Welding method

Abstract

The invention provides a welding method which comprises the following steps: feeding: providing a first welding piece and a second welding piece; cutting is conducted, specifically, the cross section of a first welding section, with the first preset length, of the first welding piece is cut down, and the cross section of a second welding section, with the second preset length, of the second welding piece is cut down; overlapping, wherein the first welding section and the second welding section are crossed in the length extension direction of the first welding section and are overlapped together in the transverse direction to form a welding part; welding is conducted, specifically, the welding part is wrapped with molten welding flux through welding equipment; the melting point of the welding flux is lower than that of the first welding piece and that of the second welding piece. The problem that the first welding part and the second welding part are difficult to fuse is solved, meanwhile, the bonding strength between the first welding part and the second welding part is higher, the twisting and bending times of the welding position are increased, the welding length is increased, the welding stress is dispersed, breakage is not prone to occurring, and fatigue durability is enhanced.

Description

Technical Field

[0001] This application belongs to the technical field of guide wire welding, and more specifically, relates to a welding method. Background Art

[0002] A guide wire is a key tool in medical intervention operations, especially widely used in vascular interventions, endoscopic surgeries, or minimally invasive surgeries. The guide wire is usually first inserted into blood vessels and cavities (such as blood vessels, bile ducts, urinary tracts, etc.) to provide a path for subsequent catheters or other instruments (such as stents, balloons).

[0003] The tip of the guide wire is usually made of nitinol alloy material to meet the characteristics of the guide wire being soft and elastic, which can reduce damage to blood vessels or tissues and avoid perforation or spasm. The part of the guide wire other than the tip is generally made of stainless steel material, making the guide wire hard, which is beneficial for the guide wire to be pushed into the blood vessel outside the body and can achieve external control and twisting operations. Therefore, it is necessary to weld the nitinol alloy and the stainless steel material to form the guide wire. However, since the melting point of nickel is 1453 degrees, the melting point of titanium is 1668 degrees, and the melting point of iron is 1535 degrees, this difference in melting temperature is manifested in that when welding the nitinol alloy and stainless steel, the melting points of titanium and nickel in the nitinol are different from that of the stainless steel, and the temperature difference in heat melting and heat curing often leads to difficulty in mutual melting. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a welding method to solve the technical problem of difficult mutual melting when welding a nitinol alloy material and a second welding part in the existing guide wire.

[0005] To achieve the above purpose, the technical solution adopted in this application is: providing a welding method, including the following steps:

[0006] Feeding, providing a first welding part and a second welding part;

[0007] Stock removal, cross-sectionally reducing a first welding section with a first preset length of the first welding part, and cross-sectionally reducing a second welding section with a second preset length of the second welding part;

[0008] Laminating, crossing the first welding section and the second welding section along the length extension direction of the first welding section and laminating them together transversely to form a welding part;

[0009] Welding, coating the molten solder outside the welding part through a welding device; the melting point of the solder is lower than the melting point of the first welding part and the melting point of the second welding part.

[0010] In some embodiments, the first welding part is a nitinol alloy shaft, and the second welding part is a stainless steel shaft.

[0011] In some embodiments, the welding portion is cylindrical;

[0012] and / or, the melting point range of the solder is 650°C - 850°C.

[0013] In some embodiments, the shaving of the material includes:

[0014] Locally grinding the first welding section inward from the outer peripheral surface to form a first grinding surface;

[0015] Locally grinding the second welding section inward from the outer peripheral surface to form a second grinding surface;

[0016] The stacking includes:

[0017] Stacking the first grinding surface and the second grinding surface together so that the first welding section and the second welding section are combined to form a cylindrical welding portion.

[0018] In some embodiments, the first grinding surface is a flat surface, a curved surface or a helical surface, and the second grinding surface is a flat surface, a curved surface or a helical surface.

[0019] In some embodiments, the cross-sectional area of the first welding section after grinding gradually decreases or remains unchanged from the fixed end to the free end; the cross-sectional area of the second welding section after grinding gradually decreases or remains unchanged from the fixed end to the free end.

[0020] In some embodiments, the stacking includes the following steps:

[0021] Providing a socket;

[0022] Inserting the first welding section and the second welding section into the socket from opposite ends of the socket respectively, and stacking them in the socket to form the welding portion;

[0023] The welding includes: melting the solder by a welding device and filling it between the socket and the welding portion.

[0024] In some embodiments, the side wall of the socket has a through groove; the welding includes: filling the molten solder into the socket and the welding portion through the through groove and filling the through groove, so that the socket and the welding portion are welded into one body.

[0025] In some embodiments, the socket is formed by helically winding a stainless steel wire or a nitinol wire.

[0026] In some embodiments, the first welding member includes a first main body section and a first welding section that are connected to each other, the second welding member includes a second main body section and a second welding section, the outer diameters of the first main body section and the second main body section are equal, and after welding, the outer diameter at the socket is greater than the outer diameter of the first main body section; after the welding, the following steps are further included:

[0027] Grind the outer diameter at the socket so that the outer diameter at the socket is the same as the outer diameter of the first main body section.

[0028] The beneficial effects of the welding method provided in this application are as follows: First, the cross-sections of the first welding section of the first welding member and the second welding section of the second welding member are cut, and the first welding section and the second welding section are crossed along the length extension direction of the first welding section and overlapped horizontally. Finally, the solder is melted and coated outside the first welding section and the second welding section to weld the first welding section and the second welding section into one body. With such a design, it is not necessary to perform fusion welding on the first welding member and the second welding member, that is, the problem of difficult fusion between the first welding member and the second welding member is solved. At the same time, through the cross-over and overlapping design of the first welding section and the second welding section, the bonding strength between the first welding member and the second welding member is greater, the number of times of torsion and bending at the welding joint is increased, the welding length is enhanced, the welding stress is dispersed and not easily broken, and the fatigue durability is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 It is an exploded view of the first welding member, the second welding member and the socket in the welding method provided by the embodiment of the present application;

[0031] Figure 2 It is a structural diagram of the first welding member and the second welding member after material cutting in the welding method provided by the embodiment of the present application;

[0032] Figure 3 It is a structural diagram of the first welding member and the second welding member after material cutting in the welding method provided by another embodiment of the present application;

[0033] Figure 4 It is an exploded structural diagram of the first welding member, the second welding member and the socket after material cutting in the welding method provided by the embodiment of the present application;

[0034] Figure 5 Schematic diagram of the assembly structure of the first welded part, the second welded part and the socket part after material cutting in the welding method provided by the embodiment of the present application;

[0035] Figure 6 Schematic cross-sectional view of the assembly structure of the first welded part, the second welded part and the socket part after material cutting in the welding method provided by the embodiment of the present application;

[0036] Figure 7 is Figure 6 Schematic diagram of the enlarged structure of the partial area A in

[0037] Figure 8 Schematic diagram of the structure after welding of the first welded part, the second welded part and the socket part after material cutting in the welding method provided by the embodiment of the present application;

[0038] Figure 9 Schematic diagram of the finished wire product formed by the welding method provided by the embodiment of the present application;

[0039] Figure 10 Schematic diagram of the structure of the welding jig and the welding equipment applied in the welding method provided by the embodiment of the present application.

[0040] Among them, the reference numerals in the figure are as follows:

[0041] 100, the first welded part; 110, the first welding section; 111, the first grinding surface; 112, the free end; 113, the fixed end; 120, the first main body section; 130, the first transition section; 200, the second welded part; 210, the second welding section; 211, the second grinding surface; 220, the second main body section; 230, the second transition section; 300, the socket part; 310, the through groove; 400, the welding part; 500, the welding jig; 600, the welding equipment. Detailed implementation manners

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0044] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0045] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0046] Please refer to Figures 1 to 6 , and now the welding method provided by the embodiment of the present application will be described. This welding method is used to weld the first welding part 100 and the second welding part 200 into one body to make a guide wire.

[0047] The welding method includes the following steps:

[0048] S10 Feeding: Provide the first welding part 100 and the second welding part 200;

[0049] Among them, it should be noted that in this embodiment, the first welding part 100 is a nickel-titanium alloy part, and the second welding part 200 is a stainless steel part. The nickel-titanium alloy part and the stainless steel part are welded with a solder to make a guide wire. In other embodiments, the first welding part 100 and the second welding part 200 may also be two other structural parts that need to be welded together. The melting points of the first welding part 100 and the second welding part 200 may be the same or different, and there is no unique limitation here.

[0050] S40 Material cutting: Cut the cross-section of the first welding section 110 of the first welding part 100 with a first preset length, and cut the cross-section of the second welding section 210 of the second welding part 200 with a second preset length;

[0051] Specifically, please refer to Figure 2 and Figure 3, cross-sectionally reducing the first welding section 110 means cross-sectionally reducing all parts of the first welding section 110 to the same degree or different degrees. The cross-section refers to the cross-section perpendicular to the length direction of the first welding section 110. Cross-sectionally reducing means reducing the cross-sectional area of all parts of the first welding section 110 by removing materials, so that the cross-sectional area of the first welding section 110 of the first welded part 100 is smaller than that of other positions. The meaning of cross-sectionally reducing the second welding section 210 is the same as that of cross-sectionally reducing the first welding section 110.

[0052] S70 Overlay: Cross the first welding section 110 and the second welding section 210 along the length extension direction of the first welding section 110 and overlay them together transversely to form the welding part 400;

[0053] Specifically, please refer to Figure 5 and Figure 6 , through step S40, cross-sectionally reduce the first welding section 110 and the second welding section 210 respectively, so that the first welding section 110 and the second welding section 210 can cross along the length extension direction of the first welded part 100 and overlay together transversely, so that the cross-sectional area formed by the combination of the first welding section 110 and the second welding section 210 can still be close to other positions of the first welded part 100.

[0054] S100 Welding: Coat the molten solder outside the welding part 400 through the welding device 600; the melting point of the solder is lower than the melting point of the first welded part 100 and the melting point of the second welded part 200.

[0055] It should be noted here that the melting point of the solder is lower than the melting point of the first welded part 100 and the melting point of the second welded part 200. Therefore, when the welding device 600 melts the solder, the first welded part 100 and the second welded part 200 will not melt. The molten solder is coated outside the first welding section 110 and the second welding section 210 to weld the first welding section 110 and the second welding section 210 into one body.

[0056] In the welding method according to the embodiments of the present application, first, the cross-sections of the first welding section 110 of the first welding part 100 and the second welding section 210 of the second welding part 200 are cut, and the first welding section 110 and the second welding section 210 are crossed along the length extension direction of the first welding section 110 and superposed transversely. Finally, the solder is melted and coated outside the first welding section 110 and the second welding section 210 to weld the first welding section 110 and the second welding section 210 into one body. With such a design, it is not necessary to perform fusion welding on the first welding part 100 and the second welding part 200, that is, the problem of difficult fusion between the first welding part 100 and the second welding part 200 is solved. At the same time, through the cross-over superposition design of the first welding section 110 and the second welding section 210, the bonding strength between the first welding part 100 and the second welding part 200 is greater, the number of torsional bends at the welding joint is increased, the welding length is enhanced, the welding stress is dispersed and not easily broken, and the fatigue durability is enhanced.

[0057] In some embodiments, please refer to Figures 1 to 7 , the first welding part 100 is a nickel-titanium alloy shaft, the second welding part 200 is a stainless-steel shaft, and the first welding part 100 and the second welding part 200 are welded to form a guide wire.

[0058] In some embodiments, the solder is a silver-based brazing filler metal, such as BAg72Ni or BAg50CuZn. Among them, the silver-based brazing filler metal is usually a hard brazing material mainly based on silver or a silver-based solid solution, and has excellent process performance, such as good wettability, electrical conductivity, thermal conductivity, corrosion resistance and good gap filling ability, and can be used to braze almost all ferrous metals and non-ferrous metals except aluminum, magnesium and other low-melting-point metals.

[0059] In some embodiments, the melting point of the solder is 650°C - 850°C. For example, the melting point of the solder can be 650°C, 670°C, 690°C, 710°C, 730°C, 750°C, 790°C, 810°C, 830°C or 850°C, etc. Among them, by limiting the melting point range of the silver-based brazing filler metal between 650°C and 850°C, when the silver-based brazing filler metal is heated to a molten state, the stainless-steel material and the nickel-titanium alloy material will not melt.

[0060] In some embodiments, please refer to Figure 2 and Figure 3 , the first welding part 100 includes a first welding section 110 and a first main body section 120. The first welding section 110 and the first main body section 120 are connected by a first transition section 130. Before the cross-section of the first welding section 110 is cut, both the first welding section 110 and the first main body section 120 are cylindrical, and the outer diameter of the first welding section 110 is smaller than the outer diameter of the first main body section 120.

[0061] Specifically, the first welded part 100 is ground by means of circumferential grinding to form a first welding section 110, a first transition section 130 and a first main section 120. Before grinding, the outer diameters of all parts of the first welded part 100 are equal to the outer diameter of the first main section 120. After grinding, the outer diameter of the first welding section 110 is smaller than the outer diameter of the first main section 120, and the outer diameter of the first transition section 130 gradually decreases from the first main section 120 to the first welding section 110.

[0062] Similarly, the second welded part 200 includes a second welding section 210 and a second main section 220. The second welding section 210 and the second main section 220 are connected by a second transition section 230. Before cross-section reduction of the second welding section 210, both the second welding section 210 and the second main section 220 are cylindrical, and the outer diameter of the second welding section 210 is smaller than the outer diameter of the second main section 220. The outer diameter of the first welding section 110 is the same as the outer diameter of the second welding section 210, and the outer diameter of the first main section 120 is the same as the outer diameter of the second main section 220. The second welding section 210, the second main section 220 and the second transition section 230 of the second welded part 200 are also formed by means of circumferential grinding, which is not uniquely limited here.

[0063] Optionally, the length range of the first welding section 110 is 2.5 cm - 3.3 cm. For example, the length of the first welding section 110 can be 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, 3.0 cm, 3.1 cm, 3.2 cm or 3.3 cm, etc. The length range of the second welding section 210 is 2.5 cm - 3.2 mm. For example, the length of the second welding section 210 can be 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, 3.0 cm, 3.1 cm, 3.2 cm or 3.3 cm, etc. Among them, the longer the lengths of the first welding section 110 and the second welding section 210 are, the more reliable the welding of the first welded part 100 and the second welded part 200 is. Therefore, on the premise that the lengths of the first welded part 100 and the second welded part 200 permit, the lengths of the first welding section 110 and the second welding section 210 are increased as much as possible.

[0064] In some embodiments, please refer to Figure 6 and Figure 7, after the first welding section 110 and the second welding section 210 are superposed, a cylindrical welding portion 400 is formed, and the outer diameter of the welding portion 400 is smaller than the outer diameters of the first main section 120 and the second main section 220. The first welding section 110 and the second welding section 210 are both cylindrical in shape. After cross-section cutting of the first welding section 110 and the second welding section 210, the first welding section 110 and the second welding section 210 are superposed to form a cylindrical welding portion 400, so that the cross-sectional area of the welding portion 400 will not increase after the first welding section 110 and the second welding section 210 cross, and the overall guide wire after welding can be cylindrical. It can be understood that in other embodiments of the present application, when the first welding section 110 and the second welding section 210 are in a block shape, they can also be in a block shape after the first welding section 110 and the second welding section 210 are superposed.

[0065] In some embodiments, please refer to Figure 2 , Figure 3 and Figure 7 , step S40 of material cutting includes:

[0066] S41: Grind the first welding section 110 locally from the outer peripheral surface inward to form a first grinding surface 111;

[0067] S42: Grind the second welding section 210 locally from the outer peripheral surface inward to form a second grinding surface 211;

[0068] Step S70 of superposition includes:

[0069] Attach the first grinding surface 111 and the second grinding surface 211 so that the first welding section 110 and the second welding section 210 are combined to form a cylindrical welding portion 400.

[0070] It should be noted here that "locally" means grinding the first welding section 110 locally from a part of the outer peripheral surface inward to form the first grinding surface 111, rather than grinding the entire outer surface of the first welding section 110 inward, to avoid the inability to superpose the first welding section 110 and the second welding section 210 due to grinding the entire outer surface.

[0071] Specifically, the first grinding surface 111 is formed by grinding the first welding section 110 inward from the outer peripheral surface, and the cross-section of the first welding section 110 is cut. The second grinding surface 211 is formed by grinding the second welding section 210 inward from the outer peripheral surface, and the cross-section of the second welding section 210 is cut.

[0072] Specifically, in step S70, the first welding section 110 and the second welding section 210 are crossed along the length extension direction of the first welding section 110 and superposed transversely. Specifically, the first grinding surface 111 and the second grinding surface 211 are fitted together so that the first welding section 110 and the second welding section 210 are superposed, and the superposed shape is cylindrical. In this embodiment, by locally grinding the first welding section 110 and the second welding section 210 from the outer peripheral surface to form the first grinding surface 111 and the second grinding surface 211 respectively, the first welding section 110 and the second welding section 210 can be superposed in the direction of fitting through the first grinding surface 111 and the second grinding surface 211, so as to ensure the superposition stability of the first welding section 110 and the second welding section 210, and increase the contact area between the first welding section 110 and the second welding section 210, thereby improving the bonding strength between the two.

[0073] In some embodiments, please refer to Figure 2 and Figure 7 , the first grinding surface 111 is a plane, and the second grinding surface 211 is also a plane. Through the setting of the mutual fitting of the two planes, the combination of the first welding section 110 and the second welding section 210 is simple, and the grinding is simple. It can be understood that in other embodiments of the present application, the first grinding surface 111 can also be a curved surface, a wavy surface or a spiral surface extending along the axial and circumferential directions. Correspondingly, the second grinding surface 211 can also be a curved surface, a wavy surface or a spiral surface extending along the axial and circumferential directions.

[0074] In some embodiments, please refer to Figure 2 , the first welding section 110 has a free end 112 and a fixed end 113. Among them, the fixed end 113 is the end where the first welding section 110 is connected to the first transition section 130, and the free end 112 is the end of the first welding section 110 away from the first transition section 130. The cross-sectional area of the first welding section 110 after grinding gradually increases from the free end 112 to the fixed end 113, and the cross-sectional area of the second welding section 210 after grinding gradually increases from the free end 112 to the fixed end 113. With such a design, the first welding section 110 smoothly transitions and extends from the fixed end 113 to the free end 112, and the second welding section 210 smoothly transitions and extends from the fixed end 113 to the free end 112, reducing the concentrated stress. It can be understood that in other embodiments of the present application, please refer to Figure 3 , it can also be that the cross-sectional area of the first welding section 110 after grinding remains unchanged from the fixed end 113 to the free end 112, and the cross-sectional area of the second welding section 210 after grinding remains unchanged from the fixed end 113 to the free end 112. Of course, in other embodiments, the cross-sectional areas of the first welding section 110 and the second welding section 210 can also first decrease and then increase or first increase and then decrease, and there is no unique limitation here.

[0075] In some embodiments, the first grinding surface 111 is formed with protrusions, and the second grinding surface 211 is formed with grooves, and the protrusions and the grooves are in concave-convex fit. Among them, through the concave-convex fit of the protrusions and the grooves, the bonding strength between the first welding section 110 and the second welding section 210 can be improved, thereby improving the connection strength of the first welding member 100 and the second welding member 200 at the welding joint. It can be understood that in some other embodiments of the present application, it may also be that the first grinding surface 111 is formed with grooves, and the second grinding surface 211 is formed with protrusions, and the protrusions and the grooves are in concave-convex fit, which is not limited uniquely here.

[0076] In some embodiments, please refer to Figures 4 to 6 , step S70 superposition: The first welding section 110 and the second welding section 210 are crossed along the length extension direction of the first welding section 110 and superposed transversely together to form a welding part, including the following steps:

[0077] S71: Provide a socket 300;

[0078] S72: Insert the first welding section 110 and the second welding section 210 into the socket 300 from opposite ends of the socket 300 respectively, and superpose them in the socket 300 to form a welding part 400;

[0079] Welding S100 includes: melting the solder by a welding device 600 and filling it between the socket 300 and the welding part 400.

[0080] Specifically, the setting of the socket 300 can limit the first welding section 110 and the second welding section 210 to a certain extent, so that the first welding section 110 and the second welding section 210 are superposed together as much as possible, and prevent the first welding section 110 and the second welding section 210 from separating before welding. And the setting of the socket 300 can enhance the connection strength between the first welding section 110 and the second welding section 210 to a certain extent, improve the anti-bending ability at the welding joint, and reduce the possibility of fracture at the connection of the first welding section 110 and the second welding section 210. Of course, during assembly, a jig can also be set to improve the efficiency of inserting and aligning the first welding section 110 and the second welding section 210.

[0081] In addition, by filling solder between the socket member 300 and the welding portion 400, the solder can wrap the welding portion 400, that is, wrap and overlap the first welding section 110 and the second welding section 210 together to improve the bonding strength between the two. It can be understood that in other embodiments of the present application, the socket member 300 may not be provided, but other additional jigs can be used to ensure the reliable fitting of the first welding section 110 and the second welding section 210, and solder is coated on the outside of the first welding section 110 and the second welding section 210 to achieve the welding between the first welding section 110 and the second welding section 210.

[0082] Specifically, please refer to Figure 10 , the first welding member 100 and the second welding member 200 can be respectively clamped by the welding jig 500, and the socket member 300, the first welding member 100 and the second welding member 200 are welded above the socket member 300 by the welding device 600.

[0083] In some embodiments, before step S40 of trimming the material and step S70 of laminating, the following steps are further included:

[0084] S50: Ultrasonically clean the first welding section 110 and the second welding section 210 with acetone or absolute ethanol to avoid oil stains and moisture remaining on the first welding section 110 and the second welding section 210, which may cause the welded guide wire to be impure.

[0085] In some embodiments, please refer to Figure 7 , a through groove 310 is formed on the side wall of the socket member 300; the S100 welding includes: filling molten solder between the socket member 300 and the welding portion 400 and filling the through groove 310 via the through groove 310 to weld the socket member 300 and the welding portion 400 into one body. Among them, the setting of the through groove 310, on the one hand, facilitates the entry of solder into the gap between the welding portion 400 and the socket member 300, and on the other hand, can also accommodate the solder so that the socket member 300 and the welding portion 400 are combined into one body. It can be understood that in other embodiments of the present application, the through groove 310 may not be provided on the socket member 300. At this time, solder can be filled between the socket member 300 and the welding portion 400 from both ends of the socket member 300, and this is not limited to a single form.

[0086] In some embodiments, please refer to Figure 4, the socket part 300 is spirally wound by stainless steel wire or nitinol wire. Among them, making the socket part 300 from stainless steel wire or nitinol wire ensures that the socket part 300 will not melt during welding and enables the socket part 300 to become part of the guide wire after welding, playing a role in connecting the nitinol shaft and the stainless steel shaft. In addition, the socket part 300 is spirally wound by a filamentous structure, making the socket part 300 elastic, enabling the socket part 300 to be expanded for the insertion of the first welding part 100 or the second welding part 200, and enabling the socket part 300 to contract to encircle the first welding section 110 and the second welding section 210, so as to limit the first welding section 110 and the second welding section 210. It can be understood that in other embodiments of the present application, the socket part 300 can also be made of a material with a melting point higher than that of the solder.

[0087] Optionally, the socket part 300 is spirally wound by nitinol wire, and the cross-section of the nitinol wire is round and flat, so that the inner diameter of the socket part 300 is relatively large. It can be understood that in other embodiments, the cross-section of the nitinol wire can also be circular. It can be understood that in other embodiments of the present application, the socket part 300 may not be spirally wound by stainless steel wire or nitinol wire, but a thin cylindrical socket part 300 is directly provided, and then a plurality of through grooves 310 are formed on the side wall of the socket part 300 to increase the elasticity of the socket part 300, which is not uniquely limited here.

[0088] Optionally, the length range of the socket part 300 is 2.8 cm - 3.5 cm, specifically it can be 2.8 cm, 2.9 cm, 3.0 cm, 3.1 cm, 3.2 cm, 3.3 cm, 3.4 cm or 3.5 cm. The socket part 300 is sleeved outside the first welding section 110 and the second welding section 210. The longer the length of the socket part 300, the longer the overlapping connection length of the first welding part 100 and the second welding part 200, making the connection between the first welding part 100 and the second welding part 200 more reliable.

[0089] In addition, after step S70 of overlapping, the following steps are further included:

[0090] Step S80: Oxygen isolation protection is carried out on the welding part 400 and the solder to prevent titanium oxidation to the greatest extent, and an argon nozzle is aligned with the socket part 300 outside the welding part 400 and blown for at least 10 seconds to remove the residual oxygen in the socket part 300.

[0091] Specifically, the welding part 400, solder, etc. are all placed in the glove box of the welding device to protect the welding part 400 and the solder from oxygen. An argon nozzle is aligned with the socket part 300 outside the welding part 400, so that argon enters between the socket part 300 and the welding part 400 through the through groove 310 and blows for at least 10 seconds to remove the residual oxygen in the socket part 300.

[0092] In some embodiments, after the cross-sections of the first welding section 110 and the second welding section 210 are cut and overlapped to form the welding part 400, the outer diameter of the welding part 400 is smaller than the outer diameter of the first main body section 120. The socket part 300 is sleeved outside the welding part 400, the first transition section 130 and the second transition section 230. The inner diameter of the socket part 300 is smaller than the outer diameter of the first main body section 120, and the outer diameter of the socket part 300 is larger than the outer diameter of the first main body section 120. In this way, axial limitation of the socket part 300 can be formed by the first main body section 120 and the second main body section 220. In addition, the socket part 300 and the welding part 400 can be welded into one body, making the socket part 300 become a part of the guide wire. And after welding, the outer diameter at the socket part 300 is larger than the outer diameters of the first main body section 120 and the second main body section 220.

[0093] In some embodiments, please refer to Figure 8 and Figure 9 , after welding, the following steps are further included:

[0094] S80: Grind the outer diameter at the socket part 300 so that the outer diameter at the socket part 300 is the same as the outer diameter of the first main body section 120.

[0095] Specifically, because the outer diameter of the socket part 300 is larger than the outer diameters of the first main body section 120 and the second main body section 220, after the solder is filled in the through groove 310 of the socket part 300, the outer diameter at the socket part 300 is relatively larger than the outer diameters of the first main body section 120 and the second main body section 220. At this time, grinding operation is needed to grind the socket part 300 so that the surfaces of all parts of the whole welded product are flat, for example, the outer diameters of all parts of the guide wire are evenly distributed.

[0096] Specifically, the outer surface of the welding position can be polished by a grinding machine so that the outer diameter of the welding position is equal to the outer diameters of other positions.

[0097] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A welding method, characterized in that, It includes the following steps: Feeding, providing a first welding part and a second welding part; Stock removal, cross-sectionally reducing a first welding section of the first welding part with a first preset length and cross-sectionally reducing a second welding section of the second welding part with a second preset length; Lamination, crossing the first welding section and the second welding section along the length extension direction of the first welding section and laminating them together transversely to form a welding part; Welding, covering the outside of the welding part with molten solder through a welding device; the melting point of the solder is lower than the melting point of the first welding part and the melting point of the second welding part.

2. The welding method according to claim 1, characterized in that, The first welding part is a nickel-titanium alloy shaft, and the second welding part is a stainless steel shaft.

3. The welding method according to claim 2, wherein The welding part is cylindrical; And / or, the melting point range of the solder is 650°C - 850°C.

4. The welding method according to claim 2, characterized in that The stock removal includes: Locally grinding the first welding section from the outer peripheral surface inward to form a first grinding surface; Locally grinding the second welding section from the outer peripheral surface inward to form a second grinding surface; The lamination includes: Disposing the first grinding surface and the second grinding surface in contact with each other so that the first welding section and the second welding section are combined to form a cylindrical welding part.

5. The welding method according to claim 4, characterized in that, The first grinding surface is a plane, a curved surface or a spiral surface, and the second grinding surface is a plane, a curved surface or a spiral surface.

6. The welding method according to claim 4, characterized in that, The cross-sectional area of the ground first welding section gradually decreases or remains unchanged from the fixed end to the free end; the cross-sectional area of the ground second welding section gradually decreases or remains unchanged from the fixed end to the free end.

7. The welding method according to any one of claims 2 to 6, characterized in that, In the lamination, it includes the following steps: Providing a socket; Inserting the first welding section and the second welding section into the socket from opposite ends of the socket respectively, and laminating them in the socket to form the welding part; The welding includes: filling the space between the socket and the welding part with molten solder through a welding device.

8. The welding method according to claim 7, characterized in that, The side wall of the socket has a through groove; the welding includes: filling the space between the socket and the welding part and filling the through groove with molten solder so that the socket and the welding part are welded into one body.

9. The welding method according to claim 8, characterized in that, The socket is formed by spirally winding stainless steel wire or nickel-titanium alloy wire.

10. The welding method according to claim 7, characterized in that, The first welding part includes a first main body section and a first welding section connected to each other, the second welding part includes a second main body section and a second welding section, the outer diameters of the first main body section and the second main body section are equal, and after welding, the outer diameter at the socket is greater than the outer diameter of the first main body section; after the welding, it further includes the following steps: Grinding the outer diameter at the socket so that the outer diameter at the socket is the same as the outer diameter of the first main body section.

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