Petroleum pipeline nut and forming apparatus and method of manufacture

Abstract

The application discloses a petroleum pipeline nut and a forming device and a manufacturing method, relates to the field of nut manufacturing, and comprises a nut body, an inner threaded hole is formed in the nut body, and a groove is formed in the outer circumferential surface of the nut body; a supporting cylinder is connected with the nut body at the opening side of the supporting cylinder, the supporting cylinder is provided with an accommodating cavity, the accommodating cavity is communicated with the inner threaded hole, and the accommodating cavity is used for accommodating the protruding part of a bolt matched with the nut body; a plastic shell is wrapped on the outer wall of the supporting cylinder and the nut body, the inner threaded hole is exposed on the side of the supporting cylinder, and the plastic shell is provided with a protrusion matched with the groove, so that the plastic shell is fixedly connected with the nut body. Through the above technical scheme, the corrosion-resistant petroleum pipeline nut is provided.

Description

Technical Field

[0001] This application relates to the field of nut manufacturing, and in particular to an oil pipeline nut, a forming device, and a manufacturing method. Background Technology

[0002] Currently, with the increasing demand for oil resources, various oil transportation pipeline projects are becoming more and more common. Many oil pipelines are constructed underground, which greatly facilitates the transportation of oil resources. However, due to the often complex underground environment, corrosion is easily caused. Not only will the pipeline equipment corrode, but the connecting components will also be corroded. Corrosion seriously affects the safety of pipeline operation and must be given high priority.

[0003] During oil pipeline construction, technicians typically use plastic protective sleeves to protect nuts and bolts. These sleeves are generally corrosion-resistant and are placed on the nut after it has been fitted with the bolt. These sleeves are usually hexagonal at the bottom and semi-circular or semi-elliptical at the top to accommodate the bolt. However, in actual installation, these sleeves are prone to falling off. Furthermore, since each nut size requires a different protective sleeve, matching each sleeve to the nut individually during installation is time-consuming. Therefore, there is an urgent need to produce a corrosion-resistant nut for oil pipelines. Summary of the Invention

[0004] The purpose of this application is to provide an oil pipeline nut, a forming device, and a manufacturing method.

[0005] First aspect

[0006] This application provides an oil pipeline nut comprising:

[0007] The nut body has an internal threaded hole and a groove on its outer peripheral surface;

[0008] A support cylinder, one side of which is connected to the nut body, has a receiving cavity that communicates with the internal threaded hole and is used to accommodate the protruding part of a bolt that mates with the nut body;

[0009] A plastic outer shell is provided, which wraps around the outer wall of the support cylinder and the nut body, so that the side of the internal threaded hole facing away from the support cylinder is exposed. The plastic outer shell is provided with a protrusion that mates with the groove to fix it to the nut body.

[0010] By adopting the above technical solution, the support cylinder is the inner layer of the injection mold, which connects to the plastic outer shell after injection molding. The opening in the cavity can cover the protruding part after the bolt and nut body are mated. The design of the support cylinder protects the threaded connection of the bolt and nut body, preventing oily and alkaline substances from corroding the threads, thereby preventing corrosion at the connection between the nut body and the bolt. The plastic outer shell is formed by casting and cooling injection molding compound, and after molding, it covers the nut body. During injection molding, injection molding compound also flows into the groove of the nut body. The injection molding compound in the groove forms the protrusion of the plastic outer shell, and the protrusion mates with the groove of the nut body to strengthen the connection between the two and prevent them from falling off. The plastic outer shell protects the protruding parts of the nut and bolt, and is also more corrosion-resistant than the nut. The plastic outer shell and the support cylinder cover the outside of the nut, thus providing a corrosion-resistant oil pipeline nut.

[0011] Optionally, the nut body has an annular groove on the side facing the support cylinder, the annular groove is coaxial with the internal thread hole, and the support cylinder is engaged in the annular groove.

[0012] By adopting the above technical solution, it is not necessary to manufacture the support cylinder and the nut body as a single unit. The support cylinder and the annular groove are snapped together, allowing for the replacement of support cylinders with different depths to fit any nut body, thus enhancing the product's versatility. Furthermore, the annular groove also positions the support cylinder, ensuring that the support cylinder and the internal thread hole of the nut body are on the same axis, thereby facilitating the injection molding production of this type of nut.

[0013] Second aspect

[0014] This application provides an oil pipeline nut forming device, which includes:

[0015] An inner mold, which is cylindrical and has a receiving cavity, is used to install on the end face of the nut body so that the receiving cavity communicates with the internal threaded hole of the nut body;

[0016] An outer mold, which is cylindrical in shape, has a hexagonal prism-shaped opening at one end. The outer mold is used to wrap around the outer side of the inner mold and the nut body. An injection cavity is formed between the outer mold, the inner mold, and the nut body. The injection cavity is used to contain the injection-molded material.

[0017] By adopting the above technical solution, the support cylinder serves as the inner mold, which, together with the outer mold, forms the mold for injection molding. After the injection molding compound is injected from the injection cavity, it cools to form a plastic outer shell. After the plastic outer shell cools, the outer mold is removed, and a corrosion-resistant nut for oil pipelines is thus produced. By employing the above solution, the effect of producing a corrosion-resistant nut for oil pipelines is achieved.

[0018] Optionally, the outer mold has an injection port for injecting molding compound into the injection cavity, and the injection port is located at one end of the outer mold that is sealed.

[0019] By adopting the above technical solution, the opening of the inner mold is set towards the ground. Before injection molding begins, one side of the inner mold is engaged into the annular groove of the nut body. The injection port is located on the side of the outer mold away from the nut body, which facilitates the injection of the injection colloid, thereby achieving the effect of conveniently producing corrosion-resistant nuts for oil pipelines.

[0020] Optionally, the outer mold further includes a feed pipe, which is connected to the injection port.

[0021] By adopting the above technical solution, a margin of plastic material is provided for injection molding. When the injection molding material shrinks due to cooling, the injection molding material in the feed tube can compensate for the loss caused by the shrinkage of the injection molding material in the mold, thereby achieving a better injection molding effect.

[0022] Optionally, a clamping device is also included, wherein the gap between the open ends of the outer mold and the inner mold forms the injection port, and the clamping device has a force-applying part for extending from the internal threaded hole into the inner mold to fix the inner mold to the outer mold.

[0023] By adopting the above technical solution, the opening direction of the inner mold is set away from the ground, and the force-applying part of the clamping device applies radial force to the support cylinder, increasing the friction between the support cylinder and the nut body, so that the inner mold is fixed in the outer mold, thereby achieving the effect of facilitating the production of corrosion-resistant nuts for oil pipelines.

[0024] Optionally, the clamping device includes:

[0025] An inflation tube, one end of which is connected to an inflation device, is used to pass through the internal threaded hole;

[0026] An airbag is connected to the inflation tube. When the airbag is not inflated, it can pass through the internal threaded hole. The airbag is fixedly connected to the end of the inflation tube away from the inflation device. When the airbag is inflated, it fixes the inner mold inside the outer mold.

[0027] By employing the above technical solution, an airbag, an inflation tube, and an inflation device are used to apply radial force to the support cylinder. Gas from the inflation device passes through the inflation tube and the internal threaded hole into the airbag. The expansion force of the gas in the airbag applies radial force to the support cylinder, causing the sidewall of the support cylinder to clamp the annular groove, thereby clamping the support cylinder and preventing the injection molding cylinder from detaching and affecting the injection molding process. This achieves the effect of conveniently clamping the support cylinder.

[0028] Optionally, the clamping device includes:

[0029] The mounting plate has multiple guide grooves arranged in an array around its geometric center, and the mounting plate can pass through the internal threaded hole;

[0030] A drive motor having a drive shaft that slides through the mounting plate;

[0031] A drive gear is fixedly connected to the end of the drive shaft away from the drive motor, and the drive gear is rotatably connected to the mounting plate;

[0032] Driven gear, which meshes with the driving gear, and is concentrically rotatably connected to the mounting plate. The driven gear has multiple limiting grooves arrayed around its tooth center as a reference. A reference circle is provided at the center of the driven gear, and the extension direction of the limiting grooves is consistent with the involute direction of the reference circle.

[0033] Multiple guide blocks, each guide block being provided with a guide post, the guide post being slidably engaged with the limiting slide groove, the multiple guide blocks being engaged in multiple guide grooves and slidably engaged with the multiple guide grooves;

[0034] The rotation of the drive shaft drives the drive gear and the driven gear to rotate, thereby causing each guide block to slide along the guide groove.

[0035] By adopting the above technical solution, the drive shaft, drive gear, driven gear, and mounting plate are used to drive multiple guide blocks to apply radial force to the support cylinder, thereby causing the side wall of the support cylinder to clamp the annular groove, thus clamping the support cylinder and preventing the injection cylinder from falling off and affecting the injection molding, thereby achieving the effect of conveniently clamping the support cylinder.

[0036] Optionally, a water cooling device is also included, which is disposed on the outer wall of the outer mold.

[0037] By adopting the above technical solution, a water-cooling device is used for cooling plastic colloids during molding. The water-cooling device achieves rapid cooling, thereby greatly improving the production efficiency of plastic colloid cooling and molding, and thus accelerating the setting of nuts.

[0038] Thirdly, this application provides a method for manufacturing oil pipeline nuts, which utilizes an oil pipeline nut forming apparatus and includes the following steps:

[0039] Grooving: A groove is made on the outer peripheral wall of the nut body for fastening;

[0040] Placement of mold: Place the inner mold on the end face of the nut body, and fix the nut body and the inner mold in the outer mold to form an injection cavity;

[0041] Injection molding: Injecting the injection molding compound into the injection cavity;

[0042] Remove the outer mold: After the injected molten material cools and forms a plastic shell, remove the outer mold.

[0043] By adopting the above technical solution, the purpose of injection molding a type of oil pipeline nut can be achieved.

[0044] In summary, this application includes at least one of the following beneficial technical effects:

[0045] 1. A corrosion-resistant oil pipeline nut is provided by setting a plastic outer shell, a support cylinder, and a nut body;

[0046] 2. By opening an annular groove, it is possible to not only eliminate the need to manufacture the support cylinder and the nut body as a single unit, but also to facilitate the positioning of the support cylinder and the nut body;

[0047] 3. By setting up an inner mold, an outer mold, and an injection molding compound, a corrosion-resistant nut for oil pipelines was produced;

[0048] 4. By using different clamping devices, it is possible to facilitate the production of corrosion-resistant nuts for oil pipelines;

[0049] 5. By setting up the feed pipe, a margin is provided for injection molding;

[0050] 6. By installing a water cooling device, the efficiency of injection molding production is accelerated;

[0051] 7. By providing a method for manufacturing oil pipeline nuts, it is convenient to produce a corrosion-resistant oil pipeline nut. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the overall structure of an oil pipeline nut according to this application;

[0053] Figure 2 This is a half-sectional structural diagram of an oil pipeline nut according to this application;

[0054] Figure 3 This is a half-sectional structural diagram of Embodiment 1 of this application;

[0055] Figure 4 This is a half-sectional structural diagram of Embodiment 2 of this application;

[0056] Figure 5 This is a half-sectional structural diagram of Embodiment 3 of this application;

[0057] Figure 6 This is a schematic diagram of the clamping device structure of Embodiment 3 of this application.

[0058] In the diagram, 1. Nut body; 11. Internal threaded hole; 12. Groove; 13. Annular groove; 2. Support cylinder; 21. Receiving cavity; 3. Plastic outer shell; 4. Inner mold; 5. Outer mold; 51. Injection cavity; 511. Injection port; 52. Feed pipe; 6. Clamping device; 61. Inflation pipe; 62. Inflation equipment; 63. Mounting plate; 631. Guide groove; 64. Drive motor; 65. Drive gear; 66. Driven gear; 661. Limiting slide; 67. Guide block; 671. Guide post; 7. Water cooling device; 8. Worktable. Detailed Implementation

[0059] The following is in conjunction with the appendix Figure 1 -Appendix Figure 6 This application will be described in further detail below.

[0060] First aspect

[0061] Reference Figure 1 and Figure 2 An oil pipeline nut includes a nut body 1, a support cylinder 2, and a plastic outer shell 3.

[0062] The nut body 1 has an internal threaded hole 11, and a groove 12 is formed on the side away from the internal threaded hole 11. The nut body 1 can be a cylinder or a hexagonal prism; there are no restrictions on the external shape of the nut body 1. In addition, an annular groove 13 is formed on the upper side of the nut body 1. The annular groove 13 is coaxially arranged with the internal threaded hole 11, and the support cylinder 2 can be snapped into the annular groove 13. Since the protruding part of the bolt that mates with the nut body 1 has different lengths, the required cylinder depth of the support cylinder 2 is also different. By snapping the support cylinder 2 and the annular groove 13 together, support cylinders 2 with different cylinder depths can be replaced to fit any nut body 1, making the product more versatile. In addition, the annular groove 13 can also position the support cylinder 2, so that the support cylinder 2 is on the same axis as the internal threaded hole 11 of the nut body 1. The design of the annular groove 13 also eliminates the need to manufacture the support cylinder 2 and the nut body 1 as a single piece, making actual production more convenient.

[0063] The lower end of the support cylinder 2 has an opening on one side that connects to the nut body 1. The support cylinder 2 is the inner layer of the injection mold and connects to the plastic outer shell 3 after injection molding. A receiving cavity 21 is provided on one side of the opening, which communicates with the internal threaded hole 11 to accommodate the protruding part after the bolt and nut body 1 are engaged. The design of the support cylinder 2 protects the threaded connection between the bolt and the nut body 1, preventing oily and alkaline substances from corroding the threads, thereby preventing the connection between the nut body 1 and the bolt from rotting.

[0064] The plastic outer shell 3 is formed by casting and cooling injection molding compound, and after molding, it wraps around the outer wall of the support cylinder 2 and the nut body 1. Furthermore, the composition of the injection molding compound can be flexibly selected according to different environments. For example, if the environment has excessive alkaline substances, an alkali-resistant injection molding compound can be selected. The end of the plastic outer shell 3 near the nut body 1 is hexagonal prism-shaped, exposing the side of the internal threaded hole 11 facing away from the support cylinder 2. Simultaneously, protrusions that mate with the groove 12 are formed on the plastic outer shell 3. During injection molding, injection molding compound also flows into the groove 12 of the nut body 1. The injection molding compound in the groove 12 forms the protrusions of the plastic outer shell 3, and the protrusions, mate with the groove 12 of the nut body 1, reinforcing the connection between the two and preventing detachment. The plastic outer shell 3 is more corrosion-resistant than a steel nut, protecting the protruding parts of the nut and bolt. The cost of the plastic outer shell 3 is lower than that of a rigid shell or rigid protective sleeve. If the nut were made entirely of steel, it would be a waste of steel resources. Traditionally, to prevent corrosion, a protective sleeve is usually placed directly on the nut, leaving a gap between the sleeve and the nut. Oily or alkaline substances may seep into this gap and corrode the nut. The plastic outer shell is connected to the nut body 1 via injection-molded protrusions and grooves 12, virtually eliminating gaps and preventing corrosion of the nut by oily or alkaline substances in the oil pipeline environment.

[0065] Second aspect

[0066] Example 1:

[0067] Reference Figure 3 An oil pipeline nut forming device includes an inner mold 4 and an outer mold 5, used to manufacture the aforementioned oil pipeline nuts.

[0068] The inner mold 4 is a support cylinder 2 in the aforementioned oil pipeline nut, which can be installed on the nut body 1 through the annular groove 13, so that the receiving cavity 21 communicates with the internal threaded hole 11. The inner mold 4 is not removed after injection molding and is combined with the plastic outer shell 3 (in conjunction with the plastic outer shell 3). Figure 2 The above-mentioned oil pipeline nut is composed of the nut body 1 and the nut body 2.

[0069] The outer mold 5 is hexagonal prism-shaped at one end near the nut body 1, forming an injection cavity 51 between the outer mold 5, the inner mold 4, and the nut body 1. The injection molding compound is a high-temperature colloid that can form a plastic shell 3 after cooling. An injection port 511 is also provided on the top of the outer mold 5 (the side of the outer mold 5 away from the nut body 1), through which the injection molding compound is injected into the injection cavity 51.

[0070] The outer mold 5 also includes a feed pipe 52, which has a feed channel that connects to the injection port 511. The injection molding compound shrinks upon cooling. If only a volume of injection molding compound equal to the volume of the injection cavity 51 between the inner mold 4, the nut body 1, and the outer mold 5 is injected, the shrinkage after cooling will result in incomplete molding of the plastic outer shell 3. Therefore, more injection molding compound can be added. However, if the first injection molding compound cools before the next injection, a cold gap may appear due to the inconsistent injection times. The feed pipe 52 avoids this by pre-filling the feed pipe with the injection molding compound, providing a margin for the injection process. When the injection molding compound shrinks, the compound in the feed pipe 52 can compensate for the shrinkage within the mold, thus achieving a better injection molding effect.

[0071] The implementation principle of this embodiment is as follows:

[0072] Place the nut body 1 on the workbench 8, with the side having the annular groove 13 facing upwards. Install the inner mold 4 and snap it into the annular groove 13. Then, fit the outer mold 5 around the inner mold 4 and the outer wall of the nut body 1. Use a clamping device to hold the outer mold 5 on the workbench 8, ensuring a seal between the outer mold 5 and the workbench 8. Inject injection molding compound into the feed pipe 52. The injection molding compound is a gel-like substance. After entering the injection cavity 51, it flows into the groove 12 of the nut body 1. After cooling, it forms a protrusion that engages with the groove 12 of the nut body 1. After the injection molding compound cools and forms a plastic outer shell 3, remove the outer mold 5. A corrosion-resistant nut for oil pipelines is now produced.

[0073] Example 2:

[0074] Reference Figure 4 An oil pipeline nut forming device is generally the same as that in Example 1, except that the position of the injection port 511 is different, as are the water cooling device 7, the clamping device 6 and the placement of the mold.

[0075] The gap between the open ends of the outer mold 5 and the inner mold 4 forms the injection port 511.

[0076] The clamping device 6 has a force-applying part that extends from the internal threaded hole 11 into the inner mold 4 to fix the support cylinder 2 within the annular groove 13 of the nut body 1. The force-applying part of the clamping device 6 applies a radial force to the inner mold 4, causing the sidewall of the inner mold 4 to abut against the inner wall of the annular groove 13, increasing the friction between the inner mold 4 and the nut body 1. This fixes the inner mold 4 within the outer mold 5, preventing the support cylinder 2 from falling off under the action of the clamping device 6. Furthermore, the opening of the inner mold 4 faces away from the ground, allowing for better positioning of the inner mold 4 relative to the outer mold 5, thus facilitating the production of corrosion-resistant nuts for oil pipelines.

[0077] In this embodiment, the clamping device 6 consists of an inflation tube 61 and an airbag. The inflation tube 61 passes through the internal threaded hole 11, with its upper end connected to the inflation device 62 and its lower end connected to the airbag. The airbag, in its uninflated state, can pass through the internal threaded hole 11. After the airbag is placed into the receiving cavity 21, it is inflated using the inflation device 62. The gas in the inflation device 62 passes through the inflation tube 61 and the internal threaded hole 11, entering the airbag. The airbag, under the expansion force of the gas, exerts force on the inner mold 4, causing the sidewall of the inner mold 4 to clamp the annular groove 13, thereby expanding and fixing the inner mold 4 within the annular groove 13 of the nut body 1, preventing the inner mold 4 from falling off and affecting injection molding.

[0078] A water-cooling device 7 is installed on the outer wall of the outer mold 5 for cooling the plastic colloid during molding. A support block is provided at the bottom of the water-cooling device 7 to support the molding device. The water-cooling device 7 accelerates the setting of the plastic shell 3, thereby greatly improving the production efficiency of plastic colloid cooling and molding.

[0079] The implementation principle of this embodiment is as follows:

[0080] First, the outer mold 5 is placed on the water-cooling device 7, and then the inner mold 4 is snapped into the annular groove 13 of the nut body 1. Next, the inner mold 4 is installed and secured using an airbag and inflation device 62. The uninflated airbag is inserted into the receiving cavity 21 through the internal threaded hole 11, and then the airbag is inflated, causing it to expand and fix the inner mold 4 in the annular groove 13. Then, injection molding compound is injected into the injection port 511. The injection molding compound is a gel-like substance that, after entering the injection cavity 51, flows into the groove 12 of the nut body 1. After cooling, it forms a protrusion that engages with the groove 12 of the nut body 1. Finally, after the injection molding compound cools and forms a plastic outer shell 3 (not shown in the figure), the outer mold 5 is removed and deburred. A corrosion-resistant nut for oil pipelines is thus produced.

[0081] Example 3:

[0082] Reference Figure 5 and Figure 6An oil pipeline nut forming device is generally the same as that in Example 2, except that the clamping device 6 is different.

[0083] The clamping device 6 includes: a mounting plate 63, a drive motor 64, a drive gear 65, a driven gear 66, and a guide block 67.

[0084] The mounting plate 63 has multiple guide grooves 631 arranged radially around its geometric center (center). Guide blocks 67 are installed within each guide groove 631, and these guide blocks 67 slide within the guide grooves 631. The mounting plate 63 can pass through the internal threaded hole 11 and enter the receiving cavity 21. The drive shaft is fixedly connected to the drive gear 65 and slides through the mounting plate 63. A driven gear 66 is fixedly connected to the mounting plate 63, meshing with the drive gear 65. Multiple limiting grooves 661 are arranged in an array around the tooth center. A reference circle is located at the center of the driven gear 66. The extension direction of the limiting grooves 661 is consistent with the involute direction of the reference circle. Guide posts 671 are installed within the limiting grooves 661, and these guide posts 671 are fixedly connected to the guide blocks 67. The drive shaft is connected to the drive motor 64. When the drive motor 64 applies rotational force to the drive shaft, causing the drive gear 65 to rotate, the guide post 671 slides within the limiting slide groove 661, driving the guide block 67 to slide back and forth within the guide groove 631. Specifically, the drive shaft drives the drive gear 65 to rotate, which in turn drives the driven gear 66 to rotate. The driven gear 66 then drives the guide post 671 on the guide block 67 to slide within the limiting slide groove 661. The guide post 671 then drives the guide block 67 to slide within the guide groove 631 on the disc. The guide block 67 can apply a radial force to the inner mold 4, causing the side wall of the inner mold 4 to clamp the annular groove 13, thereby clamping the inner mold 4 and preventing the injection cylinder from falling off and affecting the injection molding process, thus achieving the effect of conveniently clamping the inner mold 4.

[0085] Third aspect

[0086] A method for manufacturing oil pipeline nuts, utilizing an oil pipeline nut forming apparatus according to Example 1, Example 2, or Example 3, includes the following steps:

[0087] Grooving: A groove 12 for fastening is made on the outer peripheral wall of the nut body 1;

[0088] Placement of mold: Place the support cylinder 2 on the end face of the nut body 1, and fix the nut body 1 and the support cylinder 2 in the outer mold 5 to form an injection cavity 51;

[0089] Specifically, in Embodiment 1, the nut body 1 is placed on the workbench 8 with the side having the annular groove 13 facing upwards, and the inner mold 4 is installed. The inner mold 4 is snapped into the annular groove 13, and then the outer mold 5 is fitted and wrapped around the inner mold 4 and the outer wall of the nut body 1. In Embodiments 2 and 3, the outer mold 5 is first placed on the water cooling device 7, and then the inner mold 4 is snapped into the annular groove 13 of the nut body 1. Then, the force-applying part of the clamping device 6 applies force to the support cylinder 2, so that the inner mold 4 is fixed inside the outer mold 5.

[0090] Injection molding: Injecting the injection molding compound into the injection cavity 51;

[0091] Remove the outer mold 5: After the plastic shell 3 has cooled, remove the outer mold 5 and remove any excess burrs.

[0092] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A device for forming oil pipeline nuts, characterized in that, include: The inner mold (4) is cylindrical and has a receiving cavity (21) for installation on the end face of the nut body (1) so that the receiving cavity (21) communicates with the internal thread hole (11) of the nut body (1); An outer mold (5) is cylindrical, with one open end of the outer mold (5) being hexagonal prism-shaped. The outer mold (5) is used to wrap around the outer side of the inner mold (4) and the nut body (1). An injection cavity (51) is formed between the outer mold (5), the inner mold (4), and the nut body (1). The injection cavity (51) is used to contain the injection molding compound. It also includes a clamping device (6), the gap between the outer mold (5) and the inner mold (4) having an open end forms an injection port (511), the clamping device (6) has a force-applying part, the force-applying part is used to extend from the internal thread hole (11) into the inner mold (4) to fix the inner mold (4) into the outer mold (5); The clamping device (6) includes: An inflation tube (61) is provided, one end of which is connected to an inflation device (62), and the inflation tube (61) is used to pass through the internal threaded hole (11). An airbag is connected to the inflation tube (61). When the airbag is not inflated, it can pass through the internal thread hole (11). The airbag is fixedly connected to the end of the inflation tube (61) away from the inflation device (62). When the airbag is inflated, it fixes the inner mold (4) inside the outer mold (5). Or the clamping device (6) may include: Mounting disc (63) has multiple guide grooves (631) arranged in an array with the geometric center as the center, and the mounting disc (63) can pass through the internal threaded hole (11). A drive motor (64) has a drive shaft that slides through the mounting plate (63); The drive gear (65) is fixedly connected to the end of the drive shaft away from the drive motor (64), and the drive gear (65) is rotatably connected to the mounting plate (63); Driven gear (66), which meshes with the driving gear (65), and is concentrically connected to the mounting plate (63). The driven gear (66) has multiple limiting grooves (661) arrayed with the tooth center as the reference. The center of the driven gear (66) is provided with a reference circle. The extension direction of the limiting grooves (661) is consistent with the involute direction of the reference circle. Multiple guide blocks (67) are provided with guide posts (671), the guide posts (671) are slidably engaged with the limiting slide groove (661), and the multiple guide blocks (67) are engaged in multiple guide grooves (631) and slidably engaged with the multiple guide grooves (631); The rotation of the drive shaft causes the drive gear (65) and the driven gear (66) to rotate, thereby causing each of the guide blocks (67) to slide along the guide groove (631).

2. The oil pipeline nut forming device according to claim 1, characterized in that, The outer mold (5) has an injection port (511) for injecting the injection colloid into the injection cavity (51). The injection port (511) is located at one end of the outer mold (5) that is sealed.

3. The oil pipeline nut forming device according to claim 2, characterized in that, The outer mold (5) also includes a feed pipe (52), which is connected to the injection port (511).

4. The oil pipeline nut forming device according to claim 1, characterized in that, It also includes a water cooling device (7), which is disposed on the outer wall of the outer mold (5).

5. A method for manufacturing an oil pipeline nut, characterized in that, The oil pipeline nut forming apparatus according to any one of claims 1-4 includes the following steps: Grooving: A groove (12) for fastening is made on the outer peripheral wall of the nut body (1); Place the mold: Place the inner mold (4) on the end face of the nut body (1), and fix the nut body (1) and the inner mold (4) in the outer mold (5) to form an injection cavity (51). Injection molding: Injecting the injection molding compound into the injection cavity (51); Remove the outer mold (5): After the injected colloid cools and forms a plastic shell (3), remove the outer mold (5).

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