Extrusion molding device and method based on plastic hollow pipe production

Abstract

The invention discloses an extrusion molding device and method based on plastic hollow pipe production, and relates to the technical field of plastic molding, an external cooling system is installed on the outer side of a machine body, the external cooling system is arranged on an extrusion path of a plastic pipe and is provided with a spray head facing the axis position of an extruder, and the spray head sprays and cools the plastic pipe; the internal cooling system is mounted on the outer side of the extruder and extends into the injection molding cavity, and the internal cooling system penetrates through the middle of the mold from the injection molding cavity; the rotating assembly is installed on the outer side of the external cooling system, the rotating assembly makes contact with the plastic pipe and rotates in the circumferential direction with the axis of the plastic pipe as the center, the rotating assembly is provided with flexible scrapers which are arranged on the outer side of the plastic pipe in a circumferential array mode, and the flexible scrapers rotate to scrape water drops on the outer wall of the plastic pipe. In the extrusion molding process of the plastic hollow pipe, the interior and the exterior of the plastic hollow pipe can be synchronously cooled at the same time, and the extrusion molding efficiency of the plastic hollow pipe is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of plastic molding, in particular to an extrusion molding device and method based on the production of plastic hollow tubes. Background Art

[0002] In the extrusion process of plastic tubes, the plastic material needs to be heated to a molten state. Different types of plastics have different melting temperatures. When the plastic material reaches the melting temperature, it becomes soft and can be extruded into the desired tubular shape through the die of the extruder.

[0003] Announcement No. CN117183279B discloses a plastic tube forming device and a forming method thereof. The plastic tube forming device and the forming method thereof, through the setting of the cooling component, can be sleeved on the outer side of the corresponding internal cooling tube after the formed workpiece body enters the cooling rack. With the filling of the coolant, the inner and outer sides of the workpiece body can be cooled, thereby ensuring the cooling uniformity. At the same time, after the workpiece body is cut, the internal cooling tube and the formed workpiece can be turned over by the rotation of the rotating disc rack, which is convenient for the transportation of the workpiece body and ensures the cooling efficiency of the equipment. By reducing the temperature difference between the inside and outside of the workpiece body during cooling, the forming effect of the workpiece body is improved.

[0004] The inside and outside of the plastic pipe are cooled synchronously to make the cooling of the plastic pipe more uniform, avoid excessive temperature difference between the inside and the outside, and reduce the risk of stress concentration and deformation; maintain the dimensional stability of the plastic pipe, reduce problems such as uneven wall thickness, distortion or bending caused by uneven cooling, and improve the overall accuracy and consistency of the product; accelerate the cooling process of the plastic pipe, shorten the production cycle, and improve production efficiency; reduce surface defects such as cooling marks, dents and ripples, and improve the surface finish of the finished product.

[0005] Due to the closed-loop shape of the plastic tube and the length of the plastic extrusion, the process of simultaneously heating the inside and outside of the plastic tube is relatively complicated. As shown in the above patent, a technical solution is provided that can simultaneously cool the inside and outside of the plastic tube, extending from one end of the plastic tube to the inside of the plastic tube to cool the plastic tube. However, the length of the entire plastic tube is limited. The plastic tube needs to be cut into sections during extrusion, which is limited by the internal cooling tube. Therefore, the existing method of synchronous cooling of the inside and outside has a great restriction on the production of plastic tubes. To this end, the present invention proposes an extrusion molding device based on the production of plastic hollow tubes. Summary of the invention

[0006] One of the purposes of the present invention is to provide an extrusion molding device and method based on the production of plastic hollow tubes, which is used for the extrusion molding of plastic hollow tubes, synchronously cools the inside and outside of the plastic tube, and does not limit the extrusion length of the plastic tube.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: an extrusion molding device based on the production of plastic hollow tubes, the extrusion molding device includes a body, the body is placed on the ground, an extruder including an extrusion chamber is arranged on the upper part, a detachable and replaceable mold is installed at the discharge port of the extruder, and the mold corresponds to plastic tubes of different sizes and specifications;

[0008] The extrusion molding device also includes:

[0009] An external cooling system is installed outside the machine body. The external cooling system is arranged on the extrusion path of the plastic pipe and is equipped with a nozzle facing the axis of the extruder. The nozzle sprays the plastic pipe to cool it down. A water tank is arranged under the machine body corresponding to the nozzle. The water tank is connected with the external cooling system to form a circulation.

[0010] The internal cooling system is installed outside the extruder and extends to the inside of the injection cavity. The internal cooling system passes through the middle of the mold from the injection cavity. During the extrusion process of the plastic tube, the internal cooling system is located inside the plastic tube to cool the plastic tube. The cooling position of the internal cooling system corresponds to the cooling position of the external cooling system.

[0011] The rotating component is installed outside the external cooling system. The rotating component contacts the plastic pipe and rotates circumferentially with the axis of the plastic pipe as the center. The rotating component is equipped with a circumferential array of flexible scrapers arranged outside the plastic pipe. The flexible scrapers rotate to scrape off water droplets on the outer wall of the plastic pipe.

[0012] In one or more embodiments of the present invention, the water tank is arranged along the extrusion direction of the extruder, and the spray range of the nozzle of the external cooling system of the water tank is as follows:

[0013] A positioning frame is located outside the machine body, the top of the positioning frame supports the annular connector, a mounting tube is rotatably arranged inside the annular connector, the mounting tube can rotate relative to the annular connector, and the nozzle is arranged at one end of the mounting tube;

[0014] The nozzle is set at an angle, and the reaction force pushes the installation pipe to rotate during the nozzle spraying process.

[0015] In one or more embodiments of the present invention, the external cooling system comprises:

[0016] The guide groove is provided on the outside of the machine body, a guide rail is arranged on the outside of the guide groove, the guide rail is embedded in the guide groove and slides inside the guide groove, and the positioning frame is detachably installed on the outside of the guide rail;

[0017] The circulating water tank is installed on the outside of the guide rail. A cooler is arranged on the outside of the circulating water tank to cool the circulating water.

[0018] The tank body can be slidably installed inside the machine body, the tank body is connected to the water tank, and the tank body is connected to the cooler through a hose, and the cooling water in the water tank enters the circulating water tank through the hose;

[0019] The first circulating pump is installed outside the first circulating water tank and extends into the first circulating water tank to extract cooling water from the circulating water tank. A connecting pipe is arranged between the first circulating pump and the connecting head for communication between the two.

[0020] In one or more embodiments of the present invention, the internal cooling system comprises:

[0021] A double-layer circulation pipeline is installed inside the extruder. The inner layer of the double-layer circulation pipeline conveys circulating water, and the outer layer conveys circulating medium. At least four partitions are arranged inside the outer layer to divide the outer layer into four outer cavities. The four outer cavities form two circulation cavities. The circulating medium circulates inside the two circulation cavities.

[0022] The cooling water circulation system and the medium circulation system are installed on one side of the extruder, and the cooling water circulation system and the medium circulation system have the same structure. The cooling water circulation system is connected to the inner layer, and the medium circulation system is connected to the outer layer.

[0023] In one or more embodiments of the present invention, the cooling water circulation system and / or the medium circulation system comprises:

[0024] A cooler is installed outside the extruder or the machine body, and is used to cool the circulating medium or cooling water. A liquid storage tank is arranged outside the cooler and is connected to the liquid storage tank. A second circulating pump is arranged outside the liquid storage tank.

[0025] A connector is arranged at one end of the double-layer circulation pipeline close to the second circulation pump, and the second circulation pump is connected to the double-layer circulation pipeline through the connector;

[0026] The connector connected to the medium circulation system is provided with two liquid inlet pipes and liquid outlet pipes corresponding to the two circulation chambers. The liquid inlet pipe is connected to the second circulation pump, and the liquid outlet pipe is connected to the cooler.

[0027] In one or more embodiments of the present invention, the internal circulation system further comprises:

[0028] Extension pipe, the extension pipe is connected with the double-layer circulation pipeline, and the extension pipe is installed on the outside of the extruder through a nut. The extension pipe is arranged in two sections, one section connected with the double-layer circulation pipeline is a double-layer arrangement, and the other section is a single-layer arrangement. The double-layer section of the extension pipe has the same structure as the double-layer circulation pipeline;

[0029] A pressing plate is arranged at one end where the double-layer circulation pipeline is connected with the extension pipe. The pressing plate is used to seal the outer layer of the double-layer circulation pipeline. After the extension pipe is connected with the double-layer circulation pipeline, the pressing plate is pressed. After the pressing plate is pressed, the double-layer circulation pipeline is connected with the extension pipe.

[0030] The spray hole is formed at one end of the extension pipe extending outward, and cooling water is sprayed from the spray hole to the inner wall of the plastic pipe.

[0031] In one or more embodiments of the present invention, the rotating assembly includes:

[0032] A connecting frame is installed on the outside of the positioning frame, a rotating frame that can rotate relative to the connecting frame is arranged on the inside of the connecting frame, a flexible scraper is installed on the inside of the rotating frame, and a groove is provided on the side of the flexible scraper that contacts the outer wall of the plastic pipe;

[0033] The flexible scraper is spirally arranged, and the side of the flexible scraper close to the positioning frame is inclined, and the inner dimension of one end of the flexible scraper close to the positioning frame is larger than the inner dimension of the other end of the flexible scraper.

[0034] In one or more embodiments of the present invention, the rotating assembly further comprises:

[0035] The mounting table is installed on the outside of the positioning frame and the connecting frame, and a roller is arranged inside the mounting frame, and the middle part of the roller is concave inward and can contact the plastic pipe;

[0036] The transmission assembly is installed on the inner side of the mounting platform. The roller and the rotating frame are both connected to the transmission assembly. The rotation of the roller drives the rotating frame to rotate through the transmission assembly.

[0037] The embodiment of the present invention further provides a molding method of an extrusion molding device, which is used for the above-mentioned extrusion molding device, and comprises the following steps:

[0038] Install the mold according to the specifications of the plastic pipe to be produced and connect the internal cooling system to the extruder;

[0039] When the extruder is working, the internal cooling system sends cooling water into the plastic pipe to cool the inner wall of the plastic pipe;

[0040] The external cooling system sprays cooling water on the outside of the plastic pipe through a nozzle to cool the outer wall of the plastic pipe;

[0041] The movement of the plastic pipe drives the rotating assembly to rotate. During the rotation of the rotating assembly, the flexible scraper contacts the plastic pipe to remove water drops on the outer wall of the plastic pipe.

[0042] In one or more embodiments of the present invention, a portion of the internal cooling system is removable, and after the portion of the structure of the internal cooling system is removed, the inner wall of the plastic pipe is cooled from the extrusion position of the mold.

[0043] Through the above technical solution, the present invention has the following beneficial effects:

[0044] 1. In the process of extruding the hollow plastic tube, the present invention can simultaneously cool the inside and outside of the hollow plastic tube to ensure the extrusion efficiency of the hollow plastic tube. Since the internal cooling system extends from the inside of the extruder to the inside of the hollow plastic tube, the extrusion length of the hollow plastic tube is not limited during the extrusion process.

[0045] 2. The setting of the internal cooling system extends from the injection molding machine to the inside of the plastic pipe, and the plastic pipe is cooled from the inside of the plastic pipe. The internal cooling system is equipped with two cooling states. It can be extended to the cooling position synchronized with the external cooling system for synchronous cooling, and can also cool the plastic pipe from the extrusion position of the mold. The cooling state is switched according to the usage status.

[0046] 3. The external cooling system is set to a sliding state, and the nozzle cooling position corresponding to the nozzle is adjusted according to the specifications of the plastic pipe. The nozzle is set to be rotatable to increase the corresponding spray range of the nozzle, so that the plastic pipe can be cooled more evenly and the cooling effect of the plastic pipe is guaranteed.

[0047] 4. A flexible scraper capable of stably contacting the plastic pipe is provided. During the transportation of the plastic pipe, the flexible scraper is driven to rotate through the transmission component. The flexible scraper is used to scrape off water droplets on the surface of the plastic pipe. The threaded setting of the flexible scraper can enable a single flexible scraper to correspond to a larger plastic pipe surface range.

[0048] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A perspective view of the present invention;

[0050] Figure 2 It is a schematic diagram of removing the rotating assembly of the present invention;

[0051] Figure 3 It is a schematic diagram of an extruder of the present invention;

[0052] Figure 4 It is a partial cross-sectional view of the extruder of the present invention;

[0053] Figure 5 Schematic diagram of the internal cooling system of the present invention Figure 1 ;

[0054] Figure 6 Schematic diagram of the internal cooling system of the present invention Figure 2 ;

[0055] Figure 7 It is a partial schematic diagram of the medium circulation system of the present invention;

[0056] Figure 8 It is a partial schematic diagram of the cooling water circulation system of the present invention;

[0057] Fig. 9 It is a schematic diagram of the double-layer circulation pipeline and extension pipe of the present invention;

[0058] Fig.10 It is a schematic diagram of the connection position of the double-layer circulation pipeline and the extension pipe of the present invention;

[0059] Fig.11 It is a plan view of the pressing plate of the present invention;

[0060] Fig.12 The rotating assembly of the present invention is shown in FIG. Figure 1 ;

[0061] Fig.13 The rotating assembly of the present invention is shown in FIG. Figure 2 ;

[0062] Fig.14 A half-section view of a rotating assembly of the present invention;

[0063] Fig.15 Schematic diagram of the external cooling system of the present invention Figure 1 ;

[0064] Fig.16 Schematic diagram of the external cooling system of the present invention Figure 2 ;

[0065] Fig.17 It is a schematic diagram of the position of the connecting pipe of the present invention;

[0066] Fig.18 It is an exploded diagram of the external cooling system of the present invention.

[0067] In the figure: 1 machine body, 2 extruder, 3 mold, 4 external cooling system, 5 internal cooling system, 6 rotating assembly, 7 water tank;

[0068] 41 positioning frame, 42 annular connector, 43 mounting pipe, 44 nozzle, 45 guide groove, 46 guide rail, 47 circulating water tank, 48 tank body, 49 hose, 410 first circulating pump, 411 connecting pipe;

[0069] 51 double-layer circulation pipeline, 52 cooling water circulation system, 53 medium circulation system, 54 cooler, 55 liquid storage tank, 56 second circulation pump, 57 connector, 58 liquid inlet pipe, 59 liquid outlet pipe, 510 extension pipe, 511 pressing plate, 512 spray hole;

[0070] 61 connecting frame, 62 rotating frame, 63 flexible scraper, 64 groove, 65 mounting platform, 66 roller, 67 transmission assembly. DETAILED DESCRIPTION

[0071] The following will disclose multiple embodiments of the present invention with the accompanying drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. In other words, in some embodiments of the present invention, these practical details are not necessary. And if it is possible to implement, the features of different embodiments can be applied interchangeably.

[0072] Unless otherwise defined, all words (including technical and scientific terms) used herein have their usual meanings, which can be understood by those familiar with this field. Furthermore, the definitions of the above words in commonly used dictionaries should be interpreted as the meanings consistent with the relevant fields of the present invention in the content of this specification. Unless otherwise clearly defined, these words will not be interpreted as idealized or overly formal meanings.

[0073] The following explains the relationships and terms used in the present invention:

[0074] Parallelism: The parallelism defined in the present invention is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, which allows for non-absolute parallelism due to factors such as assembly tolerance, design tolerance, and influence of structural flatness. Small angular errors are allowed. For example, an assembly error range of less than 10 degrees can be understood as a parallel relationship.

[0075] Vertical: The verticality defined in the present invention is not limited to an absolute vertical intersection (angle of 90 degrees). It allows for non-absolute vertical intersections caused by factors such as assembly tolerance, design tolerance, and influence of structural flatness. It also allows for errors in a small angle range. For example, the assembly error range of 80 to 100 degrees can be understood as a vertical relationship.

[0076] Ground: The ground defined in the present invention is not limited to a certain material or region, but only a platform for carrying the present invention, and stacking, tilting, and flatness changes are allowed. For example, cement ground, tile ground, work platform, etc. can all be interpreted as ground.

[0077] The above explanation does not completely include the relationship definitions given in the present invention, but only represents a part of the present invention.

[0078] The invention provides an extrusion molding device based on the production of a plastic hollow tube, which can cool the inside and the outside of the plastic tube simultaneously during the extrusion process of the plastic tube without affecting the extrusion length of the plastic tube.

[0079] like Figure 1-2 As shown, in one embodiment, the extrusion molding device includes a body 1, which is placed on the ground, and an extruder 2 including an extrusion chamber is arranged on the upper part thereof, and a detachable and replaceable mold 3 is installed at the discharge port of the extruder 2, and the mold 3 corresponds to plastic pipes of different sizes and specifications;

[0080] The extrusion molding device also includes:

[0081] The external cooling system 4 is installed outside the machine body 1. The external cooling system 4 is arranged on the extrusion path of the plastic pipe and is provided with a nozzle 44 facing the axis of the extruder 2. The nozzle 44 sprays the plastic pipe to cool it down. A water tank 7 is arranged below the machine body 1 corresponding to the nozzle 44. The water tank 7 is connected with the external cooling system 4 to form a circulation.

[0082] The internal cooling system 5 is installed outside the extruder 2 and extends to the inside of the injection cavity. The internal cooling system 5 passes through the middle of the mold 3 from the injection cavity. During the extrusion process of the plastic tube, the internal cooling system 5 is located inside the plastic tube to cool the plastic tube. The cooling position of the internal cooling system 5 corresponds to the cooling position of the external cooling system 4.

[0083] The rotating assembly 6 is installed outside the external cooling system 4. The rotating assembly 6 contacts the plastic pipe and rotates circumferentially around the axis of the plastic pipe. The rotating assembly 6 is equipped with a flexible scraper 63 arranged in a circumferential array outside the plastic pipe. The flexible scraper 63 rotates to scrape off water droplets on the outer wall of the plastic pipe.

[0084] In one feasible method, the external cooling system 4 cooperates with the internal cooling system 5 to cool the plastic tube, and the positions of the external cooling system 4 and the internal cooling system 5 correspond to each other, and one plastic tube is cooled at the same time to ensure the cooling effect of the plastic tube, and the internal cooling system 5 extends from the inside of the injection cavity to the inside of the plastic tube, rather than from the head position of the plastic tube to the inside of the plastic tube, thereby avoiding the problem of internal cooling of the plastic tube limiting the length of a single plastic tube.

[0085] The internal cooling system 5 has two cooling states. Therefore, the internal cooling system 5 is disassembled. The extended part of the internal cooling system 5 is connected to the extruder 2 by a threaded connection. After the extended part is removed, the cooling position of the internal cooling system 5 is located inside the plastic pipe corresponding to the position of the mold 3. After the extended part is connected, the cooling position of the internal cooling system 5 corresponds to the cooling position of the external cooling system 4.

[0086] like Figure 2 as well as Fig.15 As shown, in one embodiment, the water tank 7 is arranged along the extrusion direction of the extruder, and the spray range of the nozzle 44 of the external cooling system 4 of the water tank 7 is sprayed, and the external cooling system 4 includes:

[0087] like Figure 15-18 As shown, the positioning frame 41 is located outside the machine body 1, and the top of the positioning frame 41 supports the annular connector 5742. The mounting tube 43 is rotatably arranged inside the annular connector 5742. The mounting tube 43 can rotate relative to the annular connector 5742, and the nozzle 44 is arranged at one end of the mounting tube 43;

[0088] The nozzle 44 is arranged at an angle, and during the spraying process, the nozzle 44 pushes the mounting tube 43 to rotate through the reaction force.

[0089] In one feasible method, the annular connector 5742 is in a connected state with the mounting tube 43, the annular connector 5742 is supported and limited by the positioning frame 41, the annular connector 5742 cannot rotate, and a reaction force is generated when the nozzle 44 sprays, and the nozzle 44 is arranged at an angle, and the reaction force of the spraying of the nozzle 44 is used to realize the rotation of the mounting tube 43.

[0090] Since the rotation of the mounting tube 43 changes the position of the nozzle 44, multiple positions on the outside of the plastic tube can directly contact the cooling water, thereby ensuring that the heat dissipation on the outside of the plastic tube is more uniform.

[0091] like Figure 16-18 As shown, in one embodiment, the external cooling system 4 includes:

[0092] The guide groove 45 is provided on the outside of the body 1. A guide rail 46 is provided on the outside of the guide groove 45. The guide rail 46 is embedded in the guide groove 45 and slides inside the guide groove 45. The positioning frame 41 is detachably mounted on the outside of the guide rail 46.

[0093] A circulating water tank 47 is installed outside the guide rail 46. A cooler 54 is arranged outside the circulating water tank 47 to cool the circulating water.

[0094] The tank body 48 can be slidably mounted on the inner side of the machine body 1. The tank body 48 is connected to the water tank 7 and is connected to the cooler 54 via a hose 49. The cooling water in the water tank 7 enters the circulating water tank 47 via the hose 49.

[0095] The first circulation pump 410 is installed outside the first circulation water tank 47 and extends into the first circulation water tank 47 to extract cooling water from the circulation water tank 47. A connecting pipe 411 is arranged between the first circulation pump 410 and the connector 57 for communication between the two.

[0096] In this embodiment, a slidable guide rail 46 is configured to adjust the spraying position of the nozzle 44. The length of the guide groove 45 is smaller than the length of the water trough 7. When the guide rail 46 moves to the two ends of the guide groove 45, the cooling water sprayed by the nozzle 44 can always drip into the water trough 7.

[0097] The trough body 48 is connected to the water trough 7, and the cooling water inside the water trough 7 enters the trough body 48 to facilitate the recovery of the cooling water. In order to further improve the recovery effect of the water trough 7, the bottom of the water trough 7 is set to an inclined state, and the trough body 48 is at the lowest point of the water trough 7 and is connected to the water trough 7. Since the position of the trough body 48 is fixed, the setting of the hose 49 can avoid interfering with the movement of the guide rail 46.

[0098] Among them, since the connecting tube 411 is closer to the extruded plastic tube, in order to ensure the service life of the connecting tube 411, the connecting tube 411 is a metal tube, and since the positioning frame 41 follows the position change of the guide rail 46, the connecting tube 411 is a metal tube and does not affect the movement of the guide rail 46.

[0099] In another embodiment, in order to ensure the stability of the guide rail 46, a rotatable positioning head is provided at both ends of the guide rail 46. The positioning head is threadedly installed inside the guide rail 46 and can contact the machine body 1. When the guide rail 46 needs to be positioned, the positioning head rotates to increase the friction between the machine body 1 to ensure the stable position of the guide rail 46.

[0100] like Figure 3-10 As shown, in one embodiment, the internal cooling system 5 includes:

[0101] A double-layer circulation pipeline 51 is installed inside the extruder 2. The inner layer of the double-layer circulation pipeline 51 conveys circulating water, and the outer layer conveys circulating medium. At least four partitions are arranged inside the outer layer to divide the outer layer into four outer cavities. The four outer cavities form two circulation cavities. The circulating medium circulates inside the two circulation cavities.

[0102] The cooling water circulation system 52 and the medium circulation system 53 are installed on one side of the extruder 2, and the cooling water circulation system 52 and the medium circulation system 53 have the same structure. The cooling water circulation system 52 is connected to the inner layer, and the medium circulation system 53 is connected to the outer layer.

[0103] In one feasible method, a double-layer circulation pipeline 51 is set up to ensure the temperature of the cooling water transported in the inner layer through the circulating medium configured on the outer side, so as to avoid excessive temperature increase during the cooling water transportation process, resulting in the cooling water being unable to achieve the expected effect when spraying.

[0104] The outer layer can be circulated to prevent the temperature from being transferred to the inner layer and affecting the temperature of the cooling water through the rapid flow of the circulating medium. The present invention does not limit the specific material of the circulating medium, as long as it has low thermal conductivity. Exemplarily, the circulating medium is a special oil or a coolant.

[0105] like Figure 5-8 As shown, in one embodiment, the cooling water circulation system 52 and / or the medium circulation system 53 includes:

[0106] A cooler 54 is installed outside the extruder 2 or the machine body 1 and is used to cool the circulating medium or cooling water. A liquid storage tank 55 is arranged outside the cooler 54 and is connected to the liquid storage tank 55. A second circulating pump 56 is arranged outside the liquid storage tank 55.

[0107] A connector 57 is provided at one end of the double-layer circulation pipeline 51 close to the second circulation pump 56, and the second circulation pump 56 is connected to the double-layer circulation pipeline 51 through the connector 57;

[0108] The connector 57 connected to the medium circulation system 53 is provided with two liquid inlet pipes 58 and liquid outlet pipes 59 corresponding to the two circulation chambers. The liquid inlet pipe 58 is connected to the second circulation pump 56 , and the liquid outlet pipe 59 is connected to the cooler 54 .

[0109] In one feasible method, providing a connector 57 can make it easier to connect the second circulation pump 56 or the liquid storage tank 55 with the double-layer circulation pipeline 51. The connector 57 is connected to the double-layer circulation pipeline 51 by means of threads or nuts, thereby ensuring the stability of the connection between the connector 57 and the double-layer circulation pipeline 51.

[0110] like Figure 9-11 As shown, in one embodiment, the internal circulation system further comprises:

[0111] Extension pipe 510, the extension pipe 510 is connected to the double-layer circulation pipeline 51, and the extension pipe 510 is installed on the outside of the extruder 2 through a nut. The extension pipe 510 is arranged in two sections, one section connected to the double-layer circulation pipeline 51 is a double-layer arrangement, and the other section is a single-layer arrangement. The double-layer section of the extension pipe 510 has the same structure as the double-layer circulation pipeline 51;

[0112] A pressing plate 511 is provided at one end where the double-layer circulation pipeline 51 is connected to the extension pipe 510. The pressing plate 511 is used to seal the outer layer of the double-layer circulation pipeline 51. After the extension pipe 510 is connected to the double-layer circulation pipeline 51, the pressing plate 511 is pressed. After the pressing plate 511 is pressed, the double-layer circulation pipeline 51 is connected to the extension pipe 510.

[0113] The spray hole 512 is formed at one end of the extension tube 510 extending outward, and cooling water is sprayed from the spray hole 512 to the inner wall of the plastic tube.

[0114] In one feasible method, an extension pipe 510 is provided to be connected to the double-layer circulation pipeline 51, so that the spraying position of the internal cooling water can be set corresponding to the position corresponding to the external cooling system 4 to ensure the cooling position of the external cooling system 4 and the internal cooling system 5, and to perform internal and external synchronous cooling when cooling the plastic pipe.

[0115] The pressure plate 511 is used to control the circulation state of the double-layer circulation pipeline 51.

[0116] Optionally, a section of the extension tube 510 connecting to the double-layer circulation pipeline 51 protrudes outward, and the double-layer circulation pipeline 51 is provided with a depression corresponding to the protrusion. The protrusion and the depression cooperate to limit the rotation of the extension tube 510, so that the extension tube 510 does not rotate relative to the double-layer circulation pipeline 51. After the protrusion is pressed on the extrusion plate 511, the connection state of the two outer cavities is changed to a separation state, and the two cavities are connected through the inside of the extension tube 510.

[0117] like Figure 12-14 As shown, in one embodiment, the rotating assembly 6 includes:

[0118] A connecting frame 61 is installed on the outside of the positioning frame 41. A rotating frame 62 is arranged inside the connecting frame 61 and can rotate relative to the connecting frame 61. A flexible scraper 63 is installed inside the rotating frame 62. A groove 64 is formed on the side of the flexible scraper 63 that contacts the outer wall of the plastic tube.

[0119] The flexible scraper 63 is spirally arranged, and the side of the flexible scraper 63 close to the positioning frame 41 is inclined. The inner dimension of one end of the flexible scraper 63 close to the positioning frame 41 is larger than the inner dimension of the other end of the flexible scraper 63 .

[0120] In one feasible method, the flexible scraper 63 is arranged to fit the plastic tube, and after the flexible scraper 63 is squeezed by the plastic tube, it can be deformed, so that the flexible scraper 63 can stably contact the outer wall of the plastic tube. When the plastic tube is squeezed out, it can stably contact the outer wall of the flexible scraper 63, thereby scraping off water droplets on the outer wall of the plastic tube.

[0121] The flexible scraper 63 is arranged in a spiral shape so that the flexible scraper 63 can contact a wider range of plastic pipes.

[0122] like Figure 12-14 As shown, in one embodiment, the rotating assembly 6 further includes:

[0123] The mounting platform 65 is mounted on the outer sides of the positioning frame 41 and the connecting frame 61. A roller 66 is disposed on the inner side of the mounting frame. The middle part of the roller 66 is concave inwards and can contact the plastic pipe.

[0124] The transmission assembly 67 is installed on the inner side of the mounting platform 65 . The roller 66 and the rotating frame 62 are both in transmission connection with the transmission assembly 67 . The rotation of the roller 66 drives the rotating frame 62 to rotate through the transmission assembly 67 .

[0125] In one practicable manner, the movement of the roller 66 is used to drive the transmission assembly 67, and the transmission assembly 67 is used to drive the rotating frame 62 to rotate, so that the friction force can be used to drive the roller 66 to rotate during the plastic tube extrusion process, and the rotating frame 62 can rotate synchronously when the roller 66 rotates.

[0126] Optionally, the transmission assembly 67 is a crown gear, and teeth are arranged on the outer side of the rotating frame 62 to mesh with the crown gear for transmission, while a gear is arranged on the outer side of the roller 66 to mesh with the crown gear. During the rotation of the roller 66, the gear drives the crown gear to rotate, and the crown gear drives the rotating frame 62 to rotate.

[0127] The embodiment of the present invention further provides a molding method of an extrusion molding device, which is used for the above-mentioned extrusion molding device, and comprises the following steps:

[0128] Install the mold 3 according to the specifications of the plastic pipe to be produced, and connect the internal cooling system 5 to the extruder 2;

[0129] When the extruder 2 is working, the internal cooling system 5 sends cooling water into the plastic pipe to cool the inner wall of the plastic pipe;

[0130] The external cooling system 4 sprays cooling water onto the outside of the plastic pipe through a nozzle 44 to cool the outer wall of the plastic pipe;

[0131] The movement of the plastic pipe drives the rotating assembly 6 to rotate. During the rotation of the rotating assembly 6, the flexible scraper 63 contacts the plastic pipe to remove water drops on the outer wall of the plastic pipe.

[0132] In one embodiment, part of the internal cooling system 5 is removable, and after the part of the structure of the internal cooling system 5 is removed, the inner wall of the plastic pipe is cooled at the extrusion position of the mold.

[0133] Although the present invention is disclosed in conjunction with the above embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the attached claims.

Claims

1. An extrusion molding device based on the production of plastic hollow tubes, the extrusion molding device comprising a body (1), the body (1) is placed on the ground, an extruder (2) including an extrusion chamber is arranged on the upper part of the body, a detachable and replaceable mold (3) is installed at the discharge port of the extruder (2), and the mold (3) corresponds to plastic tubes of different sizes and specifications; characterized in that: The extrusion molding device also includes: An external cooling system (4) is installed outside the machine body (1). The external cooling system (4) is arranged on the extrusion path of the plastic pipe and is provided with a nozzle (44) facing the axis of the extruder (2). The nozzle (44) sprays the plastic pipe to cool it down. A water tank (7) is arranged below the machine body (1) corresponding to the nozzle (44). The water tank (7) is connected to the external cooling system (4) to form a circulation. An internal cooling system (5) is installed outside the extruder (2) and extends into the injection cavity. The internal cooling system (5) passes through the middle of the mold (3) from the injection cavity and is located inside the plastic tube to cool the plastic tube during the extrusion process. The cooling position of the internal cooling system (5) corresponds to the cooling position of the external cooling system (4); The rotating assembly (6) is installed outside the external cooling system (4). The rotating assembly (6) contacts the plastic pipe and rotates circumferentially with the axis of the plastic pipe as the center. The rotating assembly (6) is equipped with a flexible scraper (63) arranged in a circumferential array outside the plastic pipe. The flexible scraper (63) rotates to scrape off water droplets on the outer wall of the plastic pipe.

2. The extrusion molding device based on the production of plastic hollow tubes according to claim 1 is characterized in that: The water tank (7) is arranged along the extrusion direction of the extruder, and the water tank (7) has a spraying range of a nozzle (44) of an external cooling system (4), and the external cooling system (4) includes: A positioning frame (41) is located outside the machine body (1), the top of the positioning frame (41) supports the annular connector (57) (42), a mounting tube (43) is rotatably arranged inside the annular connector (57) (42), the mounting tube (43) is rotatable relative to the annular connector (57) (42), and a spray head (44) is arranged at one end of the mounting tube (43); The spray head (44) is arranged at an angle, and during the spraying process, the spray head (44) pushes the mounting pipe (43) to rotate through the reaction force.

3. An extrusion molding device based on the production of plastic hollow tubes according to claim 2, characterized in that: The external cooling system (4) comprises: A guide groove (45) is provided on the outside of the machine body (1), a guide rail (46) is arranged on the outside of the guide groove (45), the guide rail (46) is embedded in the guide groove (45) and slides inside the guide groove (45), and the positioning frame (41) is detachably mounted on the outside of the guide rail (46); A circulating water tank (47) is installed outside the guide rail (46). A cooler (54) is arranged outside the circulating water tank (47) to cool the circulating water. A tank body (48) is slidably mounted on the inner side of the machine body (1); the tank body (48) is connected to the water tank (7), and the tank body (48) is connected to the cooler (54) via a hose (49); the cooling water in the water tank (7) enters the interior of the circulating water tank (47) via the hose (49); The first circulating pump (410) is installed outside the first circulating water tank (47) and extends into the first circulating water tank (47) to extract cooling water from the circulating water tank (47). A connecting pipe (411) is arranged between the first circulating pump (410) and the connecting head (57) for communication between the two.

4. The extrusion molding device based on the production of plastic hollow tubes according to claim 3 is characterized in that: The internal cooling system (5) comprises: A double-layer circulation pipeline (51) is installed inside the extruder (2), the inner layer of the double-layer circulation pipeline (51) conveys circulating water, and the outer layer conveys circulating medium, at least four partitions are arranged inside the outer layer to divide the outer layer into four outer cavities, the four outer cavities form two circulation cavities, and the circulating medium circulates inside the two circulation cavities; The cooling water circulation system (52) and the medium circulation system (53) are installed on one side of the extruder (2), and the cooling water circulation system (52) and the medium circulation system (53) have the same structure. The cooling water circulation system (52) is connected to the inner layer, and the medium circulation system (53) is connected to the outer layer.

5. The extrusion molding device based on the production of plastic hollow tubes according to claim 4 is characterized in that: The cooling water circulation system (52) and / or the medium circulation system (53) comprises: A cooler (54) is installed on the outside of the extruder (2) or the machine body (1) and is used to cool the circulating medium or cooling water. A liquid storage tank (55) is arranged outside the cooler (54) and is connected to the liquid storage tank (55). A second circulating pump (56) is arranged outside the liquid storage tank (55); A connector (57) is arranged at one end of the double-layer circulation pipeline (51) close to the second circulation pump (56), and the second circulation pump (56) is connected to the double-layer circulation pipeline (51) through the connector (57); The connector (57) connected to the medium circulation system (53) is provided with two liquid inlet pipes (58) and liquid outlet pipes (59) corresponding to the two circulation chambers. The liquid inlet pipe (58) is connected to the second circulation pump (56), and the liquid outlet pipe (59) is connected to the cooler (54).

6. An extrusion molding device based on the production of plastic hollow tubes according to claim 5, characterized in that: The internal circulatory system also includes: An extension pipe (510), the extension pipe (510) is connected to the double-layer circulation pipeline (51), and the extension pipe (510) is installed on the outside of the extruder (2) through a nut. The extension pipe (510) is arranged in two sections, one section connected to the double-layer circulation pipeline (51) is a double-layer arrangement, and the other section is a single-layer arrangement. The double-layer section of the extension pipe (510) has the same structure as the double-layer circulation pipeline (51); A pressing plate (511) is arranged at one end where the double-layer circulation pipeline (51) is connected to the extension pipe (510). The pressing plate (511) is used to seal the outer layer of the double-layer circulation pipeline (51). After the extension pipe (510) is connected to the double-layer circulation pipeline (51), the pressing plate (511) is pressed. After the pressing plate (511) is pressed, the double-layer circulation pipeline (51) and the extension pipe (510) are connected. The spray hole (512) is formed at one end of the extension tube (510) extending outward, and cooling water is sprayed from the spray hole (512) to the inner wall of the plastic tube.

7. An extrusion molding device based on the production of plastic hollow tubes according to claim 6, characterized in that: The rotating assembly (6) comprises: A connecting frame (61) is installed on the outside of the positioning frame (41), a rotating frame (62) is arranged inside the connecting frame (61) and can rotate relative to the connecting frame (61), a flexible scraper (63) is installed on the inside of the rotating frame (62), and a groove (64) is formed on the side of the flexible scraper (63) that contacts the outer wall of the plastic pipe; The flexible scraper (63) is arranged in a spiral shape, and the side of the flexible scraper (63) close to the positioning frame (41) is arranged obliquely, and the inner dimension of one end of the flexible scraper (63) close to the positioning frame (41) is larger than the inner dimension of the other end of the flexible scraper (63).

8. An extrusion molding device based on the production of plastic hollow tubes according to claim 7, characterized in that: The rotating assembly (6) further comprises: The mounting platform (65) is mounted on the outer sides of the positioning frame (41) and the connecting frame (61), and a roller (66) is arranged on the inner side of the mounting frame, wherein the middle part of the roller (66) is recessed inwards and can contact the plastic pipe; The transmission assembly (67) is installed on the inner side of the mounting platform (65). The roller (66) and the rotating frame (62) are both connected to the transmission assembly (67). The rotation of the roller (66) drives the rotating frame (62) to rotate through the transmission assembly (67).

9. A molding method for an extrusion molding device, used for the extrusion molding device according to any one of claims 1 to 9, characterized in that: The following steps are involved: Install the mold (3) according to the specifications of the plastic pipe to be produced, and connect the internal cooling system (5) to the extruder (2); When the extruder (2) is working, the internal cooling system (5) sends cooling water into the plastic pipe to cool the inner wall of the plastic pipe; The external cooling system (4) sprays cooling water onto the outside of the plastic pipe through a nozzle (44) to cool the outer wall of the plastic pipe; The movement of the plastic pipe drives the rotating assembly (6) to rotate. During the rotation of the rotating assembly (6), the flexible scraper (63) contacts the plastic pipe to remove water drops on the outer wall of the plastic pipe.

10. The molding method of the extrusion molding device according to claim 9, characterized in that: The internal cooling system (5) can be partially removed. After the internal cooling system (5) has partially removed, the inner wall of the plastic pipe is cooled from the extrusion position of the mold.

Images