Movable joint

Abstract

The invention relates to the technical field of pipeline movable joint manufacturing, and discloses a movable joint which comprises a first joint, a second joint, a third joint and a fourth joint. A spherical surface is arranged at the end of the second joint, and the spherical surface is used for being matched with the conical sealing surface to form sealing; the locking nut is used for connecting the first connector and the second connector, an internal thread is formed in the inner side wall of the locking nut, and the internal thread is matched with the external thread; the sealing ring is mounted between the first joint and the second joint; through the structural design of the first joint and the second joint, a formed sealing structure is provided with at least two sealing structures after being matched with a sealing ring, the sealing performance of the movable joint can be effectively improved, and even if the first two layers of sealing structures fail, the connection mode of the locking nut can also prevent the movable joint from generating overlarge leakage rate, so that the sealing performance of the movable joint is improved. The movable joint is particularly suitable for high-temperature medium pipelines, and the safety performance of the movable joint is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline flexible joints, in particular to a flexible joint. Background Art

[0002] Pipe union is a common pipe fitting, which is widely used in life and production. It is a pipe connector used for quick disassembly and installation of pipes. The conventional structure is mainly composed of three parts: nut, cloud head and flat joint. Each component is made of round steel or steel ingot forging and then machined. Its use makes the connection of pipes simpler, disassembly and replacement easier, and greatly saves the cost of pipe connection.

[0003] Due to the different process parameters such as temperature, pressure, medium, etc. of the pipeline, there are many structural forms of pipeline joints, such as socket joints, threaded joints, welded pipe type, ferrule type, flared type, etc. What they have in common is that the pipe joint at one end has a locking nut with a slip-on, which is screwed on the pipe joint with an external thread at the other end. The locking nut is rotated and the two joints are tightened. Then, with the help of the seals on the contact surfaces of the two joints, a sealing structure is formed to ensure that the medium in the pipe does not leak. Among them, thread anti-loosening is very critical. Under the influence of material creep, temperature change, load change, vibration and impact, the thread anti-loosening at the joint thread will drop to a critical value and the preload force will disappear, resulting in loose joints and reduced sealing performance, which is easy to cause leakage of fluid media. Summary of the invention

[0004] The purpose of the present invention is to provide a flexible joint for the conventional flexible joints in the related art, which has a simple sealing structure and is prone to leakage of fluid medium at the joints. The flexible joint can effectively improve the sealing performance of the pipeline connection on the basis of realizing quick installation and removal of the pipeline, making it difficult for the fluid medium to leak, thereby improving the safety performance of the pipeline connection.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A flexible joint comprises: a first joint, the outer wall of which is provided with an external thread, and the inner wall of which is provided with a conical sealing surface; a second joint, the end of which is provided with a spherical surface, the spherical surface is used to cooperate with the conical sealing surface to form a seal; a locking nut, used to connect the first joint and the second joint, the inner wall of the locking nut is provided with an internal thread, the internal thread is adapted to the external thread; a sealing ring, installed between the first joint and the second joint.

[0007] The flexible joint of the present invention has a sealing structure formed by the structural design of the first joint and the second joint, and has at least two sealing structures after cooperating with the sealing ring, which can effectively improve the sealing performance of the flexible joint. Even if the first two layers of sealing structures fail, the connection form of the locking nut can avoid excessive leakage of the flexible joint. It is particularly suitable for pipelines of high-temperature media and effectively improves the safety performance of the flexible joint.

[0008] In some optional embodiments, a spark plug is further included for monitoring medium leakage, and the spark plug is installed on the locking nut.

[0009] In some optional embodiments, the locking nut is provided with a monitoring hole penetrating through the side wall, and above the monitoring hole, a spark plug connector is fixed to the locking nut, and the spark plug connector is used to install the spark plug.

[0010] In some optional embodiments, the first joint is provided with a first notch, the first notch is L-shaped, and the sealing ring is installed in the first notch.

[0011] In some optional embodiments, a second notch is formed on an outer edge of the end surface of the second joint, and the second notch is L-shaped, and the second notch is used to accommodate the end surface of the first joint.

[0012] In some optional embodiments, the sealing ring is a metal C-shaped sealing ring.

[0013] In some optional embodiments, the outer side wall of the first joint is further provided with edges and corners, and the edges and corners are used for the installation tool to clamp and twist the first joint.

[0014] In some optional embodiments, there are at least two levels of difference in Brinell hardness between the locking nut and the first joint.

[0015] In some optional embodiments, a stopper is provided on the end face of the locking nut, and a baffle is provided on the second joint, wherein the baffle is used to abut against the stopper so that the locking nut and the second joint form a sleeve connection.

[0016] In some optional embodiments, the locking nut and the second joint are integrally formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a stereogram of the movable joint described in the embodiment;

[0019] Figure 2 is a half-section view of the movable joint described in the embodiment;

[0020] Figure 3 is an exploded schematic diagram of the flexible joint described in the embodiment;

[0021] Figure 4 is a schematic structural diagram of the first joint of the embodiment;

[0022] Figure 5 is a schematic structural diagram of the second joint in the embodiment;

[0023] Figure 6 is a schematic structural diagram of the locking nut described in the embodiment;

[0024] Markings in the figure: 100-flexible joint, 110-first joint, 111-external thread, 112-conical sealing surface, 113-first notch, 114-edge, 120-second joint, 121-spherical surface, 122-second notch, 123-baffle, 130-locking nut, 131-internal thread, 132-block, 133-monitoring hole, 134-edge, 140-sealing ring, 150-spark plug, 160-spark plug joint, 170-spark plug sealing gasket. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the field of nuclear engineering, the country is vigorously promoting experimental research on high-temperature liquid metal materials and engineering applications. A large number of tests and calibrations are required for various equipment and instruments suitable for liquid metal loops. This leads to frequent installation and disassembly of equipment, valves, instruments, etc. on the loop pipelines, and therefore pipeline joints are often used to achieve installation and disassembly of pipelines.

[0027] However, the commonly used pipe joints in the domestic market cannot meet the high temperature and strict sealing requirements of high-temperature liquid metal pipelines, especially liquid sodium, sodium-potassium alloy and other liquid metal medium pipelines, the working temperature is quite high (above 500°C), the sealing requirements are quite stringent, and a small medium leakage will cause a fire or explosion, thereby threatening people's lives and production safety. At present, the American Swagelok VCR joint can be applied to high-temperature liquid metal pipelines, but is limited to pipes below DN20mm in diameter. Therefore, in the high-temperature liquid metal circuit, the present application designs a pipe joint that can be used for large-diameter pipelines and can monitor medium leakage.

[0028] The present application is described below with reference to the accompanying drawings and specific embodiments:

[0029] Example

[0030] like Figure 1-Figure 6 As shown, a flexible joint 100 of the present invention includes: a first joint 110, an outer wall of which is provided with an external thread 111, and an inner wall of which is provided with a conical sealing surface 112; a second joint 120, an end of which is provided with a spherical surface 121, and the spherical surface 121 is used to cooperate with the conical sealing surface 112 to form a seal; a locking nut 130, used to connect the first joint 110 and the second joint 120, the inner wall of the locking nut 130 is provided with an internal thread 131, and the internal thread 131 is adapted to the external thread 111; a sealing ring 140, installed between the first joint 110 and the second joint 120.

[0031] Under the constraint of the locking nut 130, the spherical surface 121 of the second joint 120 can be pressed against the conical sealing surface 112 of the first joint 110, and a linear seal can be formed as the first layer sealing structure of the flexible joint 100. The sealing ring 140 is located between the first joint 110 and the second joint 120, and a second layer sealing structure can be formed. The locking nut 130 is located at the outermost layer of the flexible joint 100, and a third layer sealing structure can be formed by threading the first joint 110 and the second joint 120. Alternatively, the threaded connection of the locking nut 130 does not have sealing performance, but it can also prevent the flexible joint 100 from leaking too much.

[0032] The flexible joint 100 of the present invention has a sealing structure formed by the structural design of the first joint 110 and the second joint 120, and has at least two sealing structures after cooperating with the sealing ring 140, which can effectively improve the sealing performance of the flexible joint 100. Even if the first two layers of sealing structures fail, the connection form of the locking nut 130 can also prevent the flexible joint 100 from leaking too much. It is particularly suitable for pipelines of high-temperature media, and effectively improves the safety performance of the flexible joint 100.

[0033] In some optional implementations, a spark plug 150 is further included to monitor medium leakage, and the spark plug 150 is installed on the locking nut 130 .

[0034] Spark plug 150 is an important component of the gasoline engine ignition system. It is creatively used on the flexible joint 100 to monitor medium leakage. When the flexible joint 100 is used in a high-temperature pipeline, such as a high-temperature liquid metal pipeline loop, the structural characteristics of spark plug 150 can play a good monitoring role in the leakage of high-temperature medium at the flexible joint 100. When leakage occurs, the high-temperature medium enters the spark plug 150, and the spark plug 150 can cause a current response accordingly, thereby causing the circuit external to the spark plug 150 to sound an alarm.

[0035] In some optional embodiments, the locking nut 130 is provided with a monitoring hole 133 penetrating the side wall. Above the monitoring hole 133 , the locking nut 130 is fixed with a spark plug connector 160 , and the spark plug connector 160 is used to install the spark plug 150 .

[0036] The monitoring hole 133 serves as a reserved channel for monitoring the leakage of the medium, and can provide timely feedback on the actual situation of the medium leakage at the flexible joint 100. When the first two layers of sealing structures fail and there is a great risk of leakage by relying solely on the threaded seal, the high-temperature medium can enter the spark plug 150 through the monitoring hole 133, thereby issuing a leakage alarm in time. In addition, through the cooperation between the monitoring hole 133 and the spark plug joint 160, the spark plug 150 can be installed simply and quickly, thereby realizing the monitoring function of the spark plug 150.

[0037] In some optional embodiments, the first joint 110 is provided with a first notch 113 , the first notch 113 is L-shaped, and the sealing ring 140 is installed in the first notch 113 .

[0038] The first notch 113 facilitates the preliminary positioning of the sealing ring 140 during installation. Compared with the sealing ring 140 being directly clamped on the end face of the first joint 110, the design of the first notch 113 simplifies the fixing operation of the sealing ring 140, facilitates the disassembly and assembly of the flexible joint 100, and also avoids unnecessary displacement of the sealing ring 140 during use, such as displacement perpendicular to the axial direction of the pipeline. The sealing ring 140 can be limited to a certain extent to improve the sealing performance. Compared with the U-shaped notch, the L-shaped notch is easier to process, avoids the formation of weak side walls, and has better structural strength.

[0039] In some optional embodiments, the second joint 120 is provided with a second notch 122 at the outer edge of the end surface, and the second notch 122 is L-shaped. The second notch 122 is used to accommodate the end surface of the first joint 110 .

[0040] The L-shaped second notch 122 is used to accommodate the end face of the first joint 110, so that before the first joint 110 and the second joint 120 form a good conical seal, the end face of the first joint 110 can be effectively avoided from abutting against the second joint 120. At the same time, a certain limiting effect can be designed to prevent the spherical surface 121 of the second joint 120 from being too tight against the conical surface of the first joint 110, thereby avoiding deformation of the first joint 110, improving the installation performance of the flexible joint 100, and compared with the U-shaped notch, it is easy to process, avoids the formation of weak side walls, and has better structural strength.

[0041] In some optional embodiments, the sealing ring 140 is a metal C-shaped sealing ring.

[0042] The metal C-type sealing ring has excellent sealing performance. After selecting the appropriate material, it can meet the requirements of high temperature, high vacuum, ultra-low temperature and large temperature difference working conditions, and is particularly suitable for the flexible joint 100 of the high temperature pipeline.

[0043] In some optional embodiments, the outer side wall of the first joint 110 is further provided with an edge 114 , and the edge 114 is used for the installation tool to clamp and twist the first joint 110 .

[0044] The designed surface of the corner 114 can be used to fix or twist the first joint 110, so as to facilitate manual operation, so that the first joint 110 and the locking nut 130 form a stable threaded connection.

[0045] In some optional embodiments, there is at least two levels of difference in Brinell hardness between the locking nut 130 and the first joint 110 .

[0046] The Brinell hardness of the locking nut 130 and the first joint 110 are different and differ by at least two levels, thereby effectively avoiding the situation where the threads are stuck and ensuring the disassembly performance of the flexible joint 100.

[0047] In some optional embodiments, a stopper 132 is provided on the end face of the locking nut 130 , and a baffle 123 is provided on the second joint 120 . The baffle 123 is used to abut against the stopper 132 so that the locking nut 130 and the second joint 120 form a sleeve connection.

[0048] The split design of the locking nut 130 and the second joint 120 can effectively improve the flexibility of the connection operation and reduce the difficulty of installing and disassembling the pipe joint. The locking nut 130 can be sleeved on the outer side of the second joint 120, and the pipe connection can be completed without twisting the pipe. Compared with the threaded connection, the mutual abutment of the block 132 and the baffle 123 is used as a constraint for the sleeve connection, which not only makes the connection operation simpler, but also forms a multi-sided sealing structure, which enhances the sealing performance between the locking nut 130 and the second joint 120.

[0049] In some optional embodiments, the locking nut 130 and the second joint 120 are integrally formed.

[0050] The integrated design of the locking nut 130 and the second joint 120 can avoid a connection gap between the locking nut 130 and the second joint 120 , thereby effectively improving the sealing performance of the pipeline connection.

[0051] Based on the convenience of production and processing and the needs of specific working conditions, certain selections and combinations are made among various optional implementation methods, such as Figure 1-Figure 3 As shown, the flexible joint 100 includes a first joint 110 , a second joint 120 , a locking nut 130 , a sealing ring 140 , a spark plug 150 , a spark plug joint 160 and other components.

[0052] like Figure 4 As shown, the first joint 110 can be made of S30408 ​​stainless steel round bar, one end of which is connected to the pipeline or directly serves as the main body of the pipeline, which is called the pipeline end; the other end is called the connecting end, which is used to connect the second joint 120 and the locking nut 130, and the inner wall of the connecting end is processed with a conical sealing surface 112 through non-standard processing, and the inner side of the end face of the connecting end is provided with an L-shaped first notch 113, and the outer wall of the connecting end is provided with an external thread 111, which extends to the end face of the connecting end, and the outer wall of the connecting end is also provided with an edge 114, and the number of the edges 114 is not limited. For example, an edge surface 134 of six edges 114 can be formed, and the edges 114 are arranged close to the external thread 111.

[0053] like Figure 5 As shown, the second joint 120 can also be made of S30408 ​​stainless steel round rod, one end of which is connected to the pipeline or directly serves as the main body of the pipeline, which is called the pipeline end; the other end is called the connecting end, which is used to connect the first joint 110, and the outer wall of the connecting end is processed by non-standard processing to form a spherical surface 121 that matches the conical surface, and the spherical surface 121 extends to the end face of the connecting end, and the outer wall of the connecting end is also provided with an L-shaped second notch 122, and the second notch 122 is arranged close to the spherical surface 121. The side wall of the first notch 113 and the side wall of the second notch 122 can fit and align with each other when the first joint 110 and the second joint 120 are installed and connected, and a baffle 123 is also processed on the outer wall of the connecting end, and the baffle 123 protrudes from the side of the second joint 120 at the pipeline end.

[0054] like Figure 6As shown, the locking nut 130 can be selected from high alloy steel standard parts, and the material hardness is distinguished from the first joint 110 to avoid the situation where the inner and outer male and female threads are "bite-jammed". The Brinell hardness (HB) of the locking nut 130 material can be further set to be above level 2 of the Brinell hardness of the first joint 110 material. The end of the locking nut 130 connected to the first joint 110 has an internal thread 131 on its inner side wall, and the end of the locking nut 130 connected to the second joint 120 has a stopper 132 on its inner side wall. When the locking nut 130 is sleeved on the outer side of the second joint 120, The block 132 can abut against the baffle 123, and the inner diameter of the block 132 can be further designed to be equivalent to the outer diameter of the pipe end of the second joint 120. The inner diameter of the main body of the end of the locking nut 130 connected to the second joint 120 is equivalent to the outer diameter of the baffle 123. On the outer wall of the locking nut 130, there is a corresponding processed edge surface 134, such as the hexagonal edge surface 134 in the figure. On one of the edge surfaces 134, a monitoring hole 133 is opened that passes through the side wall of the locking nut 130. The monitoring hole 133 can be a circular hole with a diameter of 4 mm. The monitoring hole 133 also corresponds to the internal thread 131 area of ​​the locking nut 130.

[0055] like Figure 1-Figure 3 As shown, above the monitoring hole 133, the locking nut 130 is further welded with a spark plug connector 160, which can completely cover the monitoring hole 133. At the same time, the monitoring hole 133 is interconnected with the internal channel of the spark plug 150, and the spark plug connector 160 is correspondingly installed with the spark plug 150. The spark plug 150 can be a titanium alloy or nickel alloy spark plug 150 commonly used in automobiles, motorcycles, etc., and the sealing performance of the spark plug 150 installation is guaranteed by the added spark plug sealing gasket 170, that is, the spark plug 150 is used in conjunction with the spark plug sealing gasket 170 and the spark plug connector 160, and the spark plug connector 160 and the spark plug sealing gasket 170 are selected according to the fine thread specifications of the lower part of the spark plug 150. The spark plug 150 can be externally connected to an alarm circuit, and then when the high-temperature medium leaks at the flexible joint 100, the alarm function can be realized;

[0056] The sealing ring 140 is clamped between the first joint 110 and the second joint 120. The sealing ring 140 can be a metal C-shaped sealing ring. During installation, the sealing ring 140 can be initially placed in the first notch 113, or sleeved on the root of the spherical surface 121. After the locking nut 130 and the second joint 120 are sleeved with each other, as the connecting end of the first joint 110 is gradually screwed into the locking nut 130, the sealing ring 140 is gradually squeezed in the first notch 113 until a ring-shaped linear seal is formed, that is, a sealing structure formed by the annular deformation of the metal C-shaped seal. At the same time, the spherical surface 121 and the conical sealing surface 112 are pressed against each other, and a good linear seal can also be formed. At this time, the end face of the first joint 110 can be designed to abut against the bottom of the second notch 122, or a certain gap can be designed to be formed, and the gap corresponds to the monitoring hole 133, so that when both double seals fail, the leaked high-temperature medium can be detected by the spark plug 150 through the monitoring hole 133 at the first time.

[0057] The flexible joint 100 provided by the present invention has a simple structure, does not require special materials or processing technology, has a low cost, is easy to disassemble and assemble, has a high reuse rate, and is designed with a double sealing structure of a metal C-shaped sealing ring and a conical spherical sealing surface, which has a good effect in preventing leakage and greatly improves the reliability of use. At the same time, a leakage detection structure is designed to monitor the leakage of the medium during the operation of the flexible joint 100 in real time. Once the double sealing structure of the flexible joint 100 fails, the electrode lead connected to the wiring nut of the spark plug 150 will alarm at the first time to transmit the medium leakage signal, thereby improving the safety of use.

[0058] Through the selection of materials, the union 100 can also have high temperature resistance, and is particularly suitable for pipelines of high-temperature liquid metals, filling the product gap of large-diameter pipeline union 100 for transporting high-temperature liquid metals, such as pipelines with a diameter between DN20mm and DN100mm. It also has good application prospects in pipeline connections in similar working conditions such as nuclear energy and metallurgy.

[0059] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0060] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some optional implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

Claims

1. A flexible joint, characterized in that: include: A first joint (110) having an outer wall provided with an external thread (111) and an inner wall provided with a conical sealing surface (112); A second joint (120), the end of which is provided with a spherical surface (121), the spherical surface (121) being used to cooperate with the conical sealing surface (112) to form a seal; A locking nut (130) for connecting the first joint (110) and the second joint (120), wherein an inner wall of the locking nut (130) is provided with an internal thread (131), and the internal thread (131) is adapted to the external thread (111); A sealing ring (140) is installed between the first joint (110) and the second joint (120).

2. The flexible joint according to claim 1, characterized in that: It also includes a spark plug (150) for monitoring medium leakage, and the spark plug (150) is installed on the locking nut (130).

3. The flexible joint according to claim 2, characterized in that: The locking nut (130) is provided with a monitoring hole (133) penetrating the side wall. Above the monitoring hole (133), a spark plug connector (160) is fixed to the locking nut (130), and the spark plug connector (160) is used to install the spark plug (150).

4. The flexible joint according to claim 1, characterized in that: The first joint (110) is provided with a first notch (113), the first notch (113) is L-shaped, and the sealing ring (140) is installed in the first notch (113).

5. The flexible joint according to claim 1, characterized in that: The second joint (120) is provided with a second notch (122) at the outer edge of the end surface, the second notch (122) is L-shaped, and the second notch (122) is used to accommodate the end surface of the first joint (110).

6. The flexible joint according to claim 1, characterized in that: The sealing ring (140) is a metal C-shaped sealing ring.

7. The flexible joint according to claim 1, characterized in that: The outer side wall of the first joint (110) is also provided with an edge (114), and the edge (114) is used for an installation tool to clamp and twist the first joint (110).

8. The flexible joint according to claim 1, characterized in that: There are at least two levels of difference in Brinell hardness between the locking nut (130) and the first joint (110).

9. The flexible joint according to any one of claims 1 to 8, characterized in that: The end surface of the locking nut (130) is provided with a stopper (132), and the second joint (120) is provided with a stopper (123), and the stopper (123) is used to abut against the stopper (132) so that the locking nut (130) and the second joint (120) form a sleeve connection.

10. The flexible joint according to any one of claims 1 to 8, characterized in that: The locking nut (130) and the second joint (120) are integrally formed.

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