A new type of support joint, double-wall gap catheter connecting structure and connecting process

Abstract

The present application relates to the technical field of double-wall gap conduit connection forming, in particular to a novel support joint, a double-wall gap conduit connection structure and a connection process. The novel support joint comprises a joint body, a boss part, an extension part and a through hole. The joint body is a cylindrical structure. A circle of boss parts is arranged on the outer wall of the joint body in the circumferential direction. The inner wall of the joint body extends outward in the circumferential direction to form the extension part. A plurality of through holes are arranged on the joint body in the axial direction. The purpose of the novel support joint, the double-wall gap conduit connection structure and the connection process is to solve the problems of high risk of leakage and high cost caused by too many welding processes in the connection process of the existing double-wall gap conduit connection structure.

Description

Technical Field

[0001] This invention relates to the field of double-wall gap conduit connection forming technology, specifically to a novel support joint, double-wall gap conduit connection structure and connection process. Background Technology

[0002] Currently, flexible connecting conduit assemblies are widely used in fuel system pipelines of civil and military aircraft, possessing certain pressure resistance and sealing performance. However, the reliability of single-layer flexible connecting conduits in certain special parts of aircraft has limitations. When subjected to complex alternating loads such as liquid pressure shocks, internal temperature shocks, external temperature shocks, and vibrations, single-layer flexible connecting conduits are prone to leaks at welds, mechanical connection seals, and bends. Furthermore, single-layer fuel pipeline systems are susceptible to thermal fatigue damage from impacts, collisions, or crossing fire zones, leading to conduit failure, fuel loss, and potentially aircraft combustion and explosion, endangering aircraft safety. Double-walled gap conduits are an advanced structure in modern aircraft and engine piping systems, primarily composed of double-walled gap tubes and double-layer connectors. They provide dual protection for the fuel pipeline system, offering effective leak detection and fuel drainage measures, and are essential piping components for meeting relevant standards and airworthiness requirements in current advanced aircraft.

[0003] Double-walled gap conduits mainly consist of double-walled gap tubes and double-layer connectors. Because both the inner and outer tubes must ensure sealing, double-walled conduits have extremely high requirements for the dimensional and positional tolerances of both the double-walled gap tubes and the connecting joints. The coaxiality and axial distance accuracy of the joint end faces after connection are key technical indicators for reducing assembly stress and ensuring that both the inner and outer connectors simultaneously fulfill their compensatory functions. High dimensional and positional accuracy of the inner and outer connectors after connection reduces the possibility of fatigue fracture and failure, and improves the sealing performance and service life of the flexible joint.

[0004] Simultaneously, the internal structure of the double-walled gap conduit should be designed with an electrical connection path, possessing certain voltage and current withstand limits. This ensures that after being subjected to lightning excitation during flight, the current between the inner and outer tubes can be successfully transmitted without damage, degradation, disruption, or interference. Therefore, it is necessary to design a reasonable support structure between the inner and outer tubes and optimize the connection process to guarantee the electrical connection function of the inner and outer tubes, thus ensuring the safety of the double-walled gap conduit during flight.

[0005] A search of domestic and international literature and patents revealed existing descriptions of the internal electrical lap joint structure and connection process for double-walled gap conduits. In the invention patent CN107511643A (Processing Method and Tooling for Double-Wall Stainless Steel Pipes for Commercial Large Passenger Aircraft), an electrical lap joint functional connector is proposed, with both the inner and outer connectors connected to the inner and outer pipes using welding. This welding process includes additional steps such as connector size measurement, cutting and adjustment, and end-face finishing to eliminate the accumulation of errors caused by heat shrinkage during multiple welding stages, ensuring the final dimensional tolerances of the double-walled gap conduit. This guarantees the coaxiality of the welded connector and the dimensional and positional tolerances of the inner and outer connectors. However, this welding process is lengthy, costly, and has a long delivery cycle, severely impacting the development and mass production of double-walled gap conduits.

[0006] Therefore, the inventors have provided a novel support joint, a double-walled gap conduit connection structure, and a connection process. Summary of the Invention

[0007] (1) Technical problems to be solved

[0008] This invention provides a novel support joint, a double-wall gap conduit connection structure, and a connection process, which solves the technical problems of high leakage risk and high cost caused by the numerous welding steps in the connection process of existing double-wall gap conduit connection structures.

[0009] (2) Technical solution

[0010] A first aspect of the present invention provides a novel support connector, comprising a connector body, a boss portion, an extension portion, and through holes. The connector body is a cylindrical structure. The boss portion is arranged circumferentially around the outer wall of the connector body. The extension portion is formed by extending the connector body circumferentially outward along the inner wall of the connector body. A plurality of through holes are provided through the connector body along its axial direction.

[0011] Furthermore, the plurality of through holes are evenly distributed circumferentially along the cross-section of the connector body.

[0012] Furthermore, the protrusion is annular.

[0013] Furthermore, the boss portion is located at the axial center of the connector body.

[0014] Furthermore, the extension is cylindrical.

[0015] A second aspect of the present invention provides a double-walled gap conduit connection structure, including an inner tube connector, an outer tube connector, and a novel support connector. The inner wall of the connector body and the inner wall of the extension are both attached to the outer wall of the inner tube. The outer wall of the connector body is respectively attached to the inner wall of the straight portion of the outer tube connector and the inner wall of the outer tube. The tube connector and the outer tube are respectively located on both sides of the boss portion. The inner tube connector is used to connect to the end of the inner tube.

[0016] Furthermore, the diameter of the boss portion is larger than the inner diameter of the outer tube.

[0017] Furthermore, the extension is located at one end of the connector body facing the inner tube connector.

[0018] Furthermore, the outer tube joint and the inner tube are connected by a rolling process.

[0019] A third aspect of the present invention provides a connection process for a double-walled gap conduit connection structure, comprising the following steps:

[0020] Based on the position and dimensions of the inner and outer pipe joints, the dimensions of the new support joint, the welding shrinkage, and the rolling extension, cut the dimensions of both ends of the inner and outer pipes.

[0021] The novel support joint is installed between the inner tube and the outer tube after the dimensions have been cut;

[0022] The inner tube connector is connected to the assembled inner tube by inner diameter rolling.

[0023] The novel support joint is fully welded to the inner tube using a fillet weld;

[0024] The outer pipe joint is fitted into the inner pipe joint after roll forming and the new support joint after fillet welding;

[0025] The novel support joint is then fully butt-welded to the outer pipe joint and the outer pipe.

[0026] (3) Beneficial effects

[0027] In summary, by using a novel support joint to connect the inner and outer pipes, this invention eliminates the need for welding fixtures, reduces weld seams, ensures the coaxiality of the inner and outer pipe joints after welding, and also guarantees a good electrical connection path between the inner and outer pipes. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a novel support joint provided in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a double-walled gap conduit connection structure provided in an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the assembly position of a novel support joint provided in an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the measurement and cutting of the inner and outer pipe dimensions before connecting the inner and outer pipe joints, provided by an embodiment of the present invention.

[0033] Figure 5 This is a schematic flowchart of the connection process of a double-walled gap conduit connection structure provided in an embodiment of the present invention.

[0034] In the picture:

[0035] 1-New type of support joint; 101-Joint body; 102-Boss part; 103-Extension part; 2-Inner tube joint; 3-Outer tube joint; 100-Inner tube; 200-Outer tube. Detailed Implementation

[0036] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. That is, the present invention is not limited to the described embodiments, and any modifications, substitutions and improvements to the parts, components and connection methods are covered without departing from the spirit of the present invention.

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "install" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] Figure 1 This is a schematic diagram of the structure of a novel support joint provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the novel support connector may include a connector body 101, a boss portion 102, an extension portion 103, and a through hole 104. The connector body 101 has a cylindrical structure. A boss portion 102 is provided around the outer wall of the connector body 101. The connector body 101 extends outward along the inner wall to form an extension portion 103. A plurality of through holes 104 are provided through the connector body 101 along its axial direction.

[0041] In the above embodiments, when the novel support joint 1 is used to connect the inner tube 100 and the outer tube 200, welding fixtures are not required, reducing weld seams and ensuring the coaxiality of the inner tube joint 2 and the outer tube joint 3 after welding. The opening of the through hole 104 also ensures good fluid flow in the gap between the inner tube 100 and the outer tube 200, ensuring that the outer tube 200 can work normally even if the inner tube 100 leaks or fails. The structure of the novel support joint 1 and the connection process with the inner tube 100 and the outer tube 200 can ensure an electrical connection path between the inner and outer tubes.

[0042] As an optional implementation method, such as Figure 1 As shown, multiple through holes 104 are uniformly distributed circumferentially along the cross-section of the connector body 101. Specifically, this arrangement of the through holes 104 ensures uniform fluid flow.

[0043] As an optional implementation method, such as Figure 1 As shown, the boss portion 102 is annular. The specific shape of the boss portion 102 is designed to fit and contact the outer tube connector 3 and the outer tube 200 perfectly, leaving no gaps at the connection between the outer tube connector 3 and the outer tube 200.

[0044] As an optional implementation method, such as Figure 1 As shown, the boss portion 102 is located at the middle position of the axial direction of the connector body 101. The boss portion 102 is designed in this position to have the same contact area with the outer pipe connector 3 and the outer pipe 200, so that the force is more evenly distributed during welding.

[0045] As an optional implementation method, such as Figure 1 As shown, the extension 103 is cylindrical. The specific shape of the extension 103 is designed to fit completely into contact with the inner tube 100, ensuring that there are no gaps at the connection with the inner tube 100 during welding.

[0046] Figure 2 This is a schematic diagram of a double-walled gap conduit connection structure provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the connection structure may include an inner tube connector 2, an outer tube connector 3, and a novel support connector 1. The inner wall of the connector body 101 and the inner wall of the extension 103 are both attached to the outer wall of the inner tube 100. The outer wall of the connector body 101 is attached to the inner wall of the straight part of the outer tube connector 3 and the inner wall of the outer tube 200, respectively. The outer tube connector 3 and the outer tube 200 are located on both sides of the boss part 102. The inner tube connector 2 is used to connect to the end of the inner tube 100.

[0047] In the above embodiments, the novel support joint 1 can ensure the coaxiality of the inner tube joint 2 and the outer tube joint 3 after connection, and ensure the synchronous axial and circumferential movement of the inner tube 100 and the outer tube 200 during use. At the same time, only one weld is needed to complete the welding between the novel support joint 1, the outer tube joint 3 and the outer tube 200. Compared with the existing two welds (the weld between the traditional support joint and the outer tube joint 3, and the weld between the traditional support joint and the outer tube 200), the welding process is simpler.

[0048] As an optional implementation method, such as Figure 1 As shown, the diameter of the boss portion 102 is larger than the inner diameter of the outer tube 200. Specifically, the exact diameter of the boss portion 102 is not limited and can be designed appropriately according to actual needs.

[0049] As an optional implementation method, such as Figure 2 As shown, the extension 103 is located at the end of the connector body 101 facing the inner tube connector 2. The extension 103 is positioned to facilitate better welding of the new support connector 1 to the inner tube 100.

[0050] As an optional implementation method, such as Figure 2-3As shown, the inner tube connector 2 and the inner tube 100 are connected by a rolling process. The rolling connection process between the inner tube connector 2 and the inner tube 100 can meet the requirements of lightweight and standardized processing and manufacturing of aircraft piping components, reduce one weld seam, and reduce the quality risk in pipe end processing. Compared with traditional welding methods, it has the advantages of low cost, high production efficiency, easy operation, reliable connection, and convenient maintenance.

[0051] Figure 5 This is a schematic flowchart of the connection process of a double-walled gap conduit connection structure provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the process may include the following steps:

[0052] S100. Based on the position and dimensions of the inner tube joint 2 and the outer tube joint 3, the dimensions of the new support joint 1, the welding shrinkage and the rolling extension, cut the dimensions of both ends of the inner tube 100 and the outer tube 200.

[0053] S200, Install the new support joint 1 between the inner tube 100 and the outer tube 200 after the dimensions have been cut;

[0054] S300. Connect the inner tube connector 2 to the assembled inner tube 100 by inner diameter rolling.

[0055] S400, The new support joint 1 is fully welded to the inner tube 100 by fillet welding;

[0056] S500, insert the outer pipe joint 3 into the inner pipe joint 2 after rolling connection, and the new support joint 1 after fillet welding;

[0057] S600, the new support joint 1 is fully welded to the outer pipe joint 3 and the outer pipe 200 by butt welding.

[0058] In the above embodiments, this connection process can reduce welding and intermediate cutting and measurement steps, shorten the manufacturing cycle, and reduce costs. The specific steps are as follows:

[0059] Step 1. Based on the positional dimensions (L) of the inner and outer pipe joints of the double-walled gap conduit, design the dimensions of a new type of support joint connecting the inner and outer pipes. The material of this joint is the same as that of the inner and outer pipes and the outer pipe sleeve. The height and width of the boss in the joint need to be designed according to the outer diameter and wall thickness of the outer pipe and the welding process. The thickness and length of the structure that is welded to the outer surface of the inner pipe also need to be designed according to the gap between the inner and outer pipes. The hole for the flow of liquid in the middle can also be designed into different shapes as needed.

[0060] Step 2. Based on the required dimensions (L) of the inner and outer tube connectors, the dimensions of the inner and outer tube support joints, welding shrinkage, and roll extension of the double-walled gap conduit, cut the dimensions of both ends of the inner and outer tubes, ensuring the dimensional accuracy of distances L0 and L1 to meet the final dimensional requirements of the double-walled gap conduit. Figure 4 As shown;

[0061] Step 3. Perform pre-welding surface treatment on the inner tube, outer tube, outer tube joint, inner tube joint, and new support joint. The inner tube joint has a groove structure inside, and the structure and number of grooves need to be designed according to the inner tube joint.

[0062] Step 4. Install the new support joint between the inner and outer tubes after they have been cut to the required dimensions, such as... Figure 3 As shown, the orientation of the new support joint should ensure that the structure welded to the inner tube is located outside the outer tube, and that the new support joint and the outer tube are in close contact after assembly.

[0063] Step 5. Place the inner tube connector and the assembled inner tube into the rolling connection equipment and clamping fixture for the inner diameter rolling process connection, so that the metal in the inner tube flows into the groove. Ensure that the metal filling amount inside the groove of the inner tube connector is sufficient. After filling, measure the inner diameter of the inner tube to verify whether the filling quality meets the requirements.

[0064] Step 6. Perform a full fillet weld between the new support joint and the inner tube. After welding, perform non-destructive testing on the welding quality. Then, assemble the flexible connection joint of the inner tube and perform an airtightness test on the inner tube and the inner tube joint to verify the reliability of the fillet weld quality and the rolling connection quality in Step 5.

[0065] Step 7. Insert the outer pipe fitting into the new support joint that has been rolled and welded to the inner pipe fitting, ensuring tight contact between the outer pipe fitting and the new support joint. Then, butt weld the outer pipe fitting, the new support joint, and the outer pipe together (e.g., ...). Figure 2 (As shown); after welding, non-destructive testing of the weld is performed, and the flexible connection joint of the outer tube is assembled to perform airtightness testing of the outer tube in order to verify the welding quality of the weld.

[0066] Step 8. Finally, measure the distance between the end faces of the outer pipe joint and the inner pipe joint to verify whether the joint shape and position dimension L meets the design requirements.

[0067] Example 1

[0068] A certain type of double-walled gap conduit component (the inner tube is a Ф50×1mm 5A02-O state aluminum alloy tube, and the outer tube is a Ф62×1mm 5A02-O state aluminum alloy tube) is designed with a minimum end face distance of 18±0.8mm between the inner tube and the outer tube.

[0069] After being connected using the support joint structure and connection process of the present invention, the inner and outer pipe channels of the double-walled gap conduit passed the airtight pressure test of 0.83MPa and pressure holding for 5 minutes. The end face distance was measured at four positions evenly along the circumferential direction of the inner and outer pipe sleeves, which was 17.92 to 18.35 mm, meeting the design requirements.

[0070] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0071] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A connection process for a double-walled gap conduit connection structure, the double-walled gap conduit connection structure comprising an inner tube connector (2), an outer tube connector (3), and a novel support connector (1), the novel support connector (1) comprising a connector body (101), a boss portion (102), an extension portion (103), and a through hole (104), the connector body (101) being a cylindrical structure, the connector body (101) having a ring of the boss portion (102) circumferentially arranged along its outer wall, and the connector body (101) extending outward along its inner wall circumferentially to form the extension portion (103). The connector body (101) has a plurality of through holes (104) extending through it along its axial direction; the inner wall of the connector body (101) and the inner wall of the extension (103) are both attached to the outer wall of the inner tube (100); the outer wall of the connector body (101) is respectively attached to the inner wall of the straight part of the outer tube connector (3) and the inner wall of the outer tube (200); the outer tube connector (3) and the outer tube (200) are respectively located on both sides of the boss (102); the inner tube connector (2) is used to connect to the end of the inner tube (100), characterized in that, The process includes the following steps: Based on the position and dimensions of the inner tube joint (2) and the outer tube joint (3), the dimensions of the new support joint (1), the welding shrinkage and the rolling extension, cut the dimensions of both ends of the inner tube (100) and the outer tube (200); The novel support joint (1) is installed between the inner tube (100) and the outer tube (200) after being cut to size; The inner tube connector (2) is connected to the assembled inner tube (100) by inner diameter rolling. The novel support joint (1) is fully welded to the inner tube (100) by a fillet weld; The outer pipe joint (3) is fitted into the inner pipe joint (2) after rolling connection and the new support joint (1) after fillet welding; The new type of support joint (1) is fully butt-welded to the outer pipe joint (3) and the outer pipe (200) to form a weld.

2. The connection process of the double-walled gap conduit connection structure according to claim 1, characterized in that, The diameter of the boss (102) is larger than the inner diameter of the outer tube (200).

3. The connection process of the double-walled gap conduit connection structure according to claim 1, characterized in that, The extension (103) is located at one end of the connector body (101) facing the inner tube connector (2).

4. The connection process of the double-walled gap conduit connection structure according to any one of claims 1-3, characterized in that, The outer tube joint (3) and the inner tube (100) are connected by a rolling process.

5. The connection process of the double-walled gap conduit connection structure according to claim 1, characterized in that, The plurality of through holes (104) are evenly distributed circumferentially along the cross-section of the connector body (101).

6. The connection process of the double-walled gap conduit connection structure according to claim 1, characterized in that, The protrusion (102) is annular.

7. The connection process of the double-walled gap conduit connection structure according to claim 6, characterized in that, The boss (102) is located at the middle position in the axial direction of the connector body (101).

8. The connection process of the double-walled gap conduit connection structure according to claim 1, characterized in that, The extension (103) is cylindrical.

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