Method of making a catheter

Abstract

The present disclosure provides a manufacturing method of a conduit, belonging to the technical field of mechanical manufacturing. The manufacturing method of the conduit comprises the following steps: providing a transition pipe body and two main pipe bodies; cutting the transition pipe body into two half pipe bodies along the axial section of the transition pipe body, each of the two half pipe bodies having a cut surface; welding the two half pipe bodies on the side walls of the two main pipe bodies correspondingly, so that each of the two half pipe bodies is connected with a main pipe body, and the cut surface of the half pipe body is flush with the end surface of one end of the connected main pipe body, and the axis of the half pipe body is perpendicular to the axis of the connected main pipe body; coaxially connecting the two main pipe bodies, and abutting the cut surfaces of the two half pipe bodies to obtain the conduit, wherein the cut surfaces of the two half pipe bodies are coplanar with the connecting surfaces of the two main pipe bodies. The present disclosure can improve the machining precision.

Description

Technical Field

[0001] This disclosure belongs to the field of mechanical manufacturing technology, and specifically relates to a method for manufacturing a conduit. Background Technology

[0002] The split-type duct is a core component of the propeller. It securely assembles the impeller, motor rotor, and motor stator together and connects to both the front and rear ducts, serving a supporting function. The split-type duct includes a transition tube body and two main tube bodies. Each main tube body includes a first flange, a second flange, and an annular inner liner. The first and second flanges are coaxially connected to both ends of the inner liner. The two first flanges are coaxially connected to connect the two main tube bodies. The transition tube body includes a cylindrical body and a third flange. One end of the cylindrical body is connected to the outer peripheral wall of the inner liner of each of the two main tube bodies, and the other end is connected to the third flange. The axis of the cylindrical body is perpendicular to the axis of the inner liner, and the axial section of the transition tube body is coplanar with the connection surface of the two main tube bodies.

[0003] In related technologies, this split conduit is typically manufactured using casting and machining methods. After casting and demolding, the split conduit blank is ground and cut into two parts. Each part includes a main pipe and a half-pipe connected to the main pipe.

[0004] However, because split-type conduits are thin-walled structural components, they are difficult to cast and the casting process is hard to control, resulting in poor precision of the manufactured split-type conduits. Summary of the Invention

[0005] This disclosure provides a method for manufacturing a catheter, which can improve processing accuracy. The technical solution is as follows:

[0006] This disclosure provides a method for manufacturing a conduit suitable for an electric thruster. The method includes: providing a transition tube and two main tubes; dividing the transition tube into two half-tubes along its axial section, each half-tube having a cutting surface; welding the two half-tubes to the sidewalls of the two main tubes, such that each half-tube is connected to one main tube, and the cutting surface of the half-tube is flush with the end face of one end of the connected main tube, and the axis of the half-tube is perpendicular to the axis of the connected main tube; the two main tubes are coaxially connected, and the cutting surfaces of the two half-tubes are joined to obtain the conduit, wherein the cutting surfaces of the two half-tubes are coplanar with the connecting surfaces of the two main tubes.

[0007] In another implementation of this disclosure, the provision of two main bodies includes: processing a metal plate to obtain an annular inner liner; providing a support structure inside the inner liner, the outer wall of the support structure being fitted with the inner wall of the inner liner; and coaxially welding a first flange and a second flange to both ends of the inner liner to obtain the main body.

[0008] In another implementation of this disclosure, the support structure includes a plurality of arc-shaped members; the provision of the support structure inside the inner lining plate includes: arranging the plurality of arc-shaped members sequentially along the circumference of the inner lining plate, such that the plurality of arc-shaped members are connected end to end to form a ring.

[0009] In another implementation of this disclosure, the step of coaxially welding the first flange and the second flange to both ends of the inner liner plate includes: machining first V-shaped bevels at both ends of the inner liner plate; positioning and assembling the first flange and the second flange outside the inner liner plate such that the first flange and the second flange respectively cover the first V-shaped bevels at both ends of the inner liner plate; arranging a plurality of support ribs at intervals between the first flange and the second flange, the plurality of support ribs being arranged circumferentially around the first flange, and the length direction of each of the plurality of support ribs being the axial direction of the first flange, with both ends of each support rib respectively fitting against the first flange and the second flange; and welding the first flange and the second flange to both ends of the inner liner plate.

[0010] In another implementation of this disclosure, welding the first flange and the second flange to both ends of the inner liner plate includes: attaching tin foil to the inner wall of the inner liner plate, with the projection of the first V-groove along the radial direction of the inner liner plate onto the inner wall of the inner liner plate located on the tin foil; and welding at the first V-groove along the radial inward direction of the inner liner plate to weld the first flange and the second flange to both ends of the inner liner plate.

[0011] In another implementation of this disclosure, the step of welding the first flange and the second flange to both ends of the inner liner plate further includes: after welding the first flange and the second flange to both ends of the inner liner plate, milling the weld inside the inner liner plate to expose a metallic luster; performing a penetrant test on the exposed weld; and welding the weld inside the inner liner plate after the test is passed.

[0012] In another implementation of this disclosure, providing the transition tube body includes: processing a metal plate to obtain an annular cylinder; coaxially welding a third flange to one end of the cylinder, the other end of the cylinder being used to connect to the two main tube bodies.

[0013] In another implementation of this disclosure, welding the third flange to one end of the cylinder includes: providing a double V-groove on the cylinder or the third flange, wherein the larger opening of the double V-groove faces the inside of the cylinder, and the smaller opening of the double V-groove faces the outside of the cylinder; attaching tin foil to the outer wall of the cylinder, wherein the projection of the double V-groove along the radial direction of the cylinder onto the outer wall of the cylinder is located on the tin foil; and welding at the double V-groove in a radially outward direction along the cylinder to weld the third flange to one end of the cylinder.

[0014] In another implementation of this disclosure, the step of welding the two half-pipes to the sidewalls of the two main pipes includes: machining assembly notches on the inner lining plates of the two main pipes respectively, the assembly notches extending from one end of the main pipe to the middle of the main pipe; assembling the half-pipe into the corresponding assembly notch of the main pipe, with the cross-sectional surface of the half-pipe flush with the end face of one end of the corresponding main pipe, the assembly notch communicating with the interior of the corresponding half-pipe; and welding the half-pipe to the corresponding main pipe together.

[0015] In another implementation of this disclosure, welding the half-pipe to the corresponding main pipe includes: machining a second V-shaped bevel on the edge of the inner liner plate near the assembly notch; attaching tin foil to the inner wall of the inner liner plate, with the projection of the second V-shaped bevel along the radial direction of the inner liner plate onto the tin foil; and welding at the second V-shaped bevel along the radial inward direction of the inner liner plate to weld the inner liner plate to the corresponding half-pipe.

[0016] The beneficial effects of the technical solutions provided in this disclosure are:

[0017] When manufacturing the conduit using the method provided in this embodiment, the process first involves dividing the transition tube into two halves, welding each half to one of the two main tubes, and then coaxially connecting the two main tubes with their cut surfaces aligned. This allows a single conduit structure to be disassembled into multiple components. During manufacturing, each component can be individually processed according to the conduit's size, and then directly welded together to form the conduit. This avoids the need for integral casting and significantly improves the conduit's manufacturing precision. Furthermore, welding multiple components together reduces manufacturing costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the split catheter provided in the embodiments of this disclosure;

[0020] Figure 2 This is a flowchart of a method for manufacturing a catheter according to an embodiment of this disclosure;

[0021] Figure 3 This is a flowchart of another method for manufacturing a catheter provided in this disclosure embodiment;

[0022] Figure 4 This is a top view of the support structure provided in the embodiments of this disclosure;

[0023] Figure 5 This is an axial cross-sectional view of the support structure provided in the embodiment of this disclosure, which is disposed in the inner lining plate;

[0024] Figure 6 This is a schematic diagram showing the welding of the inner lining plate to the first flange and the second flange according to an embodiment of this disclosure;

[0025] Figure 7 This is a schematic diagram showing the arrangement of the supporting stiffeners outside the inner lining plate according to an embodiment of this disclosure;

[0026] Figure 8 This is a schematic diagram of the structure of the supporting stiffener provided in the embodiment of this disclosure;

[0027] Figure 9 This is a schematic diagram of the welding of the transition tube body provided in an embodiment of this disclosure;

[0028] Figure 10 This is a schematic diagram of the welding between the transition tube and the main tube provided in an embodiment of this disclosure.

[0029] The symbols in the diagram represent the following meanings:

[0030] 100. Main body; 101. First flange; 102. Second flange; 103. Inner liner plate; 1030. Assembly notch; 1031. First V-groove; 1032. Second V-groove; 104. Connecting stiffener plate;

[0031] 200. Transition pipe body; 201. Shell; 202. Third flange; 203. Double V bevel;

[0032] 300, Support structure; 301, Arc-shaped component; 3011, Arc-shaped piece; 3010, Gap; 302, First connector; 303, Second connector; 304, Support rib; 3041, Arc-shaped notch. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0034] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0035] Split ducts are a core component of propellers. Split ducts can fix and assemble the impeller, motor rotor, and motor stator together, and can be connected to the front and rear ducts to serve as a support.

[0036] Figure 1 This is a schematic diagram of the structure of the split catheter provided in the embodiments of this disclosure, as shown below. Figure 1 As shown, the split conduit includes a transition tube 200 and two main tubes 100, which are coaxially connected. The transition tube 200 is located on the same side of the two main tubes 100 and is connected to each of the two main tubes 100. The axis of the transition tube 200 is perpendicular to the axes of the two main tubes 100, and the axial section of the transition tube 200 is coplanar with the connection surface of the two main tubes 100.

[0037] Each main body 100 includes a first flange 101, a second flange 102, an inner liner 103, and multiple connecting stiffeners 104. The first flange 101 and the second flange 102 are coaxial and spaced apart. The inner liner 103 is located between the first flange 101 and the second flange 102, and is connected to both the first flange 101 and the second flange 102. Multiple connecting stiffeners 104 are evenly spaced along the circumference of the inner liner 103 on its outer wall, and both ends of each connecting stiffener 104 are connected to the first flange 101 and the second flange 102, respectively.

[0038] The two main pipe bodies 100 are detachably connected by fasteners such as bolts on their respective second flanges 102. One of the first flanges 101 of the two main pipe bodies 100 is connected to the front conduit, and the other first flange 101 is connected to the rear conduit.

[0039] The transition pipe body 200 has a cylindrical structure. The transition pipe body 200 includes a cylindrical body 201 and a third flange 202. One end of the cylindrical body 201 is connected to the inner lining plate 103 of the two main pipe bodies 100, and the other end of the cylindrical body 201 is coaxially connected to the third flange 202.

[0040] The split conduit provided in this embodiment is a thin-walled titanium alloy structure with external dimensions of 1238mm × 1384mm and a height of 456.5mm. The inner liner 103 has a wall thickness of 6mm. The first flange 101, the second flange 102, and the third flange 202 are all 8mm thick.

[0041] Figure 2 This is a flowchart of a method for manufacturing a catheter according to an embodiment of this disclosure, combined with... Figure 2 This manufacturing method is used to manufacture the aforementioned split catheter. The catheter manufacturing method includes:

[0042] S201: Provides a transition tube and two main tubes.

[0043] S202: The transition tube is divided into two halves along the axial section of the transition tube, and each half of the two halves has a cutting surface.

[0044] S203: Weld two half-pipes to the side walls of two main pipes, such that each half-pipe is connected to a main pipe, and the cross-section of the half-pipe is flush with the end face of one end of the connected main pipe, and the axis of the half-pipe is perpendicular to the axis of the connected main pipe.

[0045] S204: Two main tubes are coaxially connected, and the cut surfaces of the two half tubes are joined together to form a conduit, wherein the cut surfaces of the two half tubes are coplanar with the connecting surfaces of the two main tubes.

[0046] When manufacturing the conduit using the method provided in this embodiment, the process first involves dividing the transition tube into two halves, welding each half to one of the two main tubes, and then coaxially connecting the two main tubes with their cut surfaces aligned. This allows a single conduit structure to be disassembled into multiple components. During manufacturing, each component can be individually processed according to the conduit's size, and then directly welded together to form the conduit. This avoids the need for integral casting and significantly improves the conduit's manufacturing precision. Furthermore, welding multiple components together reduces manufacturing costs.

[0047] Figure 3 This is a flowchart of another method for fabricating a catheter provided in this disclosure embodiment, combined with... Figure 3 The methods for fabricating catheters include:

[0048] S301: Process the metal plate to obtain an annular inner lining plate.

[0049] In this embodiment, the inner lining plate is obtained by rolling a titanium alloy plate on a roll and then welding it to form a ring.

[0050] The inner lining plate has a wall thickness of 6mm.

[0051] S302: A support structure is installed inside the lining plate.

[0052] Multiple arc-shaped components are arranged sequentially along the circumference of the inner lining plate, so that the multiple arc-shaped components are connected end to end to form a ring.

[0053] Figure 4 This is a top view of the support structure provided in the embodiments of this disclosure, such as... Figure 4 As shown, a support structure 300 is spot-welded to the inside of the inner lining plate. The support structure 300 is used to support the inner lining plate.

[0054] For example, the support structure 300 includes a plurality of arc-shaped members 301, which are connected sequentially along the circumference of the inner liner to form a ring.

[0055] The support structure 300 is formed by multiple arc-shaped parts 301, which is not only convenient and quick, but also relatively flexible and easy to assemble and disassemble.

[0056] In this embodiment, there are three arc-shaped components 301. Correspondingly, the support structure 300 also includes a first connector 302. The first connector 302 is used to connect two of the three arc-shaped components 301 together to form an arc-shaped component group with a longer arc length. Two gaps 3010 are formed between the third arc-shaped component 301 and the arc-shaped component group. A wedge is inserted between each gap 3010 so that each arc-shaped component 301 can be tightly fitted to the inner wall of the inner arc plate.

[0057] In order to prevent the circle formed by the arc-shaped component 301 from deforming, a second connector 303 is arranged between the two arc-shaped components that form the gap. The second connector 303 is connected to the two arc-shaped components 301 that form the gap respectively.

[0058] The above-mentioned support structure, by setting multiple arc-shaped components 301, first connectors 302, and second connectors 303, not only facilitates the placement of the support structure 300 within the inner lining plate, but also allows for appropriate adjustment of the size of the circle formed by the arc-shaped components using wedges, ensuring that the circle formed by the arc-shaped components does not deform and can fit snugly against the inner lining plate. In other words, when spot-welding the support structure 300 to the inner wall of the inner lining plate 103, each arc-shaped component 301 can be first positioned inside the inner lining plate 103, ensuring that each arc-shaped component 301 fits snugly against the inner wall of the inner lining plate 103. Then, a portion of the arc-shaped components 301 are joined together using the first connectors 302. Next, wedges are inserted between the arc-shaped components connecting the other portion of the arc-shaped components 301 to the first connectors 302 to tightly fit each arc-shaped component against the inner wall of the inner lining plate. Finally, the two arc-shaped components with inserted wedges are connected together using the second connectors 303. Finally, spot weld each curved component to the inner lining plate.

[0059] In other examples, the number of arc-shaped components 301 can also be other numbers, such as four or five. If the number of arc-shaped components 301 is different, the number of gaps formed between the multiple arc-shaped components 301 can also be set according to the specific situation, such as three or four. Correspondingly, the number of second connecting components 303 is also three or four, etc. The number of first connecting components 302 is also modified accordingly.

[0060] Figure 5 This is an axial cross-sectional view of the support structure provided in the embodiment of this disclosure, which is disposed in the inner lining plate, as shown below. Figure 5As shown, in this embodiment, to improve the support effect and minimize deformation of the inner lining plate during welding, the minimum distance between each arc-shaped component 301 and the two end faces of the inner lining plate is 50mm (that is, the minimum distance d between the support structure and the welds at both ends of the inner lining plate is 50mm). To reduce the weight of the arc-shaped component 301, each arc-shaped component 301 includes two arc-shaped pieces 3011. The two arc-shaped pieces 3011 are spaced apart along the axial direction of the inner lining plate 103, and the minimum distance d between each arc-shaped piece 3011 and the end face of the inner lining plate is 50mm. Along the circumference of the arc-shaped component 301, adjacent arc-shaped pieces 3011 are connected together by a first connector 302 or a second connector 303.

[0061] In this embodiment, the first connector 302 is a block structure, and is welded to two arc-shaped components 301 that are mated together. The second connector 303 is at least one sheet structure, and is welded to two arc-shaped components 301 with wedges inserted into them.

[0062] S303: Weld the first flange and the second flange to both ends of the inner liner plate respectively to obtain the main body.

[0063] Optionally, step S303 is obtained in the following way:

[0064] 3031: The first V-shaped bevel is machined at both ends of the inner lining plate.

[0065] See Figure 6 By setting a first V-shaped groove 1031 on the outside of both ends of the inner liner plate, the outer opening of the weld formed by the inner liner plate 103 and the first flange 101 or the second flange 102 can be larger, which facilitates welding.

[0066] 3032: Position and assemble the first flange and the second flange outside the inner liner plate, such that the first flange and the second flange respectively cover the first V-shaped bevel at both ends of the inner liner plate.

[0067] Figure 6 This is a schematic diagram of the welding of the inner lining plate to the first flange and the second flange according to an embodiment of this disclosure. See also... Figure 6 With the inner liner plate supported by the support structure 300, the first flange 101 and the second flange 102 are positioned outside the inner liner plate 103, so that the first flange 101 and the second flange 102 cover the first V-shaped bevel 1031 at both ends of the inner liner plate 103.

[0068] 3033: Multiple support stiffeners are arranged at intervals between the first flange and the second flange.

[0069] Figure 7 This is a schematic diagram showing the arrangement of the supporting stiffeners outside the inner lining plate according to an embodiment of this disclosure. See also... Figure 7 In this embodiment, multiple support stiffeners 304 are arranged at intervals along the circumference of the first flange, and the length direction of each support stiffener is the axial direction of the first flange. The two ends of each support stiffener are respectively attached to the first flange and the second flange.

[0070] Before welding the first flange and the second flange to the inner liner, a ring of support stiffeners is arranged between the first flange and the second flange. The support stiffeners can support the first flange and the second flange and reduce their deformation.

[0071] Figure 8 This is a schematic diagram of the supporting stiffener provided in an embodiment of this disclosure. See also: Figure 8 In this embodiment, to facilitate the arrangement of the support stiffener between the first flange and the second flange, the two ends of the support stiffener 304 are provided with arc-shaped notches 3041. The two arc-shaped notches 3041 face the first flange 101 and the second flange 102, respectively.

[0072] In this embodiment, there are 12 supporting stiffeners 304. These 12 stiffeners 304 are divided into two groups: the first group has 3 stiffeners, and the second group has 9 stiffeners. The spacing between two adjacent stiffeners 304 in the first group is half the spacing between two adjacent stiffeners in the second group. The minimum spacing between the edge stiffeners in the first group and the edge stiffeners in the second group is equal to the spacing between two adjacent stiffeners in the second group. This allows the stiffeners in the first group to support the first and second flanges during welding of the liner plate to the transition pipe body, preventing deformation of the first and second flanges due to welding of the liner plate.

[0073] 3034: Weld the first flange and the second flange to both ends of the inner liner plate, respectively.

[0074] In this embodiment, when the first flange and the second flange are welded to both ends of the inner liner plate, they can be obtained in the following manner:

[0075] (1) Adhere aluminum foil to the inner wall of the inner lining panel (the location for attaching the aluminum foil can be found in [reference]). Figure 6 (at point a in the middle), and the projection of the first V-shaped bevel along the radial direction of the inner liner plate onto the inner wall of the inner liner plate is located on the tin foil.

[0076] Applying tin foil to the inner wall of the lining plate can prevent the root weld from being oxidized.

[0077] (3) Weld along the radial direction of the inner liner at the first V-groove, and weld the first flange and the second flange to the two ends of the inner liner respectively.

[0078] Welding from the outside in facilitates welding and also makes root cleaning easier (the root of the weld is machined before re-welding). Although the root of the weld is located inside the liner plate, the large inner diameter of the liner plate allows for access to clean the root of the weld.

[0079] 3035: Mill the weld seams inside the inner lining plate to expose the metallic luster of the weld seams.

[0080] Because split-type conduits have certain stress requirements, all welds must be fully penetrated during the welding process. This means that the back side of the weld (the root weld) needs to be machined before re-welding to ensure complete penetration.

[0081] 3036: Perform penetrant testing on welds that show metallic luster.

[0082] 3037: After passing inspection, weld the welds inside the inner lining plate.

[0083] After the front weld (the weld on the outside of the inner liner) is completed, the machine shop moves the machine to the reverse weld (the weld on the inside of the inner liner) to expose the titanium alloy weld. The weld is then inspected for metallic luster and passed 100% PT (Penetrant Testing) before the reverse weld is welded. This process ensures that double-sided welding of all welds is feasible and accessible, and also allows for root cleaning via machining, thus improving weld quality.

[0084] In this embodiment, the welding process is carried out by manual tungsten inert gas welding with DC positive polarity, shielding gas Ar≥99.99%, and layer temperature≤50℃. The specific process is shown in Table 1 below.

[0085] Table 1 Welding parameters for titanium alloys

[0086]

[0087] 3038: Multiple connecting stiffeners are welded outside the inner lining plate and between the first flange and the second flange.

[0088] In this embodiment, there are ten connecting stiffeners. Each connecting stiffener is located between two adjacent supporting stiffeners in the second group. The interval between the connecting stiffener and the adjacent supporting stiffener is equal to the interval between two adjacent supporting stiffeners in the first group. When the connecting stiffener is welded to the outside of the inner lining plate, the welding procedure is shown in Table 1.

[0089] S304: The metal plate is processed to obtain an annular cylinder.

[0090] In this embodiment, the metal plate is a titanium alloy plate.

[0091] Since the transition pipe body consists of a cylindrical body and a third flange, with one end of the cylindrical body connected to the third flange, in order to process the transition pipe body, it is necessary to first obtain the cylindrical body and then weld the third flange to one end of the cylindrical body.

[0092] S305: The third flange is coaxially welded to one end of the cylinder.

[0093] The other end of the cylinder is used to connect to the two main bodies.

[0094] Optionally, S305 includes:

[0095] 3051: A double V-groove is provided on the cylinder or the third flange, with the larger opening of the double V-groove facing the inside of the cylinder and the smaller opening of the double V-groove facing the outside of the cylinder.

[0096] Figure 9 This is a schematic diagram of the assembly and welding of the transition tube body provided in an embodiment of this disclosure. See also... Figure 9 Since the thickness of the cylinder 201 is relatively large, in order to achieve full penetration during the welding process, a double V-groove 203 is formed between the cylinder 201 and the third flange 202. This increases the length of the weld between the cylinder 201 and the third flange 202, thereby improving the weld strength between the cylinder 201 and the third flange 202.

[0097] 3052: Aluminum foil is pasted on the outer wall of the cylinder, and the projection of the double V-groove along the radial direction of the cylinder onto the inner wall of the cylinder is located on the aluminum foil.

[0098] Attach aluminum foil to the outer wall of the cylinder (the location for attaching the aluminum foil can be found in [reference]). Figure 9 (at point b) can be wrapped with tin foil to prevent the root weld between the cylinder and the third flange from being oxidized.

[0099] 3053: Weld the third flange to one end of the cylinder at the double V-groove along the radial outward direction of the cylinder.

[0100] Welding from the inside out allows the root weld between the cylinder and the third flange to be located outside the cylinder, facilitating subsequent root cleaning.

[0101] 3054: Mill the weld seams on the outside of the cylinder to expose the metallic luster.

[0102] 3054: Perform penetrant testing on welds that show metallic luster.

[0103] 3055: After passing the inspection, the welds on the outside of the cylinder are re-welded.

[0104] After the front weld (the internal weld between the cylinder and the third flange) is completed, the machine shop moves the machine to the back weld (the external weld between the cylinder and the third flange) to expose the titanium alloy weld. The weld should have a metallic luster and pass 100% PT flaw detection before the back weld is completed. This process ensures both the feasibility and accessibility of double-sided welding, while also allowing for root cleaning via machining, thus improving weld quality.

[0105] In this embodiment, the welding process is carried out by manual tungsten inert gas welding with DC positive polarity, shielding gas Ar≥99.99%, and layer temperature≤50℃. The specific process is shown in Table 1.

[0106] S306: Weld two half-pipes to the side walls of two main pipes, such that each half-pipe is connected to a main pipe, and the cut surface of the half-pipe is flush with the end face of one end of the connected main pipe.

[0107] Optionally, S306 includes:

[0108] 3061: Assembly notches are machined on the inner lining plates of the two main bodies respectively, and the assembly notches extend from the end of the inner lining plate connected to the second flange to the middle of the inner lining plate.

[0109] By providing assembly notches in the inner liner, it is easy to connect the half-pipe to the interior of the main pipe after connection.

[0110] 3062: The half-pipe is assembled into the assembly notch of the corresponding main pipe, and the cut surface of the half-pipe is flush with the end face of the first end of the corresponding main pipe, and the assembly notch is connected to the interior of the corresponding half-pipe.

[0111] Step 3062 can be obtained in the following way:

[0112] (1) A second V-shaped bevel 1032 is machined on the edge of the inner lining plate 103 near the assembly notch 1030.

[0113] Figure 10 This is a schematic diagram of the welding between the transition tube and the main tube according to an embodiment of this disclosure. See also: Figure 10 Along the radial direction of the inner liner 103, the second V-shaped bevel 1032 is located inside the inner liner 103 and on the structure of the inner liner 103 that forms the sidewall of the assembly notch 1030.

[0114] (2) Attach aluminum foil to the inner wall of the lining panel (the location for attaching the aluminum foil can be found in [reference]). Figure 10 (at point c in the middle), and the projection of the second V-shaped bevel along the radial direction of the inner liner plate onto the inner wall of the inner liner plate is located on the tin foil.

[0115] (3) Weld along the radial direction of the inner lining plate at the second V-groove to weld the inner lining plate to the corresponding half-pipe.

[0116] (4) Mill the external weld between the cylinder and the inner lining plate to expose the metal luster of the weld.

[0117] (5) Perform penetrant testing on welds that show metallic luster.

[0118] (6) After the inspection is passed, the external weld between the cylinder and the inner lining plate is welded.

[0119] In this embodiment, the above welding process is carried out by manual tungsten inert gas welding with DC positive polarity, shielding gas Ar≥99.99%, and layer temperature≤50℃. The specific process is as shown in Table 1 above.

[0120] S307: Vacuum annealing is performed on the main body and supporting structure together to relieve stress.

[0121] This can further reduce deformation.

[0122] After annealing, remove the tooling and check whether the machining dimensions of the split conduit and the inner liner wall thickness are within the required range.

[0123] S308: Perform flaw detection on all welds of the annealed welded parts.

[0124] After passing inspection, the welds were transferred to the non-destructive testing (PT) test. All welds underwent 100% PT (Penetrant Testing) and met the NB / T47013-2015 Class I qualification.

[0125] S309: Connect two main tubes coaxially and align the cut surfaces of two half tubes together to obtain a conduit, wherein the cut surfaces of the two half tubes are coplanar with the connecting surfaces of the two main tubes.

[0126] By fastening the two completed main tubes together with bolts or other fasteners, a split conduit can be formed.

[0127] In this embodiment, a reasonable and effective welding process is designed to split the conduit into two main bodies and a transition body. The two main bodies and the transition body are first welded together individually. After processing, each main body is welded to a half-pipe cut from the transition body to form the conduit. In other words, by first disassembling the conduit into components, both the operability and accessibility of double-sided welding of all weld seams are ensured, and the weld root can be cleaned by machining, improving weld quality. The two main bodies can also be fixed back-to-back by spot welding to reduce deformation. To reduce the shrinkage deformation of the outer diameter of the inner liner plate caused by welding the upper and lower circumferential seams, a 1mm welding shrinkage allowance is reserved on one side of the outer diameter of the inner liner plate to ensure the final wall thickness of the inner liner plate. Furthermore, a support structure for the inner liner plate is designed to ensure the inner diameter of the inner liner plate, bind the inner liner plate to prevent it from opening outwards during processing and cutting, and also serve as an assembly positioning structure for the transition body, meeting the post-weld dimensional requirements of the conduit. Moreover, the above manufacturing method also meets the specific welding requirements of titanium alloys. By cleaning the reverse weld seam through machining and welding after passing the colorimetric inspection, and by wrapping the weld seam with tin foil to prevent oxidation on the reverse side, the quality of weld seams between titanium alloy structural components is improved.

[0128] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for manufacturing a catheter, characterized in that, The conduit is suitable for electric thrusters, and the method for manufacturing the conduit includes: A transition tube and two main tubes are provided, each of which is obtained by: processing a metal plate to obtain an annular inner liner; providing a support structure inside the inner liner, the outer wall of the support structure being fitted with the inner wall of the inner liner; and coaxially welding a first flange and a second flange to both ends of the inner liner to obtain the main tube, wherein the two ends of the inner liner are respectively machined with a first V-shaped bevel. The transition tube is divided into two halves along its axial section, and each half has a cutting surface. Assembly notches are machined on the inner lining plates of the two main bodies respectively. The assembly notches extend from one end of the main body to the middle of the main body. The half-tube is assembled into the corresponding assembly notch of the main body, and the cross-section of the half-tube is flush with the end face of one end of the corresponding main body. The assembly notch communicates with the interior of the corresponding half-tube. The half-tube is welded to the corresponding main body, so that each half-tube is connected to a main body. The axis of the half-tube is perpendicular to the axis of the connected main body. The two main tubes are coaxially connected, and the cut surfaces of the two half tubes are joined together to obtain the conduit, wherein the cut surfaces of the two half tubes are coplanar with the connecting surfaces of the two main tubes. The step of welding the first flange and the second flange to both ends of the inner liner plate includes: Tin foil is pasted on the inner wall of the liner plate, and the projection of the first V-shaped bevel along the radial direction of the liner plate onto the inner wall of the liner plate is located on the tin foil; welding is performed at the first V-shaped bevel along the radial inward direction of the liner plate, and the first flange and the second flange are respectively welded to both ends of the liner plate.

2. The method for manufacturing the catheter according to claim 1, characterized in that, The support structure includes multiple arc-shaped components; The provision of a support structure inside the inner lining plate includes: The plurality of arc-shaped components are arranged sequentially along the circumference of the inner lining plate, so that the plurality of arc-shaped components are connected end to end to form a ring.

3. The method for manufacturing the catheter according to claim 1, characterized in that, The step of coaxially welding the first flange and the second flange to both ends of the inner liner plate includes: The first flange and the second flange are positioned and assembled outside the inner liner plate, such that the first flange and the second flange respectively cover the first V-shaped bevel at both ends of the inner liner plate; Multiple support ribs are arranged at intervals between the first flange and the second flange. The multiple support ribs are arranged at intervals along the circumference of the first flange, and the length direction of each support rib is the axial direction of the first flange. The two ends of each support rib are respectively attached to the first flange and the second flange. The first flange and the second flange are welded to both ends of the inner liner plate, respectively.

4. The method for manufacturing the catheter according to claim 1, characterized in that, The step of welding the first flange and the second flange to both ends of the inner liner plate respectively further includes: After welding the first flange and the second flange to both ends of the inner liner plate, the weld inside the inner liner plate is milled to expose a metallic luster. The welds exhibiting a metallic luster were subjected to penetrant testing. After passing the inspection, the welds inside the inner lining plate are welded.

5. The method for manufacturing the catheter according to any one of claims 1-4, characterized in that, The provision of the transition tube includes: The metal plate is processed to obtain an annular cylinder; The third flange is coaxially welded to one end of the cylinder, and the other end of the cylinder is used to connect to the two main bodies.

6. The method for manufacturing the catheter according to claim 5, characterized in that, The step of welding the third flange to one end of the cylinder includes: A double V-groove is provided on the cylinder or the third flange, with the larger opening of the double V-groove facing the inside of the cylinder and the smaller opening of the double V-groove facing the outside of the cylinder. Tin foil is pasted on the outer wall of the cylinder, and the projection of the double V-groove along the radial direction of the cylinder onto the outer wall of the cylinder is located on the tin foil; Welding is performed at the double V-groove along the radial outward direction of the cylinder to weld the third flange to one end of the cylinder.

7. The method for manufacturing the catheter according to claim 6, characterized in that, The step of welding the half-pipe to the corresponding main pipe includes: A second V-shaped bevel is machined on the edge of the inner liner plate near the assembly notch; Tin foil is pasted on the inner wall of the inner lining plate, and the projection of the second V-shaped bevel along the radial direction of the inner lining plate onto the inner wall of the inner lining plate is located on the tin foil. Welding is performed at the second V-groove along the radial inward direction of the inner liner to weld the inner liner to the corresponding half-pipe.

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