Pipeline connecting structure and pipeline connecting piece

Abstract

The pipeline connecting structure comprises a main pipe, a lining arranged on the main pipe in a sleeving mode and a threaded sleeve used for attaching the main pipe to a pipe joint, internal threads are arranged on the inner side wall of one end of the threaded sleeve, and a through hole allowing the main pipe to pass through is formed in the middle of the end face of the other end of the threaded sleeve. A convex ring capable of preventing the main pipe from completely penetrating through the through hole is arranged on the shaft side surface at one end of the main pipe; the lining comprises a first end capable of abutting between the inner end face of the threaded sleeve and the end face of the convex ring and a second end capable of abutting between the inner ring of the through hole and the side wall of the main pipe shaft. The overall rigidity of the connecting position of the threaded sleeve and the pipeline is improved, the position, where vibration easily occurs, between the threaded sleeve and the protruding ring is transferred backwards from an original weak point, relative vibration does not easily occur between the main pipe and the threaded sleeve after installation, the connecting strength is higher, the situation of metal fatigue fracture is not likely to occur, and the service life of the main pipe and the pipeline is prolonged. The anti-seismic performance of the whole pipeline conveying system is greatly improved, meanwhile, the metal lining is not prone to damage, and the service life is greatly prolonged.

Description

Technical Field

[0001] This invention relates to the field of pipe connection technology, and more particularly to pipe connection structures and pipe connectors. Background Technology

[0002] Media transportation is inseparable from pipelines, and different media with different properties are generally transported through different pipelines. There are many common pipeline connection methods, such as threaded, flanged, welded, press-fit, and grooved connections. Different application scenarios and media require different connection methods.

[0003] Among these, the simplest structural solution that can be assembled without the aid of additional tools is the threaded method: the ends of two pipes are directly connected together by threads, and a sealing ring is installed at the connection to ensure a tight seal.

[0004] Based on this, there are many existing thread design methods for pipes. For example, internal or external threads can be set on joints with different diameters to splice two pipes of the same diameter together. There is also a screw sleeve type solution, which involves putting a screw sleeve on the outer wall of the pipe and setting a protrusion at the end of the pipe to prevent the screw sleeve from coming off. After placing the sealing ring on the pipe joint, the screw sleeve can be tightened.

[0005] Screw-fit connections are typically used in scenarios requiring quick assembly and disassembly, such as industrial pump stations. However, this type of connection has a drawback: when used for high-pressure media transport, the pipeline experiences significant vibration, which can easily cause vibration at the pipe connection. Over time, the pressure between the pipe and the screw-fit can lead to material cracking, resulting in direct leakage at the pipe connection. This is a situation that many consumers have encountered.

[0006] To solve this problem, the only option is usually to replace the entire pipe and bolt sleeve. This may not be expensive for ordinary consumers, but it is much more expensive in industrial settings. Furthermore, the pressure of the medium in industrial settings is often much higher, and the requirements for sealing are also much stricter.

[0007] Therefore, this application proposes a pipe connection structure and pipe connector with stronger seismic resistance. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a pipe connection structure. This structure improves the overall rigidity of the connection between the main pipe and the threaded sleeve by filling the space between the main pipe and the threaded sleeve with a bushing. It also shifts the location where vibration is likely to occur between the threaded sleeve and the convex ring from the original weak point to the rear. This results in less relative vibration between the installed main pipe and the threaded sleeve, higher connection strength, and less likelihood of metal fatigue fracture. This significantly improves the seismic performance of the entire pipeline transportation system. At the same time, the metal bushing is less prone to damage, greatly extending its service life. Even if it is damaged, only the bushing needs to be replaced, significantly reducing maintenance costs. The assembly and maintenance operations are also more convenient.

[0009] On the one hand, in order to achieve the above objectives, the present invention provides the following technical solution: A pipe connection structure includes a main pipe, a bushing fitted onto the main pipe, and a threaded sleeve for attaching the main pipe to a pipe fitting. The inner wall of one end of the threaded sleeve has an internal thread, and the center of the end face of the other end of the threaded sleeve has a through hole for the main pipe to pass through. The axial side of one end of the main pipe has a protruding ring to prevent the main pipe from completely passing through the through hole. The bushing includes: The first end can abut between the inner end face of the threaded sleeve and the end face of the convex ring; The second end can abut between the inner ring of the through hole and the side wall of the main shaft.

[0010] The above structure, by filling the gap between the main pipe and the threaded sleeve with a bushing, improves the overall rigidity of the connection between the threaded sleeve and the pipe. It also shifts the location where vibration is likely to occur between the threaded sleeve and the convex ring from the original weak point to the rear. This makes it less prone to relative vibration between the installed main pipe and the threaded sleeve, and the connection strength is higher, making it less likely to cause metal fatigue fracture. This significantly improves the seismic performance of the entire pipeline transportation system. At the same time, the metal bushing is not easily damaged, and its service life is greatly extended. Even if it is damaged, only the bushing needs to be replaced, which greatly reduces maintenance costs. The assembly and maintenance operations are also more convenient.

[0011] Preferably, the convex ring has a first chamfer at one end near the through hole to fit the shaft end face of the first end, and the through hole has a second chamfer on the edge near the internal thread to fit the other shaft end face of the first end, wherein the taper of the first chamfer is less than or equal to the taper of the second chamfer.

[0012] Preferably, the through hole is a tapered hole that extends away from the direction of the internal thread, and the tapering degree of the second end is less than or equal to the tapering degree of the tapered hole.

[0013] Preferably, the taper of the first chamfer is equal to the taper of the second chamfer, and the taper of the second end is equal to the taper of the tapered hole.

[0014] The above structure allows the bushing to form an axial and radial interference fit between the bushing and the main pipe when the threaded sleeve is tightened. At the same time, it provides greater friction and expansion force in the axial and radial directions, making it difficult for the bushing or the main pipe to loosen under tension. Furthermore, the stress distribution is relatively uniform, which can better transmit vibration energy and reduce the loss of vibration energy in this pipe connection structure. Therefore, it is difficult to generate vibration, which greatly improves the seismic performance of this connection structure.

[0015] Preferably, the difference between the maximum diameter of the tapered hole and the outer diameter of the main pipe is less than the axial thickness of the first end.

[0016] The above structure provides more axial deformation space for the bushing, making it more suitable for applications with more frequent axial vibration forces.

[0017] Preferably, the end of the convex ring away from the through hole is provided with a third chamfer with a tapering direction opposite to that of the first chamfer, and the tapering degree of the third chamfer is less than that of the first chamfer.

[0018] Preferably, the middle of the tapered surface of the third chamfer is bulging.

[0019] Preferably, the outer diameter of the convex ring is greater than the maximum diameter of the third chamfer.

[0020] The above structure can accommodate pipe fittings with different apertures, ensuring the structural stability of the convex ring and thus ensuring reliable seismic performance.

[0021] Preferably, the bushing has an opening extending through the first end and the second end, allowing the bushing to be unfolded into a sheet-like structure.

[0022] The above structure makes assembly easier and results in a better fit between the assembled bushing and the main pipe, as well as stronger shock resistance.

[0023] Preferably, the outer edge of the end face of the convex ring near the through hole is further provided with a fourth chamfer, and the taper of the fourth chamfer is greater than that of the first chamfer.

[0024] The above structure can support the bushing, not only limiting the tendency of the bushing to unfold into a sheet shape when it is not fully attached to the surface of the main pipe, but also dispersing the stress on the first edge of the bushing when it is pressed, making it more difficult for the bushing to loosen and improving its shock resistance. It also has a guiding function, preventing the main pipe from bumping into the end face or internal thread of the threaded bushing during insertion, and avoiding the reduction of shock resistance due to surface wear of the first chamfer.

[0025] Preferably, the bushing is made of metal.

[0026] The above structure is suitable for scenarios with high seismic performance requirements.

[0027] On the other hand, in order to achieve the above objectives, the present invention also provides the following technical solution: The pipe connector includes the aforementioned pipe connection structure and also includes a pipe fitting, wherein the pipe fitting includes at least one of an N-type connector and a valve, wherein at least one end of the pipe fitting is provided with an external thread that mates with an internal thread, and the inner diameter of the pipe fitting is smaller than the outer diameter of the convex ring.

[0028] Compared with the prior art, the beneficial effects of this invention are as follows: by filling the gap between the main pipe and the threaded sleeve with a bushing, the overall rigidity of the threaded sleeve and the pipe at the connection position is improved, and the position where vibration is prone to occur between the threaded sleeve and the convex ring is shifted from the original weak point to the rear. This makes it less likely for relative vibration to occur between the installed main pipe and the threaded sleeve, and the connection strength is higher, making it less likely for metal fatigue fracture to occur. This greatly improves the seismic performance of the entire pipeline transportation system. At the same time, the metal bushing is not easily damaged, and its service life is greatly extended. Even if it is damaged, only the bushing needs to be replaced, which greatly reduces maintenance costs. The assembly and maintenance operations are also more convenient. Attached Figure Description

[0029] Figure 1 This is an exploded structural diagram of the pipe connector proposed in this invention; Figure 2 This is a three-dimensional sectional view of the pipe connector proposed in this invention; Figure 3 For this Figure 2 The front view; Figure 4 This is an assembly drawing of the pipe connection structure proposed in this invention; Figure 5 This is a front view of the structure of the pipe connector with a large pipe joint diameter proposed in this invention; Figure 6 This is a front view of the structure of the pipe connector with a small orifice diameter in the pipe connector proposed in this invention; Figure 7 This is a schematic diagram of the bushing and main pipe in the pipe connection structure proposed in this invention, mainly showing the fourth chamfer; Figure 8 This is a perspective view of the bushing in the pipe connection structure proposed in this invention; Figure 9 This is the static stress analysis experiment report for the control group in Experiment Example 1. Figure 10 This is the simulation experiment static stress analysis report for the experimental group in Experiment Example 1; Figure 11 This is a comparison diagram of the maximum displacement of the connector near the second end in the static stress analysis results of Experiment Example 1; Figure 12This is a comparison diagram of the stress in the connecting parts in the static stress analysis results of Experiment Example 1; Figure 13 The strain comparison diagram of the connecting parts in the static stress analysis results of Experiment Example 1 is shown. Figure 14 This is a schematic diagram of the installation process for Experiment Example 2.

[0030] In the picture: 1. Main pipe; 11. Convex ring; 111. First chamfer; 112. Third chamfer; 113. Fourth chamfer; 2. Bushing; 21. First end; 22. Second end; 3. Screw insert; 31. Internal thread; 32. Through hole; 321. Second chamfer; 322. Tapered hole; 4. Pipe fitting; 41. External thread. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Currently, pipe connections typically use threaded sleeves to meet the need for quick assembly and disassembly, such as in industrial pump stations. However, this connection structure relies on independent gaskets for sealing performance. But in scenarios involving high-pressure media transport, the pipes and pipe fittings are subjected to prolonged periods of significant vibration. Therefore, the connection point between the threaded sleeve and the pipe (i.e.,...) Figure 1 The convex ring 11 in the middle is subject to relative collision for a long time. The convex ring 11 is currently basically formed by cold extrusion. Although the strength is high, this process also makes the convex ring 11 brittle. Therefore, the connection between the threaded sleeve and the pipeline is prone to metal fatigue cracking under long-term vibration, which can lead to failure of the pipeline transportation system.

[0033] However, if the pipe fails, the entire pipe and pipe fittings must be replaced, which is costly and very cumbersome. Therefore, the following technical solution is proposed. The pipe fittings should be considered as common fittings in the field of threaded pipe connections, such as tees and valve fittings, with external threads at their ends.

[0034] The main pipe should be considered as the pipe to be connected. It must be made of rigid material to meet the basic requirements of pipe "connection". However, the specific material selection should not be restricted. It can be a steel pipe or a high-strength rigid non-metallic pipe. Therefore, the scope of protection of this technical solution covers various scenarios in the field of pipe connection technology.

[0035] Example 1: Please see Figure 1-4 The present invention provides the following technical solution: a pipe connection structure, including a main pipe 1, a bushing 2 sleeved on the main pipe 1, and a threaded sleeve 3 for attaching the main pipe 1 to a pipe joint 4. The bushing 2 is made of metal. The inner side wall of one end of the threaded sleeve 3 is provided with an internal thread 31. The middle of the end face of the other end of the threaded sleeve 3 is provided with a through hole 32 for the main pipe 1 to pass through. The axial side of one end of the main pipe 1 is provided with a protruding ring 11 that can prevent the main pipe 1 from completely passing through the through hole 32. The bushing 2 includes a first end 21 that abuts between the inner end face of the threaded sleeve 3 and the end face of the convex ring 11, and a second end 22 that abuts between the inner ring of the through hole 32 and the side wall of the main pipe 1.

[0036] As an optional implementation of the present invention, the bushing 2 is fitted onto the main pipe 1 from the end away from the convex ring 11, the main pipe 1 is connected from the open end of the threaded sleeve 3 (i.e. the end with the internal thread 31) and passes through the through hole 32, so that the first end 21 of the bushing 2 is clamped between the inner end face of the threaded sleeve 3 and the end face of the convex ring 11, and then the threaded sleeve 3 is tightened onto the external thread 41 of the pipe joint 4.

[0037] During the tightening process, the end of the pipe fitting 4 is connected to the inside of the open end of the threaded sleeve 3, so the end face of the pipe fitting 4 can abut against the end face of the convex ring 11 or the main pipe 1 (there is also a sealing ring between the pipe fitting 4 and the main pipe 1). During the continuous tightening process, the bushing 2 is subjected to both the thrust of the threaded sleeve 3 and the resistance of the main pipe 1.

[0038] As bushing 2 moves with main pipe 1, the second end 22 of bushing 2 first enters through hole 32, filling the space between main pipe 1 and the inner ring of through hole 32. Then, main pipe 1 drives bushing 2 to continue moving, and finally, the second end 22 of bushing 2 is clamped between the end face of convex ring 11 and the inner end face of threaded sleeve 3, filling the space between the end faces of convex ring 11 and threaded sleeve 3. Finally, when threaded sleeve 3 is fully tightened, the end face of pipe fitting 4 exerts a continuous clamping force on the end of main pipe 1 or the end of convex ring 11, forming a rigid whole at the connection point between threaded sleeve 3 and main pipe 1.

[0039] When transporting high-pressure media, there is long-term vibration in the pipeline. Therefore, the main pipe 1 or the threaded sleeve 3 will vibrate. Since the bushing 2 is made of metal, it has high strength, high shear resistance and high tensile strength, which can significantly reduce the relative vibration between the threaded sleeve 3 and the main pipe 1. Furthermore, the vibration point between the threaded sleeve 3 and the main pipe 1 is transferred from the original surface of the convex ring 11 to the surface of the bushing 2, that is, the vibration position has changed.

[0040] Therefore, the use of bushing 2 makes the assembly between threaded sleeve 3 and main pipe 1 more compact, and threaded sleeve 3 and main pipe 1 become a rigid whole, which improves the transmission of vibration force and makes it less likely for relative movement to occur. This makes it less likely for material deformation to occur between threaded sleeve 3 and main pipe 1. At the same time, compared with the original method where the convex ring 11 directly contacts the inner ring of threaded sleeve 3, the first end of bushing 2 fills the axial space between threaded sleeve 3 and convex ring 11, so the pressure point of threaded sleeve 3 on main pipe 1 is located on the surface of bushing 2, away from convex ring 11. Therefore, convex ring 11 will not be directly subjected to the pressure of threaded sleeve 3, and is therefore less likely to deform. Even if the material deforms after prolonged use, bushing 2 can be replaced directly.

[0041] In this technical solution, the metal bushing 2 primarily provides shock resistance, not sealing performance, when used for high-pressure media transportation. Of course, those skilled in the art can replace the bushing 2 with a soft, elastic material, or apply a soft, elastic material to the surface of the bushing 2 to achieve a certain degree of sealing, thus providing a multi-layer sealing effect. The through hole 32 on the threaded sleeve 3 can be formed by cold extrusion.

[0042] By using this method, the bushing 2 fills the gap between the main pipe 1 and the threaded sleeve 3, improving the overall rigidity of the threaded sleeve 3 and the main pipe 1 at the connection point. It also shifts the location where vibration is likely to occur between the threaded sleeve 3 and the convex ring 11 from the original weak point to the rear. This makes it less likely for relative vibration to occur between the installed main pipe 1 and the threaded sleeve 3, and the connection strength is higher, making it less likely for metal fatigue fracture to occur. This significantly improves the seismic performance of the entire pipeline transportation system. At the same time, the metal bushing is not easily damaged, and its service life is greatly extended. Even if it is damaged, only the bushing needs to be replaced, which greatly reduces maintenance costs. The assembly and maintenance operations are also more convenient.

[0043] Furthermore, for the material of bushing 2, those skilled in the art can also use other non-metallic materials with the above-mentioned properties as equivalent replacements, such as plastics with a relatively hard texture.

[0044] Example 2: Please see Figure 1-7The present invention provides the following technical solution: a pipe connection structure, including a main pipe 1, a bushing 2 sleeved on the main pipe 1, and a threaded sleeve 3 for attaching the main pipe 1 to a pipe joint 4. The bushing 2 is made of 316L stainless steel. The inner side wall of one end of the threaded sleeve 3 is provided with an internal thread 31. The middle of the end face of the other end of the threaded sleeve 3 is provided with a through hole 32 for the main pipe 1 to pass through. The axial side of one end of the main pipe 1 is provided with a protruding ring 11 that can prevent the main pipe 1 from completely passing through the through hole 32. The bushing 2 includes a first end 21 that can abut against the inner end face of the threaded sleeve 3 and the end face of the convex ring 11, and a second end 22 that can abut against the inner ring of the through hole 32 and the side wall of the main pipe 1 shaft. The convex ring 11 has a first chamfer 111 at one end near the through hole 32 to fit the shaft end face of the first end 21, and the through hole 32 has a second chamfer 321 at the edge near the internal thread 31 to fit the other shaft end face of the first end 21; the through hole 32 is a tapered hole 322 in the direction away from the internal thread 31; the tapering degree of the first chamfer 111 is equal to the tapering degree of the second chamfer 321, and the tapering degree of the second end 22 is equal to the tapering degree of the tapering hole 322.

[0045] As an optional implementation of the present invention, during the tightening of the threaded sleeve 3, the narrow end of the tapered hole 322 on the through hole 32 (i.e., the outermost part of the through hole 32) first contacts the axial side wall of the second end 22 of the bushing 2. At this time, the second chamfer 321 has not yet contacted the axial end face of the first end 21 of the bushing 2. During the continuous tightening process, the bushing 2 not only provides guidance for the insertion of the main pipe 1 into the through hole 32, but also receives pressure from the main pipe 1 and the through hole 32. When the axial end face of the first end 21 of the bushing 2 contacts the second chamfer 321, the bushing 2 forms an interference fit between the tapered hole 322 and the main pipe 1, so that the main pipe 1 and the tapered hole 322 have a large tight fit force. The main pipe 1 is radially held by the tapered hole 322 of the threaded sleeve 3, ensuring that the main pipe 1 is difficult to swing in the radial direction. When the shaft end face of the first end 21 of the bushing 2 contacts the second chamfer 321, the first chamfer 111 of the convex ring 11 on the main pipe 1 applies a clamping force to the other end face of the first end 21 of the bushing 2. Since the taper of the first chamfer 111 and the second chamfer 321 are equal, the first end 21 of the bushing 2 is simultaneously subjected to equal axial and radial forces from the first chamfer 111 and the second chamfer 321, resulting in a relatively uniform stress distribution and uniform elastic deformation (microscopic) of the bushing 2. After the tightening action stops, the bushing 2 has a large residual contact stress relative to the main pipe 1 and the threaded sleeve 3, resulting in a large static friction force on the contact surfaces of the bushing 2 and the steel pipe, and the bushing 2 and the threaded sleeve 3.

[0046] When a vibrational force originates from one end of the main pipe 1 or the other end of the connecting pipe head, any vibrational load attempting to cause relative sliding (axial or radial) between the main pipe 1 and the threaded sleeve 3 must first overcome this static friction. Because this friction is very large, relative sliding is impossible, thus achieving a locking effect. The vibrational energy is dissipated directly by the frictional force as heat. Furthermore, to loosen the threaded sleeve 3 or reduce its sealing performance is equivalent to applying a tensile force to one end of the main pipe 1 and the threaded sleeve 3. However, to pull the steel pipe out, the entire bushing 2 must "climb" out along the two conical surfaces, which requires overcoming enormous radial contraction and expansion forces, equivalent to reversing the interference fit, making it extremely difficult. Moreover, when there is no relative displacement, the bushing 2, the threaded sleeve 3, and the main pipe 1 form a rigid whole, and the internal stress distribution is relatively uniform. Therefore, most of the vibrational energy affects the whole formed by the bushing 2, the main pipe 1, and the threaded sleeve 3, rather than any individual component within it.

[0047] Of course, it is not easy to manufacture the first chamfer 111 and the second chamfer 321 with equal taper, as well as the second end 22 shaft side and the inner ring of the taper hole 322 with equal taper. On the basis of roughly ensuring that the taper is equal, it is sufficient to ensure that the taper of the first chamfer 111 is slightly smaller than the taper of the second chamfer 321, and the taper of the second end 22 is slightly smaller than the taper of the taper hole 322.

[0048] Compared to Example 1, this example further specifies the material of the screw sleeve 3 - it is made of 316L stainless steel. The advantage is that it has excellent high temperature resistance, low temperature resistance and corrosion resistance, and can be used in different industrial environments and can adapt to the transportation of various media.

[0049] Since common industrial pipes are generally made of carbon steel (20#, 45# steel), stainless steel (316L, 304), and PVC, 316L stainless steel generally has a higher strength than common pipes, or at least can be comparable to these pipes, but will not be lower than these pipes, thus meeting the dual requirements of corrosion resistance and strength.

[0050] By adopting this implementation method, when tightening the threaded sleeve 3, the bushing 2 can form an axial and radial interference fit between the threaded sleeve 3 and the main pipe 1, while providing large friction and expansion forces in the axial and radial directions. This makes it difficult for the threaded sleeve 3 or the main pipe 1 to loosen under tension, and the stress distribution is relatively uniform. It can better transmit vibration energy and reduce the loss of vibration energy in this pipe connection structure, so it is difficult to generate vibration and greatly improves the seismic performance of this connection structure.

[0051] Furthermore, the difference between the maximum diameter of the tapered hole 322 and the outer diameter of the main pipe 1 is less than the axial thickness of the first end 21.

[0052] As an optional implementation of the present invention, since the clamping force of the bushing 2 depends on the thread fit between the threaded sleeve 3 and the connecting head, for the first end 21, in order to ensure that the stress distribution of the bushing 2 after being compressed is relatively uniform, the thickness of the first end 21 of the bushing 2 cannot be too thin. In addition, the larger the axial thickness of the first end 21, the more deformation space it can provide, and therefore it is more suitable for application in scenarios with more frequent axial vibration forces, such as suspended hoses.

[0053] Of course, those skilled in the art can also set the above scheme as the opposite relationship, that is, the difference between the maximum diameter of the tapered hole 322 and the outer diameter of the main pipe 1 is greater than the axial thickness of the first end 21, so that the bushing 2 can provide higher radial vibration resistance to adapt to scenarios with more frequent radial vibration.

[0054] Furthermore, since there are different types of pipe fittings 4 in the existing ones, some with large orifice diameters and some with small orifice diameters, the end face of the pipe fitting 4 with a slightly larger orifice diameter will abut against the convex ring 11 during assembly, while the pipe fitting 4 with a slightly smaller orifice diameter will abut directly against the end face of the main pipe 1 during assembly. Therefore, this technical solution needs to be discussed in a classified manner: ① The diameter of the hole in pipe fitting 4 is slightly larger: Specifically, the end of the convex ring 11 away from the through hole 32 is provided with a third chamfer 112 whose tapering direction is opposite to that of the first chamfer 111. The tapering degree of the third chamfer 112 is less than that of the first chamfer 111. The middle part of the tapering surface of the third chamfer 112 is bulging. The outer diameter of the convex ring 11 is greater than the maximum diameter of the third chamfer 112.

[0055] After the pipe fitting 4 is tightened, its end face extends between the main pipe 1 and the threaded sleeve 3 and abuts against the end face of the convex ring 11. At this time, the third chamfer 112 not only balances the force on the convex ring 11, but also serves as the snap-fit ​​position for the sealing gasket (i.e., the sealing ring). Since the third chamfer 112 also has a tapering degree and a bulge in the middle, it has two different tapering degrees. After installation, the snap-fit ​​effect is better and the sealing is more reliable.

[0056] ② The orifice diameter of pipe fitting 4 is slightly smaller: Specifically, the end of the convex ring 11 away from the through hole 32 is provided with a third chamfer 112 whose tapering direction is opposite to that of the first chamfer 111. The tapering degree of the third chamfer 112 is less than that of the first chamfer 111, and the outer diameter of the convex ring 11 is aligned with the maximum diameter of the third chamfer 112.

[0057] After the pipe fitting 4 is tightened, its end face directly abuts against the main pipe 1. At this time, because the convex ring 11 bears huge pressure from the end faces of the bushing 2 and the threaded sleeve 3, the setting of the third chamfer 112 is similar to the function of a "reinforcing rib", which can enhance the structural stability of the convex ring 11.

[0058] As an optional implementation of the present invention, the pipe fitting 4 can be adapted to different hole diameters, ensuring the structural stability of the convex ring 11 and thus ensuring reliable seismic performance.

[0059] The chamfer mentioned above can be a beveled chamfer, a rounded chamfer, or a combination of both. Similarly, the taper mentioned above can be linear, arc-shaped, or a combination of a straight line and a curve. This implementation does not impose any specific limitations on this.

[0060] Furthermore, such as Figure 8 As shown, the bushing 2 has an opening that passes through the first end 21 and the second end 22, so that the bushing 2 can be unfolded into a sheet-like structure.

[0061] As an optional implementation of the present invention, if the stainless steel bushing 2 is directly produced in the shape of a sleeve, then in order to ensure that it can be installed on the main pipe 1, a gap tolerance must be left between the bushing 2 and the main pipe 1 so that the bushing 2 can be smoothly fitted onto the main pipe 1. However, during pipe connection, plastic deformation of the surface of the bushing 2 may be caused, or the fit between the bushing 2 and the main pipe 1 may be insufficient, which would make it easier for relative vibration to occur. Therefore, this production method cannot be directly adopted.

[0062] Of course, shaping the bushing 2 into a sheet is also a common existing method, mainly because it makes assembly easier. In this technical solution, the assembled bushing 2 can also achieve a higher degree of fit with the main pipe 1, resulting in stronger seismic performance.

[0063] For the sheet-like shape of the bushing 2 before assembly, its edge can be a parallel curve or a straight line, or it can be a non-parallel line. This technical solution does not make specific limitations on this, but at least it should be ensured that when the bushing 2 is rolled up, the end with the larger diameter can always completely cover the axial side surface of the entire main tube 1.

[0064] Furthermore, a fourth chamfer 113 is provided on the outer edge of the end face of the convex ring 11 near the through hole 32, and the taper of the fourth chamfer 113 is greater than that of the first chamfer 111.

[0065] As an optional implementation of the present invention, since the first chamfer 111 serves to press the first end 21 of the bushing 2 on the convex ring 11, the processing requirements for the first chamfer 111 are actually quite high. However, at the beginning of assembly, the gap between the through hole 32 and the main pipe 1 is still relatively large, so it can be tilted, which leads to the problem that the first chamfer 111 may hit the edge of the open port of the threaded sleeve 3. However, the fourth chamfer 113 can play a protective and guiding role, not only making it less likely for the first chamfer 111 to hit the edge of the threaded sleeve 3, but also preventing the edge of the first chamfer 111 from contacting the surface of the internal thread 31 and causing wear when the main pipe 1 passes through the internal thread 31 of the threaded sleeve 3.

[0066] Furthermore, and more importantly, at the end of the tightening process of the sleeve 3, the radial component of the force exerted by the edge of the first chamfer 111 on the end face edge of the first end 21 of the bushing 2 is greater than the axial component, resulting in stress concentration. The edge of the first end 21 of the bushing 2 is prone to extend beyond the edge of the first chamfer 111 due to overtight thread assembly. Therefore, the fourth chamfer 113, with a greater taper than the first chamfer 111, can provide support, not only limiting the tendency of the bushing 2 to unfold into a sheet-like shape when it is not fully attached to the surface of the main pipe 1, but also dispersing the stress on the edge of the first end 21 of the bushing 2 when it is tightened, making it more difficult for the bushing 2 to loosen, thus improving its shock resistance.

[0067] Example 3: Please see Figure 1-7 The present invention provides the following technical solution: a pipe connection structure, including a main pipe 1, a bushing 2 sleeved on the main pipe 1, and a threaded sleeve 3 for attaching the main pipe 1 to a pipe joint 4. The inner side wall of one end of the threaded sleeve 3 is provided with an internal thread 31, and the middle of the end face of the other end of the threaded sleeve 3 is provided with a through hole 32 for the main pipe 1 to pass through. The axial side of one end of the main pipe 1 is provided with a convex ring 11 that can prevent the main pipe 1 from completely passing through the through hole 32. The bushing 2 includes a first end 21 that abuts between the inner end face of the threaded sleeve 3 and the end face of the convex ring 11, and a second end 22 that abuts between the inner ring of the through hole 32 and the side wall of the main pipe 1. The bushing 2 is made of soft and elastic material.

[0068] The convex ring 11 has a first chamfer 111 at one end near the through hole 32 to fit the shaft end face of the first end 21. The through hole 32 has a second chamfer 321 at the edge near the internal thread 31 to fit the other shaft end face of the first end 21. The through hole 32 is a tapered hole 322 in the direction away from the internal thread 31. The tapering degree of the first chamfer 111 is equal to the tapering degree of the second chamfer 321. The tapering degree of the second end 22 is equal to the tapering degree of the tapering hole 322. The end of the convex ring 11 away from the through hole 32 is provided with a third chamfer 112 whose tapering direction is opposite to that of the first chamfer 111.

[0069] As an optional implementation of the present invention, the main difference from Embodiment 1 lies in the choice of material for bushing 2. Both Embodiment 1 and Embodiment 2 use a relatively hard material, mainly for shock resistance. However, in some cases, bushing 2 needs to have sealing properties, such as in the transportation of gas media, or in applications involving the transportation of low-pressure media. In these cases, the requirements for shock resistance are lower, but the requirements for sealing are more stringent, such as in the transportation of natural gas.

[0070] Based on the existing sealing ring installed between the pipe joint 4 and the main pipe 1, we can also use the bushing 2 as a second layer of seal.

[0071] By adopting this implementation method, in some scenarios where seismic resistance requirements are not high, the soft elastic material forms an axial and radial interference fit between the main pipe 1 and the threaded sleeve 3, which has high sealing performance and greatly improves the sealing performance after the pipeline connection.

[0072] For soft and elastic materials, it can be common rubber, soft plastic, or soft metal as the middle layer and covered with rubber on the outer layer. This technical solution does not limit this.

[0073] Example 4: Please see Figure 1-7 The present invention also provides the following technical solution: a pipe connector, including the above-mentioned pipe connection structure, and further including a pipe joint 4, the pipe joint 4 including at least one of an N-type connector and a valve, at least one end of the pipe joint 4 is provided with an external thread 41 that mates with the internal thread 31, and the inner diameter of the pipe joint 4 is smaller than the outer diameter of the convex ring 11.

[0074] As an optional implementation of the present invention, based on any of embodiments 1-3, by defining the pipe joint 4, it is ensured that a pipe connection with high seismic performance can be formed after being connected with the threaded sleeve 3.

[0075] The working principle and usage process of this invention: During the tightening process, since the end of the pipe connector 4 is connected to the inside of the open end of the screw sleeve 3, the end face of the pipe connector 4 can abut against the end face of the convex ring 11 or the main pipe 1. This will cause the main pipe 1 to be pushed, which will put pressure on the bushing 2.

[0076] As bushing 2 moves with main pipe 1, the second end 22 of bushing 2 first enters through hole 32, filling the space between main pipe 1 and the inner ring of through hole 32. Subsequently, main pipe 1 drives bushing 2 to continue moving, and finally the second end 22 of bushing 2 is clamped between the end face of convex ring 11 and the inner end face of threaded sleeve 3, filling the space between the end faces of convex ring 11 and threaded sleeve 3. Finally, when threaded sleeve 3 is fully tightened, the end face of pipe fitting 4 has a continuous clamping force on the end of main pipe 1 or the end of convex ring 11.

[0077] When transporting high-pressure media, the pipeline experiences prolonged vibration, causing the main pipe 1 to vibrate, which in turn causes the threaded sleeve 3 to vibrate. The metal bushing 2, with its high strength, shear resistance, and tensile strength, significantly reduces the relative vibration between the threaded sleeve 3 and the main pipe 1, and is less prone to material deformation. Even if material deformation does occur, bushing 2 can be directly replaced.

[0078] Experimental Example 1: The existing unlined pipe connection structure was used as the control group, and the pipe connection structure in Example 1 was used as the experimental group. The main pipe 1 had the same dimensions, with an outer diameter of 20 mm, a diameter of 14.65 mm, and a length of 100 mm. The convex rings 11 all had an outer diameter of 28 mm and a length of 1.5 mm. The bushing 2 had a length of 24 mm.

[0079] Static stress analysis was performed on the experimental group and the control group respectively, and the simulation results were as follows: Figure 9-13 The analysis results.

[0080] from Figure 9-13 It can be seen that the pipe connection structure using bushing 2 has significantly improved strength and better resistance to deformation.

[0081] Experimental Example 2: The existing bushingless pipe connection structure was used as control group 1-2, and the pipe connection structure in Example 1 was used as experimental group 1-3. The results were compared as follows: Figure 14 The pipe is installed as shown, with one end of the pipe connection structure mounted on a three-dimensional bent pipe and the other end connected to a flexible hose. Both are pulsed at a pressure of 40MPa and a frequency of 1HZ to simulate extreme vibration conditions in real-world conditions.

[0082] In the experimental group and the control group, except for bushing 2, all other dimensions, materials and specifications are the same. Both the control group and the experimental group use 316L stainless steel, and bushing 2 is made of 316L stainless steel.

[0083] After the control group and experimental group underwent continuous experimentation, the experimental lifespan was recorded, and the following experimental results were obtained: Table 1: Lifespan Status

[0084] Conclusion: As shown in Table 1, the control group without bushings deformed after 200,000 vibrations and became unusable after 400,000 vibrations; while the control group with bushings could still be used normally after 1,000,000 vibrations.

[0085] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pipe connection structure, comprising a main pipe, a bushing fitted onto the main pipe, and a threaded sleeve for attaching the main pipe to a pipe fitting, wherein the inner wall of one end of the threaded sleeve is provided with an internal thread, and the end face of the other end of the threaded sleeve is provided with a through hole for the main pipe to pass through, wherein: The shaft side of one end of the main pipe is provided with a convex ring that can prevent the main pipe from completely passing through the through hole; the bushing includes: The first end can abut between the inner end face of the threaded sleeve and the end face of the convex ring; The second end can abut between the inner ring of the through hole and the side wall of the main shaft.

2. The pipe connection structure according to claim 1, wherein, The convex ring has a first chamfer at one end near the through hole to fit the shaft end face of the first end, and the through hole has a second chamfer on the edge near the internal thread to fit the other shaft end face of the first end. The taper of the first chamfer is less than or equal to the taper of the second chamfer.

3. The pipe connection structure according to claim 2, wherein, The through hole is a tapered hole that moves away from the direction of the internal thread, and the tapering degree of the second end is less than or equal to the tapering degree of the tapering hole.

4. The pipe connection structure according to claim 3, wherein, The taper of the first chamfer is equal to the taper of the second chamfer, and the taper of the second end is equal to the taper of the tapered hole.

5. The pipe connection structure according to claim 3, wherein, The end of the convex ring away from the through hole is provided with a third chamfer with a tapering direction opposite to that of the first chamfer, and the tapering degree of the third chamfer is less than that of the first chamfer.

6. The pipe connection structure according to claim 5, wherein, The third chamfer has a bulge in the middle of its tapered surface.

7. The pipe connection structure according to claim 6, wherein, The outer diameter of the convex ring is greater than the maximum diameter of the third chamfer.

8. The pipe connection structure according to claim 3, wherein, The outer edge of the end face of the convex ring near the through hole is also provided with a fourth chamfer, and the taper of the fourth chamfer is greater than that of the first chamfer.

9. The pipe connection structure according to claim 1, wherein, The bushing has an opening that extends through the first end and the second end, allowing the bushing to be unfolded into a sheet-like structure.

10. A pipe connector, comprising the pipe connection structure according to any one of claims 1-9, further comprising a pipe fitting, wherein, The pipe fitting includes at least one of an N-type connector and a valve, and at least one end of the pipe fitting is provided with an external thread that mates with the internal thread. The inner diameter of the pipe fitting is smaller than the outer diameter of the convex ring.

Images