A device and method for sealing the ends of steel wire pipe

Abstract

The application discloses a device and method for sealing of a steel wire pipe end, and belongs to the technical field of steel wire pipe processing. The device comprises a coaxially arranged injection molding die and a heating die, and the heating die can move reciprocally along the axis of the injection molding die. The injection molding die comprises oppositely arranged first and second die bodies, and the first and second die bodies are both provided with cavities. The cavities of the first and second die bodies both comprise, in the axial direction, a first semicircular cavity, a sealing ring cavity and a second semicircular cavity which are arranged in sequence and are adjacent to each other. The sealing ring cavity is of a variable-diameter structure.

Description

Technical Field

[0001] This invention belongs to the field of steel wire pipe processing technology, specifically relating to a device and method for sealing the ends of steel wire pipes. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Steel wire mesh reinforced polyethylene composite pipe (hereinafter referred to as "steel wire pipe") is a composite pipe with polyethylene as the matrix and steel wire coated with adhesive resin continuously spirally wound into a mesh skeleton as the reinforcement. The reinforcement and matrix are melt-bonded with adhesive resin.

[0004] Due to the special composite structure of steel wire pipe, the pipe ends need to be sealed during normal use.

[0005] Conventional pipe ends are butt-welded using a sealing ring to seal the steel wire layer and adhesive layer on the end face. However, since the sealing process is done manually, the sealing quality is greatly affected by human factors. Furthermore, the linear expansion coefficients of steel wire and polyethylene are different. The stress caused by temperature differences after pipe production and during operation can easily cause the steel wire to push open and damage the sealing ring, leading to seal failure. Water can then enter the steel wire layer and adhesive layer through the sealing ring, causing the pipe to be "water-penetrated" and damaged. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a device and method for sealing the end of a steel wire pipe. This device can form a sealing joint that is integral with the steel wire pipe at the end, thereby solving the problem of sealing failure at the end of the steel wire pipe.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] In a first aspect, the present invention provides a device for sealing the end of a steel wire pipe, comprising an injection molding mold and a heating mold arranged coaxially, wherein the heating mold is reciprocating along the axial direction of the injection molding mold; the injection molding mold comprises a first mold body and a second mold body arranged opposite to each other, both the first mold body and the second mold body having cavities, and the cavities of the first mold body and the second mold body each comprising, in the axial direction, a first semicircular cavity, a sealing ring cavity and a second semicircular cavity arranged sequentially adjacent to each other, wherein the sealing ring cavity has a variable diameter structure.

[0009] As a further technical solution, the first mold body is fixedly installed, and the second mold body can reciprocate to move closer to or further away from the first mold body; the first mold body is fixedly connected to the fixed plate through a fixed connecting plate, and connecting rods are also fixedly installed at both ends of the fixed plate. The connecting rods are arranged radially along the first mold body, and the other end of the connecting rods is slidably connected to the sliding plate. The sliding plate is fixedly connected to the second mold body through the sliding connecting plate.

[0010] As a further technical solution, guide positioning rods are fixedly provided at both ends of the fixed connecting plate, and through holes are opened at both ends of the sliding connecting plate at positions corresponding to the guide positioning rods. The ends of the guide positioning rods can be inserted into the through holes of the sliding connecting plate for positioning and guidance.

[0011] As a further technical solution, the radial dimensions of the first semicircular cavity and the second semicircular cavity are both smaller than the radial dimension of the sealing ring cavity; when the wire tube is inserted into the injection molding mold and clamped, the first semicircular cavity is in contact with the outside of the wire tube, and the second semicircular cavity is in contact with the outside of the heating mold.

[0012] As a further technical solution, the sealing ring cavity includes a conical variable diameter cavity and a third semicircular cavity connected as one piece. The conical variable diameter cavity is connected to the first semicircular cavity, and the third semicircular cavity is connected to the second semicircular cavity. The radial dimension of the conical variable diameter cavity gradually increases from the end connected to the first semicircular cavity to the end connected to the third semicircular cavity.

[0013] As a further technical solution, an injection hole is provided on the side of the first mold body, and the injection hole is located in the middle of the cavity of the first mold body.

[0014] As a further technical solution, the heating mold includes a first heating plate and a second heating plate connected as one piece. The radial dimension of the first heating plate is smaller than that of the second heating plate. Resistance wires are provided on the side of the first heating plate and the end face of the second heating plate. The resistance wires are arranged in a ring on both the first heating plate and the second heating plate.

[0015] As a further technical solution, the radial dimension of the first heating plate is smaller than the inner diameter of the wire tube, and the radial dimension of the second heating plate is larger than the outer diameter of the wire tube. When the heating mold and the wire tube are engaged, the first heating plate is placed inside the wire tube and fits against the inner wall of the wire tube, and the second heating plate is placed at the end of the wire tube and fits against the end of the wire tube, so that both the inner wall and the end of the wire tube are heated; the end of the first heating plate is set with a conical structure.

[0016] As a further technical solution, the heating mold is connected to the hydraulic cylinder, and the hydraulic cylinder drives the heating mold to move back and forth; the specific moving direction of the second mold is perpendicular to the moving direction of the heating mold.

[0017] Secondly, the present invention also provides a method for sealing the end of a steel wire pipe, employing the apparatus described above, comprising the following steps:

[0018] The steel wire tube to be processed is placed between the first mold body and the second mold body, and the distance between the end of the steel wire tube and the end face of the injection molding mold is controlled. The steel wire tube enters from the side of the first semi-circular cavity.

[0019] The second mold body moves and clamps the wire tube with the first mold body;

[0020] The heating mold moves and enters the injection molding mold from the side of the second semi-circular cavity. The heating mold contacts the inner wall and end face of the steel wire tube, heating the inner wall and end face of the steel wire tube to a molten state.

[0021] The heating mold moves a set distance away from the injection molding mold, forming a closed cavity between the sealing ring cavity, the heating mold, and the wire tube, into which PE material is injected.

[0022] After the pressure holding time is set, the heating mold moves away from the injection molding mold, the second mold body moves away from the first mold body, the end sealing of the wire tube is completed, and the wire tube is removed.

[0023] A plastic injection sealing ring is formed at the end of the steel wire tube. The plastic injection sealing ring forms an integral structure with the outer layer and inner layer of the steel wire tube. The plastic injection sealing ring covers the end of the steel wire tube and the outer wall.

[0024] The beneficial effects of the present invention are as follows:

[0025] The device of the present invention has a sealing ring cavity in the injection molding mold. After the steel wire tube is inserted, the heating mold heats and melts the end and inner wall of the steel wire tube. Then, the sealing ring is formed by injection molding in the injection molding mold. The sealing ring and the steel wire tube are integrated, so there will be no problem of sealing failure. Moreover, the entire device is hydraulically driven to realize a series of actions, which is simple and easy to operate.

[0026] The method of this invention changes the traditional pipe end sealing method. It adopts an electrofusion + secondary molding injection process. Because the inner wall of the steel wire tube is relatively thick, the polyethylene material in this part is molten by electrofusion heating of the inner wall and end face. Then, a sealing ring is formed by secondary molding injection. The sealing ring is integrally injection molded with the inner and outer layers of the steel wire tube, which ensures that the pipe end of the steel wire tube is completely isolated from water and will not have the problem of "water penetration". This solves the sealing failure problem of the steel wire tube end and ensures product stability. At the same time, the improved sealing method increases the width of the pipe end sealing surface, which can realize the direct butt welding connection of the pipe, solving the industry problem that steel wire tubes cannot be directly butt welded. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 This is a side view of the injection molding die of the present invention;

[0029] Figure 2 This is a front view structural diagram of the device for sealing the ends of steel wire pipes according to the present invention;

[0030] Figure 3 This is an enlarged view of the heating mold of the present invention;

[0031] Figure 4 This is a schematic diagram of the clamping state of the injection molding mold of the present invention;

[0032] Figure 5 This is a schematic diagram of the device for sealing the end of a steel wire tube according to the present invention being inserted into the steel wire tube;

[0033] Figure 6 This is a schematic diagram of the heating mold and the steel wire pipe used in the device for sealing the end of the steel wire pipe according to the present invention.

[0034] Figure 7 This is a schematic diagram of the device for sealing the end of a steel wire pipe according to the present invention, in which the heated mold retracts to be flush with the sealing ring cavity of the mold.

[0035] Figure 8 This is a schematic diagram of the device for sealing the ends of steel wire pipes according to the present invention injecting PE material into an injection molding die;

[0036] Figure 9 This is a schematic diagram of the device for sealing the end of a steel wire pipe according to the present invention, showing the heating mold exiting the injection molding mold;

[0037] Figure 10 This invention provides a steel wire tube sealing structure.

[0038] In the diagram: the spacing or dimensions between parts have been exaggerated to show their positions; the diagram is for illustrative purposes only.

[0039] The components are as follows: 1. Outer layer of steel wire tube; 2. Steel wire layer; 3. Inner layer of steel wire tube; 4. Steel wire tube; 5. Injection sealing ring; 6. Fixing plate; 7. Sliding plate; 8. Connecting rod; 9. Fixed connecting plate; 10. First mold body; 11. Guide positioning rod; 12. Sliding connecting plate; 13. Second mold body; 14. Hydraulic cylinder; 15. Heating mold; 16. Injection hole; 17. Resistance wire; 18. First semi-circular cavity; 19. Sealing ring cavity; 20. Second semi-circular cavity; 21. First heating plate; 22. Second heating plate. Detailed Implementation

[0040] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0041] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Terminology Explanation: The terms "installation," "connection," "linking," and "fixing" appearing in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction relationship between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] In a typical embodiment of the present invention, such as Figures 1-2 As shown, a device for sealing the end of a steel wire tube is proposed, which includes a heating mold 15, a hydraulic cylinder 14 and an injection molding mold. The heating mold 15 and the hydraulic cylinder 14 are connected. The hydraulic cylinder 14 drives the heating mold 15 to move back and forth, heating the end of the steel wire tube in the injection molding mold, and then injecting and sealing the end of the steel wire tube.

[0045] The injection molding mold and the heating mold 15 are arranged opposite to each other. The heating mold 15 can be moved into the injection molding mold during heating or removed from the injection molding mold after heating.

[0046] The injection molding mold is a split type, which includes a first mold body 10 and a second mold body 13 arranged opposite to each other. The first mold body 10 is fixedly arranged, and the second mold body 13 can reciprocate to move closer to the first mold body 10 to clamp the steel wire tube, or move away from the first mold body 10 to release the steel wire tube.

[0047] It should be noted that the moving direction of the second mold body 13 is perpendicular to the moving direction of the heating mold 15. The heating mold 15 moves axially along the injection molding mold, while the second mold body 13 moves radially along the injection molding mold.

[0048] Specifically, the first mold body 10 is fixedly connected to the fixed connecting plate 9, the fixed connecting plate 9 is fixedly connected to the fixed plate 6, and the fixed plate 6 is also fixedly provided with connecting rods 8 at both ends. The connecting rods 8 are arranged radially along the first mold body 10 (that is, the moving direction of the second mold body). The other end of the connecting rod 8 is slidably connected to the sliding plate 7. The sliding plate 7 is fixedly connected to the sliding connecting plate 12, and the sliding connecting plate 12 is fixedly connected to the second mold body 13. The sliding plate 7 is hydraulically driven, that is, the sliding plate 7 can be connected to a hydraulic component to make the sliding plate 7 reciprocate on the connecting rod 8, thereby driving the clamping and opening of the second mold body 13 and the first mold body 10.

[0049] In this embodiment, the first mold body 10, the fixed connecting plate 9, and the fixed plate 6 are fixed by threaded connection, and the fixed plate 6 and the connecting rod 8 can also be fixed by threaded connection; the second mold body 13, the sliding connecting plate 12, and the sliding plate 7 are fixed by threaded connection, and a through hole is opened at the connection between the sliding plate 7 and the connecting rod 8 for the connecting rod 8 to pass through.

[0050] Guide positioning rods 11 are fixedly installed at both ends of the fixed connecting plate 9. Guide positioning blocks are installed at the ends of the guide positioning rods 11. Through holes are opened at both ends of the sliding connecting plate 12 at positions corresponding to the guide positioning blocks. The guide positioning blocks at the ends of the guide positioning rods 11 can be inserted into the through holes of the sliding connecting plate 12. During the clamping and opening process of the injection molding mold, the guide positioning rods 11 play a positioning and guiding role for the sliding connecting plate 12.

[0051] Both the first mold body 10 and the second mold body 13 have cavities. The cavities are semi-circular groove structures when viewed from the axial direction. After the first mold body 10 and the second mold body 13 are connected, their cavities fit together to form a complete cavity. The steel wire tube is inserted into the cavity and clamped.

[0052] The cavities of the first mold body 10 and the second mold body 13 include, in the axial direction, a first semi-circular cavity 18, a sealing ring cavity 19, and a second semi-circular cavity 20 arranged sequentially adjacent to each other. The radial dimensions of the first semi-circular cavity 18 and the second semi-circular cavity 20 are both smaller than the radial dimension of the sealing ring cavity 19. When the wire tube is inserted into the injection molding mold and clamped, the first semi-circular cavity 18 is in contact with the outside of the wire tube, and the second semi-circular cavity 20 is in contact with the outside of the heating mold 15.

[0053] The sealing ring cavity 19 is a variable diameter structure, comprising a conical variable diameter cavity and a third semicircular cavity connected as one piece. The conical variable diameter cavity is connected to the first semicircular cavity 18, and the third semicircular cavity is connected to the second semicircular cavity 20. The radial dimension of the conical variable diameter cavity gradually increases from the end connected to the first semicircular cavity 18 to the end connected to the third semicircular cavity. The minimum radial dimension of the conical variable diameter cavity is greater than the radial dimensions of the first semicircular cavity 18 and the second semicircular cavity 20, and the maximum radial dimension of the conical variable diameter cavity is the same as the radial dimension of the third semicircular cavity. After the steel wire tube is placed into the injection molding mold, a pipe end sealing structure is injection molded at the sealing ring cavity 19.

[0054] The first mold body 10 is provided with an injection hole 16 on its side. The injection hole 16 is located in the middle of the cavity of the first mold body 10 to inject material into the injection molding mold.

[0055] The heating mold 15 is arranged along the axial direction of the injection molding mold, and the heating mold 15 and the injection molding mold are coaxially arranged. The heating mold 15 is an integral structure. The heating mold 15 is located on the side of the second semi-circular cavity 20 of the injection molding mold.

[0056] The hydraulic cylinder 14 is the driving device for the heating mold 15, which can ensure that the heating mold 15 moves back and forth along the axial direction of the injection molding mold.

[0057] The heating mold 15 has a stepped disc structure, which includes a first heating plate 21 and a second heating plate 22 connected as one piece. The radial dimension of the first heating plate 21 is smaller than that of the second heating plate 22. The first heating plate 21 and the second heating plate 22 form a stepped structure. Resistance wires 17 are provided on the side of the first heating plate 21 and the end face of the second heating plate 22. The resistance wires are arranged in a ring on both the first heating plate and the second heating plate. The resistance wires on the end face of the second heating plate are provided on the radial end face that extends beyond the first heating plate 21. Thus, resistance wires 17 are provided on both vertical surfaces of the stepped structure of the heating mold 15 for heating the inner wall and end of the steel wire tube.

[0058] The radial dimension of the first heating plate 21 is smaller than the inner diameter of the wire tube 4, and the radial dimension of the second heating plate 22 is larger than the outer diameter of the wire tube 4. When the heating mold 15 is fitted with the wire tube 4, the first heating plate 21 is placed inside the wire tube and fits against the inner wall of the wire tube, and the second heating plate 22 is placed at the end of the wire tube and fits against the end of the wire tube, so that both the inner wall and the end of the wire tube are heated.

[0059] To facilitate the entry of the heating mold 15 into the wire tube, the end of the first heating plate 21 is designed with a tapered structure, which makes it easier to enter the wire tube and will not damage the end of the wire tube.

[0060] In another typical embodiment of the present invention, a method for sealing the ends of a steel wire tube is proposed, which employs the device described above, such as... Figures 5-9 As shown, it includes the following steps:

[0061] The steel wire tube 4 to be processed is placed between the first mold body 10 and the second mold body 13, and the distance between the end of the steel wire tube and the end face of the mold is controlled. The steel wire tube 4 enters from the side of the first semi-circular cavity 18 of the injection molding mold.

[0062] The hydraulic station is started, which drives the sliding plate 7 to move radially along the injection molding mold. The second mold body 13 approaches the first mold body 10, and the first mold body 10 and the second mold body 13 clamp the steel wire tube.

[0063] The hydraulic cylinder 14 is activated to drive the heating mold 15 to move axially along the injection molding mold. The heating mold 15 moves closer to the injection molding mold and is partially placed inside the wire tube. The heating mold 15 enters from the side of the second semi-circular cavity 20 of the injection molding mold. The heating mold 15 contacts the inner wall and end face of the wire tube: the first heating plate contacts the inner wall of the wire tube, and the second heating plate contacts the end face of the wire tube.

[0064] Turn on the power supply of the heating mold 15 to make the resistance wire 17 work and heat the inner wall and end face of the steel wire tube to a molten state;

[0065] The hydraulic cylinder 14 is activated to drive the heating mold 15 to move along the axial direction of the injection molding mold. The heating mold 15 moves away from the injection molding mold, ensuring that the vertical surface of the heating mold 15 is flush with the inner wall of the injection molding mold. That is, the ends of the second heating plate 22 and the sealing ring cavity 19 are flush, and a closed cavity is formed between the sealing ring cavity 19, the heating mold 15, and the wire tube 4.

[0066] Start the injection molding machine and inject PE material into the closed cavity through injection hole 16;

[0067] After holding the pressure for a certain period of time, the hydraulic cylinder 14 is activated to drive the heating mold 15 to move axially along the injection molding mold. The heating mold 15 moves away from the injection molding mold. The hydraulic station is activated to drive the sliding plate 7 to move radially along the injection molding mold. The second mold body 13 moves away from the first mold body 10, and the pipe end sealing process is completed (e.g. Figure 9 (As shown in the finished product), remove the steel wire tube.

[0068] After the steel wire tube end is sealed by the above-mentioned device and method, the structure of the steel wire tube 4 includes an outer layer 1 and an inner layer 3. A steel wire layer 2 is provided between the outer layer 1 and the inner layer 3. The entire steel wire tube 4 end is provided with an injection-molded sealing ring 5. The injection-molded sealing ring 5 forms an integral structure with the outer layer 1 and the inner layer 3 of the steel wire tube. The injection-molded sealing ring 5 covers the end of the steel wire tube and the outer wall.

[0069] Compared with the existing technology of setting PE sealing rings at the ends of steel wire pipes, the ends of steel wire pipes sealed by this invention are completely isolated from water, and there will be no "water penetration" problem.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for sealing the ends of a steel wire hose, characterized in that, The system includes an injection molding mold and a heating mold arranged coaxially. The heating mold can reciprocate along the axial direction of the injection molding mold. The injection molding mold includes a first mold body and a second mold body arranged opposite to each other. Both the first mold body and the second mold body have cavities. The cavities of the first mold body and the second mold body each include a first semi-circular cavity, a sealing ring cavity, and a second semi-circular cavity arranged sequentially adjacent to each other in the axial direction. The sealing ring cavity has a variable diameter structure. The heating mold includes a first heating plate and a second heating plate connected as one piece. The radial dimension of the first heating plate is smaller than that of the second heating plate. Resistance wires are provided on the side of the first heating plate and the end face of the second heating plate. The resistance wires are arranged in a ring on both the first heating plate and the second heating plate. The radial dimension of the first heating plate is smaller than the inner diameter of the wire tube, and the radial dimension of the second heating plate is larger than the outer diameter of the wire tube. When the heating mold is fitted with the wire tube, the first heating plate is placed inside the wire tube and fits against the inner wall of the wire tube, and the second heating plate is placed at the end of the wire tube and fits against the end of the wire tube, so that both the inner wall and the end of the wire tube are heated. The end of the first heating plate is set with a tapered structure.

2. The apparatus as claimed in claim 1, characterized in that, The first mold body is fixedly installed, and the second mold body can reciprocate to move closer to or further away from the first mold body; the first mold body is fixedly connected to a fixed plate through a fixed connecting plate, and connecting rods are also fixedly installed at both ends of the fixed plate. The connecting rods are arranged radially along the first mold body, and the other end of the connecting rods is slidably connected to a sliding plate. The sliding plate is fixedly connected to the second mold body through a sliding connecting plate.

3. The apparatus as described in claim 2, characterized in that, Guide positioning rods are fixedly installed at both ends of the fixed connecting plate, and through holes are opened at both ends of the sliding connecting plate at positions corresponding to the guide positioning rods. The ends of the guide positioning rods can be inserted into the through holes of the sliding connecting plate for positioning and guidance.

4. The apparatus as claimed in claim 1, characterized in that, The radial dimensions of the first and second semicircular cavities are both smaller than the radial dimension of the sealing ring cavity; when the wire tube is inserted into the injection molding mold and clamped, the first semicircular cavity is in contact with the outside of the wire tube, and the second semicircular cavity is in contact with the outside of the heating mold.

5. The apparatus as claimed in claim 1, characterized in that, The sealing ring cavity includes a tapered variable diameter cavity and a third semicircular cavity connected as one piece. The tapered variable diameter cavity is connected to the first semicircular cavity, and the third semicircular cavity is connected to the second semicircular cavity. The radial dimension of the tapered variable diameter cavity gradually increases from the end connected to the first semicircular cavity to the end connected to the third semicircular cavity.

6. The apparatus as claimed in claim 1, characterized in that, The first mold body has an injection hole on its side, which is located in the middle of the cavity of the first mold body.

7. The apparatus as claimed in claim 1, characterized in that, The heating mold is connected to the hydraulic cylinder, and the hydraulic cylinder drives the heating mold to move back and forth; the specific moving direction of the second mold is perpendicular to the moving direction of the heating mold.

8. A method for sealing the ends of a steel wire hose, characterized in that, Using the apparatus as described in any one of claims 1-7, the method includes the following steps: The steel wire tube to be processed is placed between the first mold body and the second mold body, and the distance between the end of the steel wire tube and the end face of the injection molding mold is controlled. The steel wire tube enters from the side of the first semi-circular cavity. The second mold body moves and clamps the wire tube with the first mold body; The heating mold moves and enters the injection molding mold from the side of the second semi-circular cavity. The heating mold contacts the inner wall and end face of the steel wire tube, heating the inner wall and end face of the steel wire tube to a molten state. The heating mold moves a set distance away from the injection molding mold, forming a closed cavity between the sealing ring cavity, the heating mold, and the wire tube, into which PE material is injected. After the pressure holding time is set, the heating mold moves away from the injection molding mold, the second mold body moves away from the first mold body, the end sealing of the wire tube is completed, and the wire tube is removed. A plastic injection sealing ring is formed at the end of the steel wire tube. The plastic injection sealing ring forms an integral structure with the outer layer and inner layer of the steel wire tube. The plastic injection sealing ring covers the end of the steel wire tube and the outer wall.

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