Titanium alloy oil receiving rod laser welding device and method

Abstract

This invention provides a laser welding device and method for titanium alloy oil receiving rods, belonging to the field of aircraft component welding technology. The titanium alloy oil receiving rod is formed by sequentially connecting a first, second, and third split component, with two circumferential welds using a lock-bottom butt joint structure. The welding device achieves coaxial clamping of the two circumferential weld centers through a three-jaw chuck, clamping ring, and cross-air connection structure. After forming a sealed body with a cap, argon gas is injected to protect the back of the weld. During welding, an inert gas is used to protect the front of the weld through a side-blowing nozzle, and photo-induced plasma is suppressed. The welding head attitude, height, and welding speed are kept stable through linkage control between a robotic arm and a rotary positioner. The circumferential weld area can be prefabricated as a structure of uniform wall thickness to be welded, and then precision machined after welding to achieve the target variable wall thickness structure. This invention can reduce the risks of welding oxidation, porosity, and deformation, and improve the welding quality and forming accuracy of the oil receiving rod.

Description

Technical Field

[0001] This invention belongs to the field of aircraft component welding technology, specifically relating to a laser welding device and method for titanium alloy oil receiving rods. Background Technology

[0002] As one of the physical carriers for aerial refueling, the design and manufacturing process of the refueling boom focuses on high performance, lightweight, and low cost. To better meet the service performance requirements of this type of structure, a titanium alloy refueling boom with a specific topology was designed based on aerodynamic analysis results. Local structures were reinforced and their bending resistance was improved, achieving high performance and lightweight. However, this presented challenges to the manufacturing process. Conventional forging and casting processes are difficult to use to manufacture the topology-optimized thin-walled irregular structure refueling boom. Although additive manufacturing technology is theoretically feasible, the titanium alloy refueling boom, with a length exceeding 1.2m, requires a large additive manufacturing machine, resulting in high overall manufacturing costs. Furthermore, the large aspect ratio thin-walled irregular structure additive parts require deep heat treatment, making deformation prone to exceed limits. At the same time, the shaping of titanium alloy structural parts is extremely difficult, and manufacturing precision seriously affects the aerodynamic performance of the structure.

[0003] In existing laser welding solutions for circumferential seams of tubular components, some methods create an inert gas atmosphere on the weld front side using a gas shield or shielding gas input pipe. However, these solutions typically lack effective inert gas protection for the weld back side, i.e., the inner wall of the pipe, making it difficult to meet the welding protection requirements of oxidation-sensitive materials such as titanium alloys. Furthermore, during laser deep penetration welding, photo-induced plasma is easily generated in the welding area. Without effective plasma suppression measures, the welding process can easily become unstable. Another approach uses a vacuum welding chamber to control the weld front and back sides, as well as the photo-induced plasma. However, the vacuum welding chamber requires a high-vacuum pump, a vacuum monitoring system, and a dedicated vacuum motion mechanism, resulting in high equipment costs. Moreover, the processes of vacuuming, cooling, and hoisting and clamping heavy components are time-consuming, leading to low welding efficiency. Additionally, the fixed dimensions of the vacuum chamber and poor spatial expandability make it difficult to flexibly adapt to large aspect ratio irregular oil-receiving rod structures. Therefore, existing technologies still lack a laser welding device and method that can simultaneously provide weld front and back protection, photo-induced plasma suppression, and high-precision clamping and positioning of irregular titanium alloy oil-receiving rods under normal pressure conditions. Summary of the Invention

[0004] In view of the defects in the existing technology and the characteristics of titanium alloy oil receiving rods, such as large length-to-diameter ratio, thin walls, and irregular structure, the present invention provides a laser welding device and method for titanium alloy oil receiving rods.

[0005] The titanium alloy oil receiving rod laser welding device provided by the present invention is used to clamp and weld a titanium alloy oil receiving rod comprising a first split component, a second split component, and a third split component connected in sequence, wherein the second split component is an intermediate split component. Circumferential welds are formed between the first and second sub-components, and between the second and third sub-components, respectively. The titanium alloy oil receiving rod laser welding device includes: a chuck mechanism, a clamping and positioning mechanism, an end sealing mechanism, and an inert gas supply mechanism; The chuck mechanism includes a first three-jaw chuck and a second three-jaw chuck that are arranged opposite to each other along the length of the titanium alloy oil receiving rod. The first three-jaw chuck is located on the side of the first split component that faces away from the second split component. The second and third jaw chucks are located on the side of the third component opposite to the second component; The clamping and positioning mechanism includes a first clamp and a second clamp. The first clamp is used to hold the first split component and is connected to the first three-jaw chuck. The second clamp is used to hold the third split component and is connected to the second three-jaw chuck; The end sealing mechanism includes a first cap and a second cap. The first cap is used to close the free end of the first split component. The second cap is used to close the free end of the third component. The first cap, the second cap, the first split component, the second split component, and the third split component together form a closed body; The inert gas supply mechanism is connected to the enclosure and is used to introduce inert gas into the enclosure. The annular center of the first clamp, the annular center of the second clamp, the centers of both ends of the second split component, the center of the first three-jaw chuck, and the center of the second three-jaw chuck are coaxial.

[0006] Preferably, both the first three-jaw chuck and the second three-jaw chuck include a disc-shaped chuck body and three jaws disposed on the disc-shaped chuck body. The three jaws are spaced apart circumferentially along the corresponding disc-shaped chuck body and are capable of moving radially along the corresponding disc-shaped chuck body. The three jaws of the first three-jaw chuck are used to clamp the connecting end of the first clamp. The three jaws of the second three-jaw chuck are used to clamp the connecting end of the second clamp.

[0007] Preferably, both the first clamp and the second clamp are annular clamps. The annular clamp includes an annular clamping portion, which forms a clamping hole for accommodating the straight segment of the corresponding split component. The inner circumferential surface of the clamping hole is adapted to the outer circumferential surface of the corresponding straight segment of the split part.

[0008] Preferably, the annular clamping part has an open annular structure. Locking lugs are formed on both sides of the opening of the annular structure. The locking lugs are connected by fasteners to adjust the clamping degree of the clamping hole.

[0009] Preferably, the first clamp is held in the clamping section of the first split component, and avoids the circumferential weld between the first split component and the second split component by 10mm; The second clamp is held in the clamping section of the third component, avoiding the circumferential weld seam between the second component and the third component by 10mm.

[0010] Preferably, the first cap and / or the second cap are provided with an air inlet structure communicating with the enclosure, the air inlet structure being used to introduce an inert gas into the enclosure; the inert gas is argon, and the argon gas is introduced into the enclosure through the second cap.

[0011] Preferably, the titanium alloy oil-receiving rod laser welding device further includes a front protection and plasma suppression mechanism. The front protection and plasma suppression mechanism includes a side-blowing nozzle. The side-blowing nozzle is fixedly mounted on the laser welding head. The nozzle port of the side-blowing nozzle is suspended behind the laser aperture, and the suspension height between the nozzle port and the workpiece surface is 2mm to 5mm. The nozzle axis of the side-blowing nozzle is tilted forward relative to the welding trajectory, and the angle between the nozzle axis and the welding trajectory is approximately 60°. The side-blowing nozzle is used to blow protective gas into the laser welding molten pool area to protect the weld front and suppress the photo-induced plasma.

[0012] A laser welding method for titanium alloy oil-receiving rods according to the present invention is implemented using a laser welding apparatus for titanium alloy oil-receiving rods according to the present invention. The laser welding method for titanium alloy oil-receiving rods includes: Step S1: Welding joint preparation; The first, second, and third parts are prepared using additive manufacturing processes. Locking grooves are machined at both ends of the second part, so that the end of the first part near the second part and the end of the third part near the second part form locked bottom ends. Two elliptical or circular circumferential welds are formed between the first, second, and third parts. Step S2: Assemble and align the split components; Assemble the first, second, and third split components onto the titanium alloy oil receiving rod laser welding device, clamp the titanium alloy oil receiving rod laser welding device onto the first and second three-jaw chucks connected to the rotary positioner, make the second split component horizontal, and make the center of both end faces of the second split component collinear with the center of the first and second three-jaw chucks, and then seal both ends of the titanium alloy oil receiving rod with the first and second caps respectively; Step S3: Inert gas filling; Argon gas is filled into the titanium alloy oil receiving rod through the second cap to purge the air inside the titanium alloy oil receiving rod, so as to protect the back of the weld during welding; Step S4: Spot welding; Using laser welding, the laser beam is perpendicular to the workpiece surface to spot weld and fix the two circumferential welds between the first split part, the second split part and the third split part. The spot welding length is about 10mm. Step S5: Welding; Using laser welding, the laser beam is perpendicular to the workpiece surface to weld the two circumferential seam lock bottom joints from step S4 completely. Step S6: Heat treatment; The oil-bearing rod welded in step S5 is subjected to stress-relieving heat treatment.

[0013] Preferably, in step S1, the first, second, and third parts are all additively manufactured parts; the joints of the two circumferential welds are both lock-bottom butt joints, and the two ends of the second part are respectively provided with lock-bottom grooves. The end of the first part near the second part and the end of the third part near the second part are both lock-bottom ends, which cooperate with the lock-bottom grooves at both ends of the second part to form lock-bottom butt circumferential welds. In step S5, a laser welding method is used to make the laser beam perpendicular to the workpiece surface to complete the welding of the two circumferential weld joints in step S4. During the welding process, protective gas is blown into the laser welding molten pool area through the side blow nozzle fixed to the laser welding head to protect the front of the weld and suppress the photo-induced plasma. At the same time, the laser welding head is always perpendicular to the workpiece surface where the circumferential weld is located through the linkage control of the robotic arm and the rotary positioner, and the height between the laser welding head and the workpiece surface is kept consistent.

[0014] Preferably, in step S5, the circumferential seam lock bottom welding adopts a two-dimensional oscillating laser welding process. The process parameters of the two-dimensional oscillating laser welding process are: laser power P=4000W, welding speed v=1m / min, defocusing amount δ=0mm, oscillation frequency f=300Hz, and amplitude r=0.5mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves the technical effect of transforming a large aspect ratio thin-walled irregular oil receiving rod into a segmented welding structure suitable for circumferential laser welding by splitting the titanium alloy oil receiving rod into three separate parts and forming two lock-bottom butt circumferential welds between adjacent parts, thereby facilitating subsequent coaxial clamping, back protection and continuous laser welding. 2. By setting two circumferential welds at approximately 1 / 3 and 2 / 3 of the length of the oil-receiving rod and designing the cross-sections of the two circumferential welds with a concentric axis, this invention achieves the technical effect of similar welding trajectories for the two circumferential welds, thereby reducing the difficulty of clamping and trajectory control in laser welding of circumferential welds of irregular tubular structures. 3. The present invention avoids the beginning and end ends of the oil receiving rod by using the first clamp and the second clamp, and makes the center of the two circumferential welds coaxial with the center of the first three-jaw chuck and the second three-jaw chuck through the cross-air connection structure. This achieves the technical effect of positioning without relying on the beginning and end ends of the shaped tube, thereby solving the problem of difficulty in rotational displacement caused by the non-concentricity of the beginning and end ends of the shaped tube. 4. The present invention achieves the technical effect of reducing the risk of oxidation in titanium alloy welding and improving the stability of laser welding under normal pressure by using argon filling inside the sealed body for backside protection and using side-blowing nozzles for inert gas protection and photo-induced plasma suppression on the front side of the weld. 5. This invention achieves the technical effects of stable welding head posture, height, and welding speed, as well as consistent heat input in the welding area, through the linkage control of the robotic arm and rotary positioner, combined with the technical features of the circumferential weld seam area with equal wall thickness to be welded and the post-weld variable wall thickness precision machining, thereby improving the welding quality and forming accuracy of the elliptical variable wall thickness circumferential weld seam. Attached Figure Description

[0016] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the first segment of the device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the third segment of the device embodiment of the present invention; Figure 3 This is a schematic diagram of the oil-receiving rod clamping state according to an embodiment of the present invention.

[0017] The diagram shows: Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0019] like Figures 1 to 3 As shown, this invention provides a laser welding device for titanium alloy oil receiving rods, particularly suitable for 3D printing irregularly shaped tubular elliptical titanium alloy structural parts with varying wall thickness; used for clamping and welding titanium alloy oil receiving rods comprising a first split part 1, a second split part 2, and a third split part 3 connected in sequence, wherein the second split part is an intermediate split part; wherein, circumferential welds are formed between the first split part 1 and the second split part 2, and between the second split part 2 and the third split part 3, respectively, and the shape of the circumferential welds is elliptical or circular. Specifically, the first split part 1... Part 1, Part 2, and Part 3 are all additively manufactured parts, and are assembled after heat treatment and necessary finishing to form a titanium alloy oil receiving rod to be welded. The joints of the two circumferential welds are both lock-bottom butt joints. Lock-bottom grooves are provided at both ends of Part 2. The ends of Part 1 and Part 3 near Part 2 are both lock-bottom ends, respectively, and cooperate with the lock-bottom grooves at both ends of Part 2 to form lock-bottom butt circumferential welds. In a more specific embodiment, applicable to 3D printing irregularly shaped tubular variable-wall-thickness elliptical titanium alloy structural parts, the two circumferential welds are respectively located at approximately 1 / 3 and 2 / 3 of the length of the titanium alloy oil receiving rod, and the cross-sections of the two circumferential welds are designed with concentric axes, making the welding trajectories of the two circumferential welds similar. This reduces the requirement for the height of the 3D printed forming cavity and facilitates subsequent rotational displacement welding. In another more specific embodiment, for cases where the base material thickness at the circumferential weld is 2mm to 4mm with varying wall thickness, the circumferential weld area is first prefabricated as a structure to be welded with a uniform wall thickness of 4mm; after the two circumferential welds are welded, the welded parts are then precisely processed according to the 2mm to 4mm varying wall thickness model.

[0020] This invention provides a method for laser welding of titanium alloy oil receiving rods, which is implemented using the titanium alloy oil receiving rod laser welding device provided in this invention. The titanium alloy oil receiving rod laser welding device includes: a jaw mechanism, a clamping and positioning mechanism, an end sealing mechanism, and an inert gas supply mechanism.

[0021] The aforementioned jaw mechanism includes: a first three-jaw chuck 4 and a second three-jaw chuck 5 arranged opposite to each other; the first three-jaw chuck 4 and the second three-jaw chuck 5 are arranged opposite to each other along the length direction of the titanium alloy oil receiving rod, and are respectively located on the outer sides of both ends of the titanium alloy oil receiving rod; that is: the first three-jaw chuck 4 is located on the side of the first split part 1 away from the second split part 2, and the second three-jaw chuck 5 is located on the side of the third split part 3 away from the second split part 2. The first three-jaw chuck 4 and the second three-jaw chuck 5 each include a disc-shaped chuck body and three jaws arranged on the disc-shaped chuck body. The three jaws are arranged circumferentially at intervals along the corresponding disc-shaped chuck body and can move radially along the corresponding disc-shaped chuck body; the three jaws of the first three-jaw chuck 4 are used to clamp the connecting end of the first clamp 8, and the three jaws of the second three-jaw chuck 5 are used to clamp the connecting end of the second clamp 9; the first three-jaw chuck 4 and the second three-jaw chuck 5 are also used as clamping and positioning references, and drive the titanium alloy oil receiving rod to rotate around its length direction under rotational drive.

[0022] The aforementioned clamping and positioning mechanism includes: a first clamp 8 and a second clamp 9. The first clamp 8 is used to clamp the first split component 1 and is connected to the first three-jaw chuck 4; the second clamp 9 is used to clamp the third split component 3 and is connected to the second three-jaw chuck 5. Specifically, both the first clamp 8 and the second clamp 9 are annular clamps, and the annular clamping part has an inner circumferential surface that is adapted to the outer circumferential surface of the corresponding split component. That is, both the first clamp 8 and the second clamp 9 include an annular clamping part, which surrounds a clamping hole for accommodating the clamping section of the corresponding split component. The inner circumferential surface of the clamping hole is adapted to the outer circumferential surface of the clamping section of the corresponding split component. The annular clamping part is an open annular structure, and locking ears are formed on both sides of the opening of the open annular structure and connected by fasteners to adjust the clamping degree of the clamping hole. In a more specific embodiment, preferably, the first clamp 8 and the second clamp 9 both avoid the adjacent locking bottom butt weld seam by approximately 10 mm. Thus, the first clamp 8 and the second clamp 9 can radially clamp and position the first split component 1 and the third split component 3 while avoiding the locking bottom butt weld seam, ensuring the coaxiality of the assembly of the first split component 1, the second split component 2, and the third split component 3. In a specific implementation, the first clamp 8 and the second clamp 9 do not use the beginning and end ends of the titanium alloy oil receiving rod as the positioning reference. Instead, they avoid the beginning and end ends and are connected to the first three-jaw chuck 4 and the second three-jaw chuck 5 respectively through a cross-connection structure, so that the center of the two circumferential weld seams is on the same axis as the center of the first three-jaw chuck 4 and the second three-jaw chuck 5. Therefore, for irregularly shaped tubular oil receiving rods with misaligned beginning and end ends, it is not necessary to use the beginning and end ends as the rotation positioning reference. Instead, the center of the two circumferential weld seams is directly used as the welding rotation reference, thereby simplifying rotation displacement control and improving the coaxiality accuracy of the circumferential weld seam clamping.

[0023] The aforementioned end-sealing mechanism includes a first cap 6 and a second cap 7. The first cap 6 closes the free end of the first split component 1, and the second cap 7 closes the free end of the third split component 3. The first cap 6, the second cap 7, the first split component 1, the second split component 2, and the third split component 3 form a complete closed body. The first cap 6 and / or the second cap 7 are provided with an air inlet structure communicating with the closed body, so that an inert gas supply mechanism is connected to the closed body to introduce inert gas into the closed body to protect the back side of the circumferential weld between the first split component 1 and the second split component 2 and the circumferential weld between the second split component 2 and the third split component 3 during welding. In a more specific embodiment, the inert gas is argon gas, which is introduced into the closed body through the second cap 7. By introducing inert gas into the closed body, the air inside the closed body can be discharged, and the back side of the two lock-bottom butt circumferential welds can be protected during the welding process.

[0024] Furthermore, the annular center of the first clamp 8, the annular center of the second clamp 9, the centers of both ends of the second split component 2, the center of the first three-jaw chuck 4, and the second three-jaw chuck 5 are concentric. The first three-jaw chuck 4 and the second three-jaw chuck 5 serve as clamping and positioning references, ensuring that the centers of the first clamp 8, the second clamp 9, and the centers of the two end faces of the second split component 2 remain concentric or collinear. During welding, under rotary drive, the first three-jaw chuck 4 and the second three-jaw chuck 5 can drive the titanium alloy oil receiving rod to rotate around its length direction to cooperate with the laser beam to complete the continuous welding of the two circumferential welds.

[0025] Furthermore, in one specific embodiment, the titanium alloy oil-receiving rod laser welding apparatus further includes a front protection and plasma suppression mechanism (not shown in the figure). The front protection and plasma suppression mechanism includes a side-blowing nozzle, which is fixedly mounted on the laser welding head and moves synchronously with it. The nozzle port of the side-blowing nozzle is suspended behind the laser aperture, with a suspension height of 2mm to 5mm between the nozzle port and the workpiece surface. The lower edge profile of the nozzle port is set as a plane or a contoured arc surface according to the surface shape of the object to be welded; when the circumferential weld to be welded is a circular or elliptical circumferential weld, the lower edge profile of the nozzle port is set as a contoured arc surface adapted to the surface of the circumferential weld. The nozzle axis of the side-blowing nozzle is tilted forward relative to the welding trajectory, and the angle between the nozzle axis and the welding trajectory is approximately 60°. During welding, the side-blowing nozzle blows a protective gas into the laser welding molten pool area; the protective gas is preferably pure argon, and the gas flow rate is 50L / min to 60L / min. The protective gas blown out by the aforementioned side-blowing nozzle covers the laser welding molten pool and the surrounding high-temperature area with a temperature of over 400°C, providing inert gas protection for the weld front. At the same time, the protective gas blown out by the forward-tilting nozzle can physically impact and suppress the photo-induced plasma generated during the welding process, thereby improving the stability of the laser welding process.

[0026] Furthermore, in one specific embodiment, the titanium alloy oil-receiving rod laser welding device also includes a welding execution mechanism (not shown in the figure). This welding execution mechanism includes a robotic arm, a laser welding head, and a control unit. The laser welding head is disposed at the end of the robotic arm, and the control unit is communicatively connected to both the robotic arm and the rotary positioner. For circular or elliptical circumferential welds, the control unit controls the robotic arm posture and the rotary positioner rotation speed according to a preset circumferential weld trajectory, ensuring that the laser welding head maintains a laser beam perpendicular to the workpiece surface where the circumferential weld is located throughout the welding process, and that the height between the laser welding head and the workpiece surface remains consistent. When the circumferential weld is elliptical, the control unit controls the rotation speed of the rotary positioner according to the welding position of the laser welding head on the elliptical circumferential weld, ensuring that the welding speed of the laser welding head moving along the elliptical circumferential weld remains uniform, thereby guaranteeing consistent defocusing, stable welding speed, and stable weld formation.

[0027] The laser welding method for titanium alloy oil-receiving rods provided in this embodiment of the invention includes: Step S1: Welding joint preparation; First component 1, second component 2 and third component 3 are prepared by additive manufacturing process. Locking grooves are machined at both ends of the second component 2, so that the end of the first component 1 near the second component 2 and the end of the third component 3 near the second component 2 are respectively locked bottom ends. Two elliptical or circular circumferential welds are formed between the first component 1, the second component 2 and the third component 3.

[0028] Step S2: Assemble and align the split components; Assemble the first split component 1, the second split component 2, and the third split component 3 onto the welding device; Clamp the welding device onto the first three-jaw chuck 4 and the second three-jaw chuck 5 connected to the rotary positioner, so that the second split component 2 is in a horizontal state, and the center of both end faces of the second split component 2 is collinear with the center of the first three-jaw chuck 4 and the second three-jaw chuck 5; The first cover 6 and the second cover 7 respectively seal the two ends of the titanium alloy oil receiving rod; Step S3: Inert gas filling; Argon gas is filled into the titanium alloy oil receiving rod through the second cap 7 to purge the air inside the titanium alloy oil receiving rod, so as to protect the back of the weld during welding; Specifically, before welding, argon gas can be introduced into the sealed body through the second cap 7 to purge the air inside the sealed body and fill the sealed body with argon gas.

[0029] Step S4: Spot welding; Laser welding, with the laser beam perpendicular to the workpiece surface, spot welds the two circumferential welds between the first split part 1, the second split part 2 and the third split part 3, with a spot weld length of about 10mm.

[0030] Step S5: Welding; Laser welding, with the laser beam perpendicular to the workpiece surface, completes the welding of the two circumferential seam lock bottom joints from step S4; Specifically, laser welding is used, with the laser beam perpendicular to the workpiece surface, to complete the welding of the two circumferential seam lock bottom joints from step S4; During the welding process, protective gas is blown into the laser welding molten pool area through a side-blowing nozzle fixed to the laser welding head to protect the weld front and suppress the photo-induced plasma; Simultaneously, through the linkage control of the robotic arm and the rotary positioner, the laser welding head is always perpendicular to the workpiece surface where the circumferential weld is located, and the height between the laser welding head and the workpiece surface is kept consistent.

[0031] Step S6: Heat treatment; Stress relief heat treatment is performed on the oil-bearing rod that was welded in step S5.

[0032] In a more specific embodiment, in step S5 above, for the elliptical circumferential weld, the robotic arm and rotary positioner are linked and controlled according to the preset elliptical circumferential weld trajectory. The rotary positioner adjusts its rotation speed according to the welding position to keep the welding speed along the elliptical circumferential weld uniform. The circumferential weld bottom locking welding adopts a two-dimensional oscillating laser welding process with the following parameters: laser power P=4000W, welding speed v=1m / min, defocusing amount δ=0mm, oscillation frequency f=300Hz, and amplitude r=0.5mm. The protective gas blown by the side-blowing nozzle is pure argon, with a gas flow rate of 50L / min to 60L / min. The suspension height between the nozzle port and the workpiece surface is 2mm to 5mm. The nozzle axis of the side-blowing nozzle is tilted forward relative to the welding trajectory, and the angle between the nozzle axis and the welding trajectory is approximately 60°.

[0033] In summary, this invention reduces the manufacturing difficulty of thin-walled, irregularly shaped titanium alloy oil receiving rods with large aspect ratios by dividing them into a first component 1, a second component 2, and a third component 3, and then combining them using a lock-bottom butt weld. Concentric clamping and positioning are achieved through a first three-jaw chuck 4, a second three-jaw chuck 5, a first clamp 8, and a second clamp 9. An internal inert gas protective environment is formed by a first cover 6, a second cover 7, and an inert gas supply mechanism, ensuring assembly accuracy and protecting the back of the weld. The front of the weld is protected by a side-blowing nozzle, and photo-induced plasma is suppressed. Stable welding head posture, height, and welding speed are ensured through the linkage control of a robotic arm and a rotary positioner. Combined with two-dimensional oscillating laser welding and post-weld stress-relieving heat treatment, the risks of welding oxidation, porosity, and deformation are reduced, improving welding quality and the forming accuracy of the oil receiving rod.

[0034] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not 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 application.

[0035] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A laser welding device for titanium alloy oil-receiving rods, characterized in that, The titanium alloy oil receiving rod, consisting of a first split part (1), a second split part (2), and a third split part (3) connected in sequence, is used for clamping and welding. The second split part (2) is the intermediate split part. A circumferential weld is formed between the first split component (1) and the second split component (2), and between the second split component (2) and the third split component (3). The titanium alloy oil receiving rod laser welding device includes: a chuck mechanism, a clamping and positioning mechanism, an end sealing mechanism, and an inert gas supply mechanism; The chuck mechanism includes a first three-jaw chuck (4) and a second three-jaw chuck (5) arranged opposite each other along the length of the titanium alloy oil receiving rod. The first three-jaw chuck (4) is located on the side of the first split part (1) that is away from the second split part (2). The second three-jaw chuck (5) is located on the side of the third split part (3) away from the second split part (2); The clamping and positioning mechanism includes a first clamp (8) and a second clamp (9). The first clamp (8) is used to hold the first split component (1) and is connected to the first three-jaw chuck (4). The second clamp (9) is used to hold the third split part (3) and is connected to the second three-jaw chuck (5); The end sealing mechanism includes a first cap (6) and a second cap (7). The first cap (6) is used to close the free end of the first split component (1). The second cap (7) is used to close the free end of the third component (3). The first cap (6), the second cap (7), the first split component (1), the second split component (2), and the third split component (3) together form a closed body; The inert gas supply mechanism is connected to the enclosure and is used to introduce inert gas into the enclosure. The annular center of the first clamp (8), the annular center of the second clamp (9), the two end centers of the second split part (2), the center of the first three-jaw chuck (4), and the center of the second three-jaw chuck (5) are coaxial.

2. The laser welding device for titanium alloy oil-receiving rods according to claim 1, characterized in that, The first three-jaw chuck (4) and the second three-jaw chuck (5) both include a disc-shaped chuck body and three jaws disposed on the disc-shaped chuck body. The three jaws are arranged circumferentially around the corresponding disc-shaped chuck body and can move radially around the corresponding disc-shaped chuck body. The three jaws of the first three-jaw chuck (4) are used to clamp the connecting end of the first clamp (8). The three jaws of the second three-jaw chuck (5) are used to clamp the connecting end of the second clamp (9).

3. The laser welding device for titanium alloy oil-receiving rods according to claim 1, characterized in that, Both the first clamp (8) and the second clamp (9) are annular clamps. The annular clamp includes an annular clamping portion, which forms a clamping hole for accommodating the straight segment of the corresponding split component. The inner circumferential surface of the clamping hole is adapted to the outer circumferential surface of the corresponding straight segment of the split part.

4. The laser welding device for titanium alloy oil-receiving rods according to claim 3, characterized in that, The annular clamping part has an open annular structure. Locking lugs are formed on both sides of the opening of the annular structure. The locking lugs are connected by fasteners to adjust the clamping degree of the clamping hole.

5. The laser welding device for titanium alloy oil-receiving rods according to claim 1, characterized in that, The first clamp (8) is clamped in the clamping section of the first split part (1) and avoids the circumferential weld between the first split part (1) and the second split part (2) by 10mm; The second clamp (9) is held in the clamping section of the third split part (3) and avoids the circumferential weld 10mm between the second split part (2) and the third split part (3).

6. The laser welding device for titanium alloy oil receiving rods according to claim 1, characterized in that, The first cover (6) and / or the second cover (7) are provided with an air inlet structure communicating with the enclosure, the air inlet structure being used to introduce an inert gas into the enclosure; the inert gas is argon, and the argon gas is introduced into the enclosure through the second cover (7).

7. The laser welding device for titanium alloy oil-receiving rods according to claim 1, characterized in that, It also includes front protection and plasma suppression mechanisms. The front protection and plasma suppression mechanism includes a side-blowing nozzle. The side-blowing nozzle is fixedly mounted on the laser welding head. The nozzle port of the side-blowing nozzle is suspended behind the laser aperture, and the suspension height between the nozzle port and the workpiece surface is 2mm to 5mm. The nozzle axis of the side-blowing nozzle is tilted forward relative to the welding trajectory, and the angle between the nozzle axis and the welding trajectory is approximately 60°. The side-blowing nozzle is used to blow protective gas into the laser welding molten pool area to protect the weld front and suppress the photo-induced plasma.

8. A laser welding method for titanium alloy oil-receiving rods, characterized in that, The titanium alloy oil-receiving rod laser welding apparatus according to any one of claims 1 to 7 is used, and the titanium alloy oil-receiving rod laser welding method includes: Step S1: Welding joint preparation; The first split part (1), the second split part (2) and the third split part (3) are prepared by additive manufacturing process respectively. Locking grooves are processed at both ends of the second split part (2) so that the end of the first split part (1) close to the second split part (2) and the end of the third split part (3) close to the second split part (2) respectively form the locked bottom end. Two elliptical or circular circumferential welds are formed between the first split part (1), the second split part (2) and the third split part (3). Step S2: Assemble and align the split parts; Assemble the first split part (1), the second split part (2) and the third split part (3) onto the titanium alloy oil receiving rod laser welding device, clamp the titanium alloy oil receiving rod laser welding device onto the first three-jaw chuck (4) and the second three-jaw chuck (5) connected to the rotary positioner, so that the second split part (2) is in a horizontal state, and make the center of the two end faces of the second split part (2) collinear with the center of the first three-jaw chuck (4) and the second three-jaw chuck (5), and then seal the two ends of the titanium alloy oil receiving rod with the first cap (6) and the second cap (7) respectively; Step S3: Inert gas filling; Argon gas is filled into the titanium alloy oil receiving rod through the second cap (7) to vent the air inside the titanium alloy oil receiving rod, so as to protect the back of the weld during welding; Step S4: Spot welding; Using laser welding, the laser beam is perpendicular to the workpiece surface to spot weld and fix the two circumferential welds between the first split part (1), the second split part (2) and the third split part (3), with a spot welding length of about 10mm. Step S5: Welding; Using laser welding, the laser beam is perpendicular to the workpiece surface to weld the two circumferential seam lock bottom joints from step S4 completely. Step S6: Heat treatment; The oil-bearing rod welded in step S5 is subjected to stress-relieving heat treatment.

9. The laser welding method for titanium alloy oil-receiving rods according to claim 8, characterized in that, In step S1, the first split part (1), the second split part (2), and the third split part (3) are all additive manufacturing parts; the joints of the two circumferential welds are all locked bottom butt joints. The two ends of the second split part (2) are respectively provided with locking bottom grooves. The end of the first split part (1) near the second split part (2) and the end of the third split part (3) near the second split part (2) are both used as the locked bottom ends, which cooperate with the locking bottom grooves at both ends of the second split part (2) to form a locked bottom butt circumferential weld. In step S5, a laser welding method is used to make the laser beam perpendicular to the workpiece surface to complete the welding of the two circumferential weld joints in step S4. During the welding process, protective gas is blown into the laser welding molten pool area through the side blow nozzle fixed to the laser welding head to protect the front of the weld and suppress the photo-induced plasma. At the same time, the laser welding head is always perpendicular to the workpiece surface where the circumferential weld is located through the linkage control of the robotic arm and the rotary positioner, and the height between the laser welding head and the workpiece surface is kept consistent.

10. The laser welding method for titanium alloy oil-receiving rods according to claim 8 or claim 9, characterized in that, In step S5, the circumferential seam lock bottom welding adopts a two-dimensional oscillating laser welding process. The process parameters of the two-dimensional oscillating laser welding process are: laser power P=4000W, welding speed v=1m / min, defocusing amount δ=0mm, oscillation frequency f=300Hz, and amplitude r=0.5mm.

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