiple cannulas (17) are all slidably inserted and connected to the annular sleeve (16) and the outer wall of the discharge port of the extruder body (1). The orbital ring (18) is concentrically arranged around the annular sleeve (16). The inside of the orbital ring (18) is an orbit that is not concentric with the annular sleeve (16). The outer ends of multiple cannulas (17) are all slidably connected to the orbit of the orbital ring (18). A toothed ring is arranged on the outer wall of the orbital ring (18). The drive shaft (19) is rotatably installed on the outer wall of the extruder body (1). One end of the drive shaft (19) is drivingly connected to the second screw feeder (9) through a transmission pair. The other end of the drive shaft (19) is meshed with the toothed ring of the orbital ring (18) through a gear.

7. The polypropylene insulated cable extruder according to claim 5, characterized in that, It further includes an auxiliary material tank (20), a piston cylinder (21), an arc plate (22), a lever (23), a torsion spring (24), a push rod mechanism (25), a piston plate (26) and a push block (27). The auxiliary material tank (20) is installed on the extruder body (1). An auxiliary material storage chamber is arranged inside the auxiliary material tank (20). The piston cylinder (21) is installed at the bottom of the auxiliary material storage chamber of the auxiliary material tank (20). A long strip opening is arranged at the upper part of the piston cylinder (21). An auxiliary material output pipe is arranged at the left end of the piston cylinder (21). The auxiliary material output pipe is connected to the auxiliary material interface of the annular sleeve (16). The arc plate (22) is rotatably installed on the outer wall at the upper part of the piston cylinder (21). The left end of the arc plate (22) is rotatably connected to the left end of the piston cylinder (21) through a rotating shaft. The two ends of the torsion spring (24) are respectively connected to the arc plate (22) and the piston cylinder (21). The torsion force of the torsion spring (24) makes the arc plate (22) close the long strip opening of the piston cylinder (21). A lever (23) is arranged at the right end of the arc plate (22). The lever (23) extends into the inside of the right end of the piston cylinder (21). The push rod mechanism (25) is installed on the outer wall of the auxiliary material tank (20). The piston rod of the push rod mechanism (25) extends into the piston cylinder (21) from the right end. The piston plate (26) is installed at the end of the piston rod of the push rod mechanism (25). The lever (23) is rotatably connected to the piston rod of the push rod mechanism (25). A push block (27) is installed on the right side wall of the piston plate (26). An inclined guiding surface is arranged on the push block (27). The guiding surface of the push block (27) faces the lever (23).

8. The polypropylene insulated cable extruder according to claim 1, wherein, It further includes a guiding sleeve (28), a plurality of balls (29), a plurality of pulleys (30), a worm wheel disc (31), a second motor (32) and a worm (33). The guiding sleeve (28) is rotatably mounted on the conductor core input port of the extrusion head (3). A plurality of balls (29) are circumferentially and rotatably mounted on the inner wall of the guiding sleeve (28). The plurality of balls (29) are respectively in rolling contact with two adjacent metal wires in the conductor core. A plurality of pulleys (30) are circumferentially and rotatably mounted on the inner wall of the track ring (18). The plurality of pulleys (30) are respectively in rolling contact with the outer walls of multiple metal wires in the conductor core. The worm wheel disc (31) is concentrically mounted on the outer wall of the guiding sleeve (28). The second motor (32) is mounted on the extrusion head (3). The output shaft of the second motor (32) is concentrically mounted with the worm (33). The worm (33) meshes with the worm wheel disc (31).

9. The polypropylene insulated cable extruder according to claim 8, characterized in that, It further includes a bearing seat (34), a second gear ring (35), a third motor (36), a third gear (37), a first turntable (38), two first pressure rollers (39), a second turntable (40) and two second pressure rollers (41). The bearing seat (34) is rotatably mounted on the cable outlet of the extrusion head (3). The second gear ring (35) is concentrically mounted on the outer wall of the bearing seat (34). The third motor (36) is mounted on the extrusion head (3). The output shaft of the third motor (36) is concentrically mounted with the third gear (37). The third gear (37) meshes with the second gear ring (35). The first turntable (38) is mounted on the bearing seat (34). A first cable channel is provided in the middle of the first turntable (38). Two first pressure rollers (39) are rotatably mounted opposite to each other on both sides of the first cable channel. The second turntable (40) is mounted on the first turntable (38). A second cable channel is provided in the middle of the second turntable (40). Two second pressure rollers (41) are rotatably mounted opposite to each other on both sides of the second cable channel. The two first pressure rollers (39) and the two second pressure rollers (41) are vertically arranged.

10. A polypropylene insulated cable extruder according to claim 9, characterized in that, It further includes a grinding machine (42) and a cold air blower (43). The grinding machine (42) is mounted on the first turntable (38). The grinding machine (42) is used to remove the burrs on the outer wall of the cable insulation layer. The cold air blower (43) is mounted on the second turntable (40). The cold air blower (43) blows air to the cable to cool the cable insulation layer.

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