Pipe joint and injection molding system thereof

Abstract

The utility model relates to the technical field of pipeline connection more particularly, relate to a kind of pipeline joint and its injection molding system, pipeline joint includes inner pipe head, outer pipe head, butt joint part and be used for with the steel sleeve of pipeline inner wall conforming, inner pipe head, outer pipe head, butt joint part and steel sleeve are all annular structure, inner pipe head and outer pipe head are connected with butt joint part, the outer wall of inner pipe head, the inner wall of outer pipe head and the end surface of butt joint part form annular slot for installing pipeline, steel sleeve is towards butt joint part and is butt-jointed, steel sleeve can resist the pressure that pipeline is subjected to due to geological change, conveying medium impact and other reasons in use process, improve the pressure-bearing capacity of pipeline, prevent pipeline damage;Pipeline joint injection molding system includes injection mold, pipeline and the pipeline joint as described before, the outer wall of steel sleeve and the inner wall of pipeline butt-jointed, the inner wall of steel sleeve and the inner wall of cavity butt-jointed, steel sleeve can resist the pressure that pipeline is subjected to when injection mold is closed, prevent pipeline from breaking.

Description

Technical Field

[0001] This utility model relates to the technical field of pipe connection, and more specifically, to a pipe joint and its injection molding system. Background Technology

[0002] Trenchless pipeline construction is widely used in the construction of new pipelines for water supply, drainage, electricity, communications, and gas. Pipe joints are required to connect the pipes. In existing pipeline connection technologies, the outer surface of the pipe and the inner surface of the joint are often connected by heat fusion. However, the pressure-bearing capacity of the pipe at the joint is relatively low, and cracks are prone to occur due to geological changes and other reasons. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies in terms of the weak pressure-bearing capacity of pipes at joints, and to provide a pipe joint and its injection molding system that can improve the pressure-bearing capacity of pipes at joints.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: A pipe fitting is provided, comprising an inner pipe head, an outer pipe head, a mating portion, and a steel sleeve for fitting against the inner wall of a pipe. The inner pipe head, the outer pipe head, the mating portion, and the steel sleeve are all annular structures. The inner pipe head and the outer pipe head are both connected to the mating portion. The outer wall of the inner pipe head, the inner wall of the outer pipe head, and the end face of the mating portion form an annular slot for installing a pipe. The end face of the steel sleeve facing the mating portion abuts against the end of the inner pipe head away from the mating portion.

[0005] In the production of this utility model of pipe joint, a steel sleeve is inserted into the pipe, with the outer wall of the steel sleeve abutting against the inner wall of the pipe. The combined structure of the pipe and the steel sleeve is then inserted into the cavity of an injection mold, molten material is injected, and the joint is formed upon cooling. At this point, the pipe is inserted into the slot, and the steel sleeve abuts against the inner pipe head. When connecting two pipe sections, the end faces of the two pipe joints connected to the two pipe sections, away from the outer and inner pipe heads, are heat-fused together, thereby connecting the two pipe sections together. The steel sleeve can resist the pressure on the pipe during use due to geological changes, impacts from the transported medium, etc., improving the pipe's pressure-bearing capacity and preventing pipe damage.

[0006] Furthermore, the inner wall of the steel sleeve is flush with the inner wall of the inner tube head. This flush alignment prevents the liquid from experiencing increased resistance due to the abrupt change in inner diameter at the junction of the steel sleeve and the inner tube head, thus reducing the flow velocity. Simultaneously, it prevents sediment and other deposits in the liquid from accumulating at the junction, thus avoiding blockage of the joint.

[0007] Furthermore, the end face of the inner tube head that abuts against the steel sleeve is inclined inward. Let the direction towards the axis of the inner tube head be defined as "inward"; the inclined abutment surface of the inner tube head and the steel sleeve increases the contact area compared to a flat abutment, making the connection between the inner tube head and the steel sleeve more secure after injection molding; at the same time, at the junction of the inner tube head and the steel sleeve, the inner tube head and the steel sleeve can jointly resist the external pressure of the pipeline and the liquid pressure, enhancing the pressure-bearing capacity of the joint.

[0008] Furthermore, the outer pipe head includes a thick pipe section, which is connected to the mating part. The thickness of the thick pipe section is greater than the thickness of the inner pipe head. The thick pipe section enhances the pressure-bearing capacity and structural strength of the joint, further improving the pressure-bearing capacity of the pipeline; at the same time, it can increase the contact area when the two mating parts are joined, making the connection between the mating parts more stable.

[0009] Furthermore, the outer pipe joint also includes a thin pipe section and a flared section. The thickness of the thin pipe section is less than the thickness of the thick pipe section. The flared section connects the thin pipe section and the thick pipe section, and the thickness of the flared section gradually increases in the direction away from the thin pipe section. The gradually changing thickness of the flared section effectively disperses the stress on the outer pipe joint, prevents stress concentration, and extends the service life of the joint.

[0010] A pipe fitting injection molding system is provided, including an injection mold, a pipe, and a pipe fitting as described above. The injection mold has a cavity, and the top of the injection mold has an opening communicating with the cavity. The injection mold also has a flow channel communicating with the cavity. The pipe and the steel sleeve are inserted into the cavity through the opening. The outer wall of the steel sleeve abuts against the inner wall of the pipe, and the inner wall of the steel sleeve abuts against the inner wall of the cavity. The shapes of the inner pipe head, the outer pipe head, and the mating portion are adapted to the shape of the cavity.

[0011] This utility model discloses a pipe joint injection molding system in which the pipe is inserted into the mold cavity vertically downwards. In use, the pipe and steel sleeve are inserted into the mold cavity through the opening at the top of the mold. The mold is then closed, and molten material is injected into the cavity through the runner. The steel sleeve resists the pressure on the pipe during mold closure and blocks the molten material, preventing it from flowing away from the mold. After the molten material fills the cavity, it cools and solidifies, is demolded, and the pipe and injection joint are removed, completing the production of the pipe joint. Injection molding integrates the pipe and pipe joint, providing a stable connection without requiring additional assembly steps, thus simplifying the production process.

[0012] Furthermore, the injection mold includes an outer mold, a core, and a positioning block. The outer mold is fitted onto the core, and the positioning block is detachably mounted on the top of the outer mold. The cavity is located between the inner wall of the outer mold, the core, and the bottom surface of the positioning block. The flow channel is located between the inner wall of the outer mold and the core. The top of the outer mold has an opening communicating with the cavity. The positioning block has a positioning hole that communicates with the cavity through the opening on the top of the outer mold. The positioning hole is coaxial with the core. The pipe is inserted into the positioning hole, with the outer wall of the pipe abutting against the inner wall of the positioning hole. The inner wall of the steel sleeve abuts against the core. The positioning hole of the positioning block positions the outer wall of the pipe, and the steel sleeve fitted onto the core positions the inner wall of the pipe. The positioning hole and the steel sleeve cooperate to achieve precise positioning and fixation of the horizontal position of the pipe. The friction between the positioning ring, the steel sleeve, and the pipe together achieves fixation of the vertical position of the pipe.

[0013] Furthermore, the positioning block includes two sets of clamping blocks for clamping the pipe. The clamping blocks are detachably installed on the top of the outer mold. Each clamping block has a positioning groove for splicing into a complete positioning hole. The outer wall of the pipe abuts against the inner walls of the two sets of positioning grooves. When installing the pipe, the two sets of clamping blocks are first separated, the pipe is placed between the positioning grooves, and then the two sets of clamping blocks are closed so that the outer wall of the pipe abuts tightly against the inner wall of the positioning groove. After injection molding, the two sets of clamping blocks are separated, and the mold core is separated from the outer mold, so the molded pipe joint can be easily removed. The operation is convenient. The splicing design of the two sets of clamping blocks solves the problem of difficult pipe installation and removal. There is no need to forcibly insert or remove the pipe, avoiding damage to the outer wall of the pipe or the joint components during installation and removal, and improving the product qualification rate.

[0014] Furthermore, the mold core includes a mold core body and a sleeve, the sleeve being detachably fitted onto the mold core body, and the inner wall of the inner tube head and the inner wall of the steel sleeve abutting against the outer wall of the sleeve. The outer wall of the sleeve, as part of the cavity, serves to shape the pipe joint. The shape of the pipe joint can be changed by replacing sleeves of different shapes without replacing the entire mold core, thus enhancing the flexibility of the injection molding system.

[0015] Furthermore, the pipe is a composite pipe, comprising an outer layer, a reinforcing layer, and an inner layer connected sequentially from the outside to the inside. The end of the inner layer extends outward to form a seal covering the end face of the reinforcing layer. The seal separates the reinforcing layer from the cavity and fits into the mating portion. When sealing the pipe, a portion of the outer layer and reinforcing layer at the pipe end is cut away, allowing the inner layer at the pipe end to melt, press, and cool to form a seal. Compared to welding a sealing ring to the pipe end, the seal formed by melting and cooling the inner layer is less likely to detach from the pipe end and reduces costs. The seal prevents direct contact between the reinforcing layer and the molten material in the cavity, preventing molten material from entering between the outer and inner layers, causing corrosion or damage to the reinforcing layer, and affecting the pipe's strength.

[0016] Compared with the prior art, the beneficial effects of this utility model are: The pipe joint of this utility model: 1. Utilizes a steel sleeve to resist the pressure on the pipeline during use due to geological changes, impacts from the transported medium, etc., thereby improving the pipeline's pressure-bearing capacity and preventing pipeline damage; 2. The contact surface between the inner pipe head and the steel sleeve is inclined, which increases the contact area compared to a flat contact, making the connection between the inner pipe head and the steel sleeve more secure after injection molding and enhancing the pressure-bearing capacity; 3. The thick pipe section increases the contact area when the two joints are joined, making the weld between the joints more stable. The pipe joint injection molding system of this utility model has the following advantages: 1. The steel sleeve can resist the pressure on the pipe when the injection mold is closed, preventing the pipe from breaking; 2. The steel sleeve blocks the molten material, preventing the molten material from flowing to the end of the pipe away from the mold; 3. The shape of the pipe joint can be changed by changing the sleeve of different shapes without replacing the entire mold core, enhancing the flexibility of the injection molding system; 4. The inner layer of the pipe and the seal are integrally molded, making the seal less likely to fall off from the end of the pipe. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the pipe joint of this utility model; Figure 2 This is a schematic diagram of the assembly of the pipe joint and the pipe of this utility model; Figure 3 This is a schematic diagram of the pipe joint injection molding system of this utility model.

[0018] In the attached diagram: 1. Outer pipe head; 11. Thick pipe section; 12. Thin pipe section; 13. Flared section; 2. Inner pipe head; 3. Joint; 4. Steel sleeve; 5. Outer mold; 6. Mold core; 61. Mold core body; 62. Sleeve; 7. Positioning block; 71. Clamping block; 72. Protrusion; 73. Positioning hole; 8. Pipe. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0020] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0021] Example 1 like Figure 1 and Figure 2 The first embodiment of the pipe joint of this utility model is shown, including an inner pipe head 2, an outer pipe head 1, a connecting part 3, and a steel sleeve 4 for fitting against the inner wall of the pipe 8. The inner pipe head 2, the outer pipe head 1, the connecting part 3, and the steel sleeve 4 are all annular structures. The inner pipe head 2 and the outer pipe head 1 are both connected to the connecting part 3. The outer wall of the inner pipe head 2, the inner wall of the outer pipe head 1, and the end face of the connecting part 3 form an annular slot for installing the pipe 8. The end face of the steel sleeve 4 facing the connecting part 3 abuts against the end of the inner pipe head 2 away from the connecting part 3.

[0022] In the production of this utility model pipe joint, the steel sleeve 4 is inserted into the pipe 8, so that the outer wall of the steel sleeve 4 abuts against the inner wall of the pipe 8. Figure 2 As shown; the combined structure of pipe 8 and steel sleeve 4 is inserted into the cavity of the injection mold, molten material is injected, and after cooling, a pipe joint is formed. At this time, pipe 8 is inserted into the slot, and steel sleeve 4 abuts against inner pipe head 2, as shown. Figure 2 As shown; when connecting two pipe sections 8, the end faces of the two pipe joints 3 that are connected to the two pipe sections 8 respectively are heat-fused and welded together, thereby connecting the two pipe sections 8 together; the steel sleeve 4 can resist the pressure on the pipe 8 during the mold closing process and during use, improve the pressure bearing capacity of the pipe 8, and prevent the pipe 8 from being damaged.

[0023] like Figure 1As shown, the inner wall of the steel sleeve 4 is flush with the inner wall of the inner tube head 2. This flush alignment prevents the flow velocity from decreasing due to increased resistance caused by a sudden change in inner diameter at the junction of the steel sleeve 4 and the inner tube head 2. It also prevents sediment and other deposits in the medium from accumulating at the junction, thus avoiding blockage of the joint.

[0024] The end face of the inner tube head 2 that abuts against the steel sleeve 4 is inclined inward. Let the direction towards the axis of the inner tube head 2 be defined as "inward"; the inclined abutment surface of the inner tube head 2 and the steel sleeve 4 increases the contact area compared to a flat abutment, making the connection between the inner tube head 2 and the steel sleeve 4 more secure after injection molding; at the same time, at the junction of the inner tube head 2 and the steel sleeve 4, the inner tube head 2 and the steel sleeve 4 can jointly resist the external pressure and medium pressure of the pipeline 8, enhancing the pressure-bearing capacity of the joint.

[0025] like Figure 1 As shown, the outer pipe head 1 includes a thick pipe section 11, which is connected to the connecting part 3. The thickness of the thick pipe section 11 is greater than the thickness of the inner pipe head 2. The thick pipe section 11 enhances the pressure-bearing capacity and structural strength of the joint, further improving the pressure-bearing capacity of the pipeline 8; at the same time, it can increase the contact area when the two connecting parts 3 are connected, making the fusion between the connecting parts 3 more stable.

[0026] The outer pipe joint 1 also includes a thin pipe section 12 and a flared section 13. The thickness of the thin pipe section 12 is less than the thickness of the thick pipe section 11. The flared section 13 connects the thin pipe section 12 and the thick pipe section 11, and the thickness of the flared section 13 gradually increases in the direction away from the thin pipe section 12. The gradually changing thickness of the flared section 13 effectively disperses the stress of the outer pipe joint 1, prevents stress concentration in the outer pipe joint 1, and extends the service life of the joint.

[0027] Example 2 This embodiment is the first embodiment of the pipe joint injection molding system of this utility model, such as... Figure 3 As shown, the device includes an injection mold, a pipe 8, and a pipe connector as described in Embodiment 1. The injection mold has a cavity, and the top of the injection mold has an opening that communicates with the cavity. The injection mold also has a flow channel that communicates with the cavity. The pipe 8 and the steel sleeve 4 are inserted into the cavity through the opening. The outer wall of the steel sleeve 4 abuts against the inner wall of the pipe 8, and the inner wall of the steel sleeve 4 abuts against the inner wall of the cavity. The shapes of the inner pipe head 2, the outer pipe head 1, and the connecting part 3 are adapted to the shape of the cavity.

[0028] This utility model discloses a pipe joint injection molding system. The mold core 6 is inserted vertically upwards into the pipe 8. In use, the pipe 8 and steel sleeve 4 are inserted into the cavity of the injection mold through the opening at the top of the mold. The mold is closed, and molten material is injected into the cavity through the runner. The steel sleeve 4 resists the pressure on the pipe 8 when the mold is closed, preventing the pipe 8 from rupturing and blocking the molten material from flowing away from the mold. After the molten material fills the cavity, it cools and solidifies, is demolded, and the pipe 8 and injection joint are removed, completing the production of the pipe joint. Injection molding integrates the pipe 8 and the pipe joint, providing a stable connection without requiring additional assembly steps, thus simplifying the production process.

[0029] like Figure 3 As shown, the injection mold includes an outer mold 5, a mold core 6, and a positioning block 7. The outer mold 5 is fitted onto the mold core 6. The positioning block 7 is detachably installed on the top of the outer mold 5. The cavity is located between the inner wall of the outer mold 5, the bottom surface of the mold core 6, and the positioning block 7. The runner is located between the inner wall of the outer mold 5 and the mold core 6. The top of the outer mold 5 has an opening that communicates with the cavity. The positioning block 7 has a positioning hole 73. The positioning hole 73 communicates with the cavity through the opening on the top of the outer mold 5. The positioning hole 73 is coaxial with the mold core 6. The pipe 8 is inserted into the positioning hole 73. The outer wall of the pipe 8 abuts against the inner wall of the positioning hole 73. The inner wall of the steel sleeve 4 abuts against the mold core 6. The positioning hole 73 of the positioning block 7 positions the outer wall of the pipe 8, and the steel sleeve 4 fitted on the mold core 6 positions the inner wall of the pipe 8. The positioning hole 73 and the steel sleeve 4 cooperate to achieve precise positioning and fixation of the horizontal position of the pipe 8. The friction between the positioning ring and the steel sleeve 4 and the pipe 8 together achieves fixation of the vertical position of the pipe 8.

[0030] The positioning block 7 includes two sets of clamping blocks 71 for clamping the pipe 8. The clamping blocks 71 are detachably installed on the top of the outer mold 5. The clamping blocks 71 are provided with positioning grooves for splicing into a complete positioning hole 73. The outer wall of the pipe 8 abuts against the inner wall of the two sets of positioning grooves. When installing the pipe 8, first separate the two sets of clamping blocks 71, place the pipe 8 between the positioning grooves, and then close the two sets of clamping blocks 71 so that the outer wall of the pipe 8 abuts tightly against the inner wall of the positioning groove. After injection molding, separate the two sets of clamping blocks 71 and separate the mold core 6 from the outer mold 5. The molded pipe joint can then be easily removed, making the operation convenient. The splicing design of the two sets of clamping blocks 71 solves the problem of difficult installation and removal of the pipe 8. There is no need to forcibly insert or remove the pipe 8, avoiding damage to the outer wall of the pipe 8 or the joint components during installation and removal, and improving the product qualification rate.

[0031] In this embodiment, two clamping blocks 71 are provided, and both positioning grooves are semi-circular grooves. The bottom of each clamping block 71 is provided with a protrusion 72, which is a semi-circular ring structure. The inner diameter of the protrusion 72 is equal to the inner diameter of the positioning hole 73. The top of the outer mold 5 is provided with an installation groove, and the opening at the top of the outer mold 5 is located at the bottom of the installation groove. The outer walls of the two protrusions 72 abut against the side walls of the installation groove.

[0032] like Figure 3 As shown, the mold core 6 includes a mold core body 61 and a sleeve 62. The sleeve 62 is detachably fitted onto the mold core body 61, and the inner walls of the inner tube head 2 and the steel sleeve 4 abut against the outer wall of the sleeve 62. The outer wall of the sleeve 62, as part of the cavity, serves to shape the pipe joint. The shape of the pipe joint can be changed by replacing sleeves 62 of different shapes without replacing the entire mold core 6, thus enhancing the flexibility of the injection molding system. In this embodiment, the sleeve 62 is fixedly connected to the mold core body 61 by bolts.

[0033] The working principle of the pipe joint injection molding system in this embodiment is as follows: In use, the sleeve 62 is fitted onto the mold core body 61, the steel sleeve 4 is inserted into the pipe 8, so that the outer wall of the steel sleeve 4 abuts against the inner wall of the pipe 8, and the pipe 8 is clamped between the two positioning grooves by two clamping blocks 71. The pipe 8 and the steel sleeve 4 are inserted into the cavity through the opening at the top of the injection mold, and the protrusion 72 of the clamping block 71 is inserted into the mounting groove. The mold core 6 is inserted into the pipe 8 from bottom to top, so that the inner wall of the steel sleeve 4 abuts against the sleeve 62. The clamping block 71 and the mold core 6 together fix the position of the pipe 8. Molten material is injected into the cavity through the flow channel. The steel sleeve 4 can resist the pressure on the pipe 8 when the injection mold is closed and block the molten material to prevent the molten material from flowing to the end of the pipe 8 away from the mold. After the molten material fills the cavity, it cools and solidifies, demolds, and removes the pipe 8 and the injection joint to complete the production of the pipe joint.

[0034] Example 3 This embodiment is the second embodiment of the pipe joint injection molding system of this utility model. This embodiment is similar to Embodiment 2, except that the pipe 8 is a composite pipe, comprising an outer layer, a reinforcing layer, and an inner layer connected sequentially from the outside to the inside. The end of the inner layer extends outward to form a seal covering the end face of the reinforcing layer. The seal separates the reinforcing layer from the cavity and fits against the butt joint 3. When sealing the pipe 8, a portion of the outer layer and reinforcing layer at the end of the pipe 8 is cut off, allowing the inner layer at the end of the pipe 8 to melt, press, and cool to form a seal. Compared to welding a sealing ring to the end of the pipe 8, the seal formed by melting and cooling the inner layer is less likely to detach from the end of the pipe 8 and can reduce costs. The seal can prevent the reinforcing layer from directly contacting the molten material in the cavity, preventing the molten material from entering between the outer and inner layers, causing corrosion or damage to the reinforcing layer, and affecting the strength of the pipe 8. In this embodiment, the pipe 8 is a wire mesh pipe, the outer and inner layers are made of high-strength polyethylene material, and the reinforcing layer is a wire winding structure.

[0035] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0036] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A pipe fitting, characterized in that, It includes an inner pipe head (2), an outer pipe head (1), a connecting part (3), and a steel sleeve (4) for fitting against the inner wall of the pipe (8). The inner pipe head (2), the outer pipe head (1), the connecting part (3), and the steel sleeve (4) are all annular structures. The inner pipe head (2) and the outer pipe head (1) are both connected to the connecting part (3). The outer wall of the inner pipe head (2), the inner wall of the outer pipe head (1), and the end face of the connecting part (3) form an annular slot for installing the pipe (8). The end face of the steel sleeve (4) facing the connecting part (3) abuts against the end of the inner pipe head (2) away from the connecting part (3).

2. The pipe joint according to claim 1, characterized in that, The inner wall of the steel sleeve (4) is flush with the inner wall of the inner tube head (2).

3. The pipe joint according to claim 1, characterized in that, The end face of the inner tube head (2) that abuts against the steel sleeve (4) is inclined inward.

4. The pipe joint according to claim 1, characterized in that, The outer tube head (1) includes a thick tube section (11), which is connected to the docking part (3), and the thickness of the thick tube section (11) is greater than the thickness of the inner tube head (2).

5. The pipe joint according to claim 4, characterized in that, The outer tube head (1) also includes a thin tube section (12) and a flared section (13). The thickness of the thin tube section (12) is less than the thickness of the thick tube section (11). The flared section (13) is connected between the thin tube section (12) and the thick tube section (11). The thickness of the flared section (13) gradually increases in the direction away from the thin tube section (12).

6. A pipe fitting injection molding system, characterized in that, The device includes an injection mold, a pipe (8), and a pipe fitting as described in any one of claims 1 to 5. The injection mold has a cavity with an opening at the top. The injection mold also has a flow channel that communicates with the cavity. The pipe (8) and the steel sleeve (4) are inserted into the cavity through the opening. The outer wall of the steel sleeve (4) abuts against the inner wall of the pipe (8), and the inner wall of the steel sleeve (4) abuts against the inner wall of the cavity. The shapes of the inner pipe head (2), the outer pipe head (1), and the mating part (3) are adapted to the shape of the cavity.

7. The pipe joint injection molding system according to claim 6, characterized in that, The injection mold includes an outer mold (5), a mold core (6), and a positioning block (7). The outer mold (5) is fitted onto the mold core (6). The positioning block (7) is detachably installed on the top of the outer mold (5). The cavity is located between the inner wall of the outer mold (5), the bottom surface of the mold core (6), and the positioning block (7). The flow channel is located between the inner wall of the outer mold (5) and the mold core (6). The positioning block (7) has a positioning hole (73) that communicates with the cavity. The positioning hole (73) is coaxial with the mold core (6). The pipe (8) is inserted into the positioning hole (73). The outer wall of the pipe (8) abuts against the inner wall of the positioning hole (73). The inner wall of the steel sleeve (4) abuts against the mold core (6).

8. The pipe joint injection molding system according to claim 7, characterized in that, The positioning block (7) includes two sets of clamping blocks (71) for clamping the pipe (8). The clamping blocks (71) are detachably installed on the top of the outer mold (5). The clamping blocks (71) are provided with positioning grooves for splicing into the complete positioning hole (73). The outer wall of the pipe (8) abuts against the inner wall of the two sets of positioning grooves.

9. The pipe joint injection molding system according to claim 7, characterized in that, The mold core (6) includes a mold core body (61) and a sleeve (62). The sleeve (62) is detachably fitted onto the mold core body (61). The inner wall of the inner tube head (2) and the inner wall of the steel sleeve (4) abut against the outer wall of the sleeve (62).

10. The pipe joint injection molding system according to claim 6, characterized in that, The pipe (8) is a composite pipe, which includes an outer layer, a reinforcing layer and an inner layer connected sequentially from the outside to the inside. The end of the inner layer extends outward to form a seal covering the end face of the reinforcing layer. The seal separates the reinforcing layer from the cavity and fits the joint (3).

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