Local vacuum laser welding device

Abstract

The invention provides a local vacuum laser welding device and belongs to the field of vacuum laser welding equipment design, the welding device comprises a vacuum cover and a sealing structure, the vacuum cover is provided with a cover hole opposite to a to-be-welded workpiece, and an assembly ring groove surrounding the cover hole is formed in the end face of the side, facing the to-be-welded workpiece, of a peripheral cover body of the cover hole; the sealing structure comprises an elastic sealing ring piece, the elastic sealing ring piece comprises an embedded ring located on the side, away from the to-be-welded workpiece, of the elastic sealing ring piece, the embedded ring is embedded in the assembling ring groove in an interference mode, the cross section of the assembling ring groove is in an inverted trapezoid shape with the large upper portion and the small lower portion, and the embedded ring is matched with the assembling ring groove in shape. The probability that the elastic sealing ring piece is separated from the vacuum cover under the action of internal and external pressure difference in the welding process is effectively reduced, and meanwhile the probability that circumferential movement or radial rolling is caused by uneven friction force between the elastic sealing ring piece and the workpiece to be welded in the welding process can be effectively reduced; and the vacuum degree is stably maintained in the welding process.

Description

Technical Field

[0001] This invention belongs to the field of vacuum laser welding equipment design technology, and specifically relates to a local vacuum laser welding device. Background Technology

[0002] As equipment in aerospace, deep-sea, and other fields evolves towards larger sizes and higher performance, the demand for large-size and thick metal components continues to rise. Welding, as a key process in the manufacture of large components, directly affects the overall performance of the structure. Laser welding, with its advantages of high energy density, small welding deformation, and good flexibility, has been widely used in aerospace, shipbuilding, automotive, and electronics industries. However, when laser welding is performed in an atmospheric environment, the resulting plasma plume enhances the laser shielding effect, leading to significant absorption of the beam energy, reduced energy transfer efficiency to the workpiece, and a significant decrease in penetration depth. Therefore, laser welding in atmospheric environments is currently mainly suitable for thin and medium-thick plates.

[0003] To improve the energy utilization rate of laser welding, vacuum laser welding technology has been proposed, opening up a new direction for this field. This technology, implemented in a vacuum environment, effectively suppresses the formation of plasma plumes, thereby significantly increasing weld penetration. Furthermore, vacuum laser welding can be performed under low vacuum conditions, resulting in higher welding efficiency and reduced processing costs. Therefore, it shows great promise for thick plate welding in important industrial sectors such as aerospace, automotive, and shipbuilding.

[0004] While full-vacuum laser welding significantly reduces the vacuum level, enabling the welding of thick plate components, constructing a full-vacuum chamber is costly and difficult for large components tens or even hundreds of meters in length. In reality, most components only require welding in localized areas; therefore, localized vacuum laser welding has become the preferred method for large, thick-walled equipment due to its high efficiency, reliability, and cost-effectiveness. This technology boasts low energy consumption, high efficiency, and a small heat-affected zone on the workpiece, making it suitable for aerospace, automotive manufacturing, and precision electronics industries. Its key lies in creating a stable localized vacuum environment in the weld area, preventing the molten pool from contacting air during welding and causing defects such as oxidation, porosity, and slag inclusions. Therefore, the reliability of the sealing structure directly affects the weld quality.

[0005] In existing technologies, the sealing structure of local vacuum welding devices generally uses a single O-ring or rectangular cross-section elastomer sealing material, which is embedded in a single-layer annular groove machined on the end face of the vacuum hood. While this structure is simple and easy to implement, in practical applications, especially in the dynamic sealing welding of large-size, long weld seams, it reveals the following significant drawbacks:

[0006] Traditional O-ring or rectangular elastomeric seals rely solely on interference fit to be pressed into a rectangular groove. When the vacuum pump is started and a pressure difference is created inside and outside the cover, the elastomeric seal can be drawn into the cover, either entirely or partially, resulting in a suction-out phenomenon. Under dynamic sealing conditions where the vacuum cover moves along the weld seam, the elastomeric seal is more prone to circumferential movement or radial rolling due to uneven friction. This not only leads to uneven distribution of sealing pressure but also causes abnormal wear between the side of the elastomeric seal and the groove wall, accelerating seal failure and making it impossible to maintain a stable vacuum level during welding. Summary of the Invention

[0007] Therefore, the present invention provides a local vacuum laser welding device that can overcome the shortcomings of existing local vacuum welding devices, which use a single O-ring or rectangular cross-section elastomer sealing material that is pressed into the rectangular groove of the vacuum chamber by interference fit. When there is a pressure difference between the inside and outside of the vacuum chamber during vacuum welding, the sealing structure is prone to suction or detachment, or circumferential movement or radial rolling under uneven friction, resulting in sealing failure and unstable vacuum level.

[0008] To address the aforementioned problems, this invention provides a local vacuum laser welding apparatus, comprising a vacuum hood and a sealing structure. The vacuum hood has a hood aperture positioned opposite to the workpiece to be welded. An assembly ring groove is formed on the outer periphery of the hood facing the workpiece. The sealing structure includes an elastic sealing ring, which includes an insert ring on the side furthest from the workpiece. The insert ring is interference-fitted into the assembly ring groove. The cross-section of the assembly ring groove is an inverted trapezoid, wider at the top and narrower at the bottom. The insert ring is adapted to the shape of the assembly ring groove.

[0009] In some embodiments, a filling ring cavity is formed within the insert ring, the filling ring cavity extending along the circumferential direction of the insert ring, and the filling ring cavity is used to fill a pressure medium.

[0010] In some embodiments, the outer peripheral cover has a positioning through hole extending to the end face of the part away from the workpiece to be welded, and the insert ring has a filling tube inserted into the positioning through hole, the filling tube communicating with the cavity of the filling ring.

[0011] In some embodiments, there are two filling tubes, which are located on opposite sides of the cover hole.

[0012] In some embodiments, the local vacuum laser welding apparatus further includes an active cooling circulation component, which includes a cooling component, a circulating pressurizing pump, a return pipe, and an inlet pipe. The return pipe is connected to one of the filling pipes, and the inlet pipe is connected to the other filling pipe. The pressure medium is cooling water, and the circulating pressurizing pump is used to circulate the cooling water under pressure between the cooling component and the filling ring cavity via the return pipe and the inlet pipe.

[0013] In some embodiments, there are two resilient sealing rings arranged inner and outer layers along the radial direction of the cover hole, and the embodiment further includes an active cooling circulation component that simultaneously provides a pressure medium to both resilient sealing rings.

[0014] In some embodiments, the elastic sealing ring further includes a separating sealing ring on the side of the ring closest to the workpiece to be welded. The separating sealing ring has a fixing groove formed on its end face facing the workpiece to be welded, which extends through the inner and outer sides of the separating sealing ring along a first straight line direction. The assembly also includes a weld sealing strip assembly, which has two sets. Each set of the weld sealing strip assembly is respectively embedded in the fixing groove of two adjacent separating sealing rings in the same area, and the length extension direction of each set of the weld sealing strip assembly is parallel to the first straight line direction.

[0015] In some embodiments, the weld sealing strip assembly includes a sealing strip and a high-temperature resistant elastic gasket attached to the end face of the sealing strip facing the workpiece to be welded.

[0016] In some embodiments, a first anti-slip structure is formed between the insert ring and the groove sidewall of the assembly ring groove; a second anti-slip structure is formed between the filling tube and the mating wall surface of the positioning through hole.

[0017] In some embodiments, the first anti-slip structure includes a plurality of first anti-detachment rings formed on the sidewall of the assembly ring groove and a plurality of second anti-detachment rings formed on the ring wall of the insert ring. Each of the first and second anti-detachment rings extends around the circumference of the cover hole, and each of the first and second anti-detachment rings alternates sequentially along the depth direction of the cover hole to form a concave-convex fit. The second anti-slip structure includes a plurality of third anti-detachment rings formed on the outer wall of the filling tube and a plurality of fourth anti-detachment rings formed on the inner wall of the positioning through hole. Each of the third and fourth anti-detachment rings extends around the circumference of the positioning through hole, and each of the positioning through holes alternates sequentially along the depth direction to form a concave-convex fit.

[0018] The local vacuum laser welding device provided by this invention has the following beneficial effects:

[0019] The embedded ring of the elastic sealing ring is adapted to the inverted trapezoidal groove structure of the assembly ring groove of the vacuum shroud, thus objectively forming a wedge-shaped anti-detachment structure. For example, the narrowing structure of the assembly ring groove forms a mechanical anchor for the top embedded part of the elastic sealing ring, effectively reducing the probability of the elastic sealing ring detaching from the vacuum shroud under the action of internal and external pressure difference during the welding process. At the same time, it can also effectively reduce the probability of circumferential movement or radial rolling caused by uneven friction between the elastic sealing ring and the workpiece to be welded during the welding process, ensuring that the vacuum degree is maintained stably during the welding process. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is an exploded three-dimensional structural diagram of the local vacuum laser welding device of the present invention in one embodiment;

[0022] Figure 2 yes Figure 1 A schematic cross-sectional view of the assembled local vacuum laser welding device shown.

[0023] Figure 3 yes Figure 2 A schematic diagram of the vacuum chamber structure in one cross-section;

[0024] Figure 4 yes Figure 2 A schematic diagram of the cross-section of the elastic sealing ring component;

[0025] Figure 5 This is an exploded three-dimensional structural diagram of the local vacuum laser welding device of the present invention in another embodiment;

[0026] Figure 6 yes Figure 5 A schematic cross-sectional view of the assembled local vacuum laser welding device shown.

[0027] Figure 7 yes Figure 6 A magnified view of a portion of point A in the middle.

[0028] The attached figures are labeled as follows:

[0029] 1. Vacuum shroud; 11. Outer shroud; 111. Assembly ring groove; 12. Shroud hole; 121. Positioning through hole; 2. Elastic sealing ring; 21. Embedded ring; 211. Filling ring cavity; 212. Filling tube; 22. Separating sealing ring; 221. Fixing groove; 31. Refrigeration component; 32. Circulating pressurizing pump; 33. Return pipe; 34. Inlet pipe; 41. Sealing strip; 42. High-temperature resistant elastic gasket; 51. First anti-slip structure; 52. Second anti-slip structure; 61. Laser incident tube; 62. Vacuum extraction port; 63. Vacuum resistance gauge tube; 64. Resistance gauge tube fixing tube; 65. Laser incident window lens; 66. Lens pressure plate; 67. O-ring seal; 68. Connecting screw. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0032] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0033] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0034] See also Figures 1 to 7 As shown, according to an embodiment of the present invention, a local vacuum laser welding apparatus is provided, including a vacuum chamber 1 and a sealing structure (not shown in the figure). The vacuum chamber 1 has a cover hole 12 disposed opposite to the workpiece to be welded (not shown in the figure). See details below. Figure 1 As shown, on the side of the vacuum chamber 1 away from the workpiece to be welded, a laser incident tube 61 and a laser incident window lens 65 are sequentially arranged along the direction away from the workpiece. The laser incident tube 61 has connecting flanges at both ends (not labeled in the figure). The connecting flange at the lower end of the laser incident tube 61 is detachably connected to the vacuum chamber 1 by corresponding connecting screws 68. The laser incident window lens 65 is specifically fixed to the connecting flange at the upper end of the laser incident tube 61 by a lens clamping plate 66. In actual use… A corresponding laser welding head (i.e., a laser generating component, not shown in the figure) is also configured on the top end face of the lens pressure plate 66 (i.e., the end face away from the workpiece to be welded). It is understood that the central hole of the aforementioned laser incident tube 61 is the laser incident channel. Simultaneously, a vacuum port 62 communicating with the central hole is formed on the side wall of the laser incident tube 61. Through the aforementioned vacuum port 62, it is controllably connected to an external vacuum component (e.g., a vacuum pump), thereby achieving the formation of a local vacuum environment for laser welding. See details... Figure 1As shown, a resistance gauge fixing tube 64 is connected to the vacuum port 62. This tube can be designed as a tee, with a vacuum resistance gauge 63 assembled and fixed on one port to monitor the real-time vacuum level of the formed local vacuum environment. To ensure the stability of the vacuum level, corresponding O-ring seals 67 are also provided between the assembly surfaces of the corresponding components. The outer periphery of the cover 11 of the cover hole 12 faces the end face of the workpiece to be welded (i.e.,...). Figure 1 An assembly ring groove 111 is formed on the bottom surface (shown in the indicated direction) surrounding the cover hole 12. The sealing structure includes an elastic sealing ring 2, that is, the elastic sealing ring 2 is made entirely of a material with a certain degree of elasticity. The elastic sealing ring 2 includes an insert ring 21 on the side away from the workpiece to be welded. The insert ring 21 is interference-fitted into the assembly ring groove 111. The cross-section of the assembly ring groove 111 is an inverted trapezoid with a larger upper section and a smaller lower section (see also...). Figures 1 to 3 (See the orientation diagram in the image). The embedded ring 21 is shaped to match the assembly ring groove 111. It is understood that the size and shape of the embedded ring 21 also match the size and shape of the cross-section of the assembly ring groove 111; that is, the cross-section of the embedded ring 21 is an inverted trapezoid, wider at the top and narrower at the bottom. It should be noted that, due to the high temperatures generated during welding, the aforementioned elastic sealing ring 2 should be made of a high-temperature resistant elastic material, generally capable of withstanding temperatures of at least 200℃-600℃.

[0035] In this technical solution, the embedded ring 21 of the elastic sealing ring 2 is adapted to the inverted trapezoidal groove structure of the assembly ring groove 111 of the vacuum shroud 1, thereby objectively forming a wedge-shaped anti-detachment structure. For example, the narrowing structure of the assembly ring groove 111 forms a mechanical anchoring of the top embedded part of the elastic sealing ring 2, effectively reducing the probability of the elastic sealing ring 2 detaching from the vacuum shroud 1 under the action of internal and external pressure difference during the welding process. At the same time, it can also effectively reduce the probability of circumferential movement or radial rolling caused by uneven friction between the elastic sealing ring 2 and the workpiece to be welded during the welding process, ensuring that the vacuum degree is maintained stably during the welding process.

[0036] In some embodiments, a filling annular cavity 211 (i.e., an annular connecting cavity extending at least one circumference along the insert ring 21) is formed within the insert ring 21. The filling annular cavity 211 extends along the circumferential direction of the insert ring 21 and is used to fill a pressure medium. The aforementioned pressure medium can be gaseous, liquid, or even solid particles that can be applied under the high-temperature operating conditions. In principle, it is sufficient that the filling medium can cause outward extrusion deformation of the outer wall of the filling annular cavity 211.

[0037] In this technical solution, by setting a filling ring cavity 211 in the insert ring 21, the filling ring cavity 211 can be filled with a corresponding pressure medium, so that it can expand and deform under the outward extrusion of the pressure medium, thereby improving the connection reliability and stability of the insert ring 21 in the assembly ring groove 111. It is understandable that when the aforementioned insert ring 21 adopts a solid structure, in order for its wedge-shaped structure, which is larger at the top and smaller at the bottom, to be smoothly inserted into the assembly ring groove 111 of the constricted structure in an interference fit, the difference between the large size of the insert ring 21 and the small size of the assembly ring groove 111 should not be too large. Generally, the vacuum cover 1 needs to be heated when assembling the elastic sealing ring 2. By forming a hollow structure, namely the aforementioned filling ring cavity 211, in the insert ring 21, it can be ensured that the filling ring cavity 211 is in a hollow state before assembly. Since there is no pressure medium in the filling ring cavity 211, the insert ring 21 has a greater deformation capacity (it can shrink in size under external force) and is more easily inserted into the assembly ring groove 111. After being inserted into the assembly ring groove 111, pressure medium is then filled into the filling ring cavity 211 to improve the deformation resistance of the insert ring 21, thereby making it closely matched with the assembly ring groove 111 and improving the anti-dislodgement effect of the elastic sealing ring 2.

[0038] In some embodiments, the outer peripheral cover 11 has a positioning through hole 121 extending to the end face away from the workpiece to be welded (i.e., extending to the upper and lower end faces of the outer peripheral cover 11). The insert ring 21 has a filling tube 212 inserted into the positioning through hole 121. The filling tube 212 communicates with the filling ring cavity 211. It is understood that in some embodiments, a plug (not shown in the figure) is also provided at the opening of the filling tube 212 to close the corresponding opening of the filling tube 212 after the pressure medium is filled.

[0039] In this technical solution, the filling tube 212 is inserted into the positioning through hole 121 of the vacuum shroud 1. On the one hand, the filling tube 212 can be used to fill the filling ring cavity 211 of the embedded ring 21 in the embedded state with the corresponding pressure medium to achieve the final positioning of the embedded ring 21. On the other hand, the insertion and cooperation between the filling tube 212 and the positioning through hole 121 can further improve the positioning stability of the elastic sealing ring 2.

[0040] In some embodiments, there are two filling tubes 212, which are respectively located on opposite sides of the cover hole 12. By providing one filling tube 212 on each opposite side of the cover hole 12, the elastic sealing ring 2 can be positioned at two points on the left and right ends in one direction, ensuring the stress balance of the overall structure.

[0041] For details, please refer to [link / reference]. Figure 5 and Figure 6 As shown, in some embodiments, the local vacuum laser welding apparatus further includes an active cooling circulation component (not labeled in the figure). The active cooling circulation component includes a cooling component 31, a circulating pressurizing pump 32, a return pipe 33, and an inlet pipe 34. The return pipe 33 is connected to one of the filling pipes 212, and the inlet pipe 34 is connected to another filling pipe 212. The pressure medium is cooling water. The circulating pressurizing pump 32 is used to form a pressure circulation of the cooling water between the cooling component 31 and the filling ring cavity 211 through the return pipe 33 and the inlet pipe 34. The aforementioned cooling component 31 can be, for example, an air-cooled heat exchanger or a water-cooled heat exchanger, which can cool the pressure medium flowing within it. In a specific embodiment, the aforementioned cooling component 31 includes a cooling water tank and a cooling device (such as a semiconductor cooling component) assembled on the cooling water tank. The cooling water flows into the cooling water tank under the action of the aforementioned circulating pressurizing pump 32 and is cooled and dissipated.

[0042] In this technical solution, cooling water is used as the aforementioned pressure medium. While utilizing its positive pressure to achieve outward expansion deformation of the aforementioned embedded ring 21 to ensure the anti-detachment performance of the elastic sealing ring 2, the cooling water can also be circulated and cooled by an active cooling circulation component. This significantly reduces the temperature rise of the elastic sealing ring 2 and the vacuum chamber 1, and simplifies the material selection for the elastic sealing ring 2 and the vacuum chamber 1. It is understood that the pumping pressure of the aforementioned circulating pressurization pump 32 can be reasonably determined based on the cooling requirements and the pressure requirements of the pressure medium.

[0043] In some embodiments, there are two elastic sealing rings 2, which are arranged in an inner and outer layer along the radial direction of the cover hole 12 (i.e., forming an inner and outer double layer). The embodiment also includes an active cooling circulation component that simultaneously provides a pressure medium for the two elastic sealing rings 2, thereby simplifying the structural design. In some embodiments, the center-to-center distance between the inner and outer elastic sealing rings 2 is 0.1-150 mm.

[0044] In this technical solution, two layers of elastic sealing rings 2, inner and outer, are provided on the end face of the vacuum chamber 1, surrounding the chamber hole 12. This can form an independent double-layer sealing barrier in the radial direction of the chamber hole 12, ensuring the stable maintenance of the vacuum degree at the chamber hole 12 through redundant protection. If one of the elastic sealing rings 2 leaks locally due to wear, scratches, or accidental contamination, the other layer of seal can still independently maintain the effective vacuum degree, greatly improving the overall reliability of the sealing structure and greatly reducing the risk of welding process interruption caused by single-point failure.

[0045] In some embodiments, the elastic sealing ring 2 further includes a separating sealing ring 22 located on its side closer to the workpiece to be welded. In one specific embodiment, the cross-section of the aforementioned separating sealing ring 22 is rectangular, having a large bottom plane that allows for a large contact sealing area with the workpiece to be welded. The end face of the separating sealing ring 22 facing the workpiece to be welded has a section extending along a first straight direction through both its inner and outer sides (e.g., ...). Figure 1 The fixing groove 221 (shown on the left and right sides) also includes a weld sealing strip assembly (not indicated in the figure). The weld sealing strip assembly has two sets, each set being embedded in the fixing groove 221 of two adjacent separating sealing rings 22 in the same area. The length extension direction of each set of weld sealing strip assemblies is parallel to the first straight line direction. The weld sealing strip assembly can be connected to the fixing groove 221 by adhesive bonding, for example, to reliably seal the weld reinforcement formed by welding. Generally, the weld sealing strip assembly has a large overall deformation capacity, while the elastic sealing ring 2 has strong resistance to deformation to prevent large deformation caused by the pressure difference between its inner and outer sides. The aforementioned embedding ring 21 and separating sealing ring 22 can be bonded together, or they can be integrally formed through molding, vulcanization, or other processes.

[0046] In this technical solution, a corresponding fixing groove 221 is formed on the bottom end face of the elastic sealing ring 2, and the weld sealing strip assembly is fixed in the fixing groove 221. The weld sealing strip assembly can form an adaptive (morphological adaptive) compensation effect by relying on its own large deformation capacity to ensure that its bottom surface is tightly fitted with the weld protrusion surface (i.e., the weld height), ensuring the continuity of the sealing interface along the entire length of the weld, and eliminating the periodic air leakage and vacuum fluctuation caused by the weld height.

[0047] In some embodiments, the upper base length of the aforementioned insert ring 21 is 0.1-300mm and the lower base length is 0.1-250mm, the lateral width of the rectangular cross section of the aforementioned separating sealing ring 22 is 0.1-250mm, and the overall total height of the elastic sealing ring 2 is 0.1-180mm. Of course, the specific size selection can be reasonably matched according to the size of the vacuum hood 1.

[0048] In one specific implementation, the weld sealing strip assembly includes a sealing strip 41 and a high-temperature resistant elastic gasket 42 connected to the end face of the sealing strip 41 facing the workpiece to be welded, in order to improve its service life. Generally, in order to match the operating temperature of the laser welding process, the high-temperature resistant elastic gasket 42 can withstand a temperature of 1000℃-1800℃. In this technical solution, the weld sealing strip assembly is composed of a sealing strip 41 made of elastomeric sealing material at the top and a high-temperature resistant elastic gasket 42 at the bottom. Its overall thickness can be adjusted according to the actual working conditions. During the welding process, the vacuum hood 1 is tightly pressed into the top surface of the workpiece to be welded. During this process, the elastomeric sealing material base adapts to the workpiece's base plane, while the high-temperature resistant elastic gasket is specifically used to fill the gaps on both sides of the protrusion caused by the weld reinforcement, thereby ensuring the continuity of the sealing interface along the entire length of the weld and eliminating periodic air leakage and vacuum fluctuations caused by the reinforcement. The aforementioned high-temperature resistant elastic gasket 42 is firmly attached to the inner surface of the bottom side of the aforementioned sealing strip 41 by a high-temperature resistant adhesive. It directly faces the high-temperature heat radiation and molten pool splash. With its excellent thermal stability and ablation resistance, it effectively blocks the transfer of heat to the sealing strip 41 and the aforementioned elastic sealing ring 2, preventing the main body of the sealing structure from failing due to high-temperature softening or decomposition.

[0049] In some embodiments, the width (i.e., the dimension perpendicular to the aforementioned first straight line direction) of the aforementioned weld sealing strip assembly is 0.1-200 mm, and the overall height is 0.1-150 mm. The thickness ratio of the adaptable elastomeric sealing material and the high-temperature resistant elastic gasket can be adjusted according to the excess height of the weld to be welded. It is understood that after the weld sealing strip assembly is assembled in the aforementioned fixing groove 221, its bottom end face (i.e., the end face near the workpiece to be welded) should be on the same plane as the bottom end face of the elastic sealing ring 2.

[0050] The length of the aforementioned weld sealing strip assembly is much greater than the wall thickness of the elastic sealing ring 2, thus enabling it to form a longer matching fit with the weld. This length matching helps to improve its tight fit with the outer wall of the weld reinforcement, ensuring the sealing effect at the weld position. When the aforementioned elastic sealing ring 2 adopts two layers, the wall thickness of the outer elastic sealing ring 2 is d1, the wall thickness of the inner elastic sealing ring 2 is d2, and the radial distance between the ring walls of the inner and outer elastic sealing ring 2 is d3. Then, the length L of the weld sealing strip assembly is greater than d1 + d2 + d3, and both ends protrude from the inner side of the inner elastic sealing ring 2 and the outer side of the outer elastic sealing ring 2, respectively.

[0051] The outer peripheral cover 11 also has an auxiliary limiting groove (not indicated in the figure) on the end face near the workpiece to be welded, which can accommodate the top end face of the aforementioned weld sealing strip assembly. The width and extension direction of each of the auxiliary limiting grooves are consistent with those of the aforementioned fixing groove 221.

[0052] In some embodiments, a first anti-slip structure 51 is formed between the insert ring 21 and the groove sidewall of the assembly ring groove 111. The first anti-slip structure 51 includes a plurality of first anti-detachment rings formed on the groove sidewall of the assembly ring groove 111 and a plurality of second anti-detachment rings formed on the ring wall of the insert ring 21. Each first anti-detachment ring and each second anti-detachment ring extends around the circumference of the cover hole 12, and each first anti-detachment ring and each second anti-detachment ring intersects sequentially along the depth direction of the cover hole 12. The filling tube 212 and the positioning through hole 121 are interlocked to form a concave-convex fit; a second anti-slip structure 52 is formed between the mating wall surfaces of the filling tube 212 and the positioning through hole 121. The second anti-slip structure 52 includes multiple third anti-detachment rings formed on the outer tube wall of the filling tube 212 and multiple fourth anti-detachment rings formed on the inner wall of the positioning through hole 121. Each of the third and fourth anti-detachment rings extends around the circumference of the positioning through hole 121, and the depth direction of each positioning through hole 121 is staggered to form a concave-convex fit.

[0053] In this technical solution, the aforementioned first anti-slip structure 51 and second anti-slip structure 52 utilize their respective anti-detachment rings to form a concave-convex fit structure. On the one hand, this can improve the friction and fastening force between two adjacent mating parts, improve the positional reliability of the elastic sealing ring 2, and effectively prevent the anti-detachment phenomenon. On the other hand, it can form a labyrinth sealing effect for airflow or pressure medium fluid, ensure the stable position of vacuum, and prevent pressure medium leakage.

[0054] In summary, the design mechanism of this invention is based on the synergistic principle of "mechanical anchoring - elastic fit - redundant barrier - morphological self-adaptation". Through structural innovation and material properties, it systematically solves the dynamic sealing problem in local vacuum welding. Its core lies in the use of a double-layer elastomeric sealing material structure with a trapezoidal and rectangular composite cross section. Specifically, the trapezoidal upper bottom (i.e., the aforementioned insert ring 21) and the double-layer concentric annular trapezoidal groove (i.e., the aforementioned assembly ring groove 111) precisely machined on the end face of the vacuum cover form an interference fit, constituting reliable mechanical anchoring. This structure fundamentally resists the tendency of the elastomeric sealing material to be sucked into the cover during vacuuming, and effectively restricts the circumferential movement and radial rolling of the elastomeric sealing material in the groove when the vacuum cover moves along the weld seam, ensuring the geometric stability of the dynamic sealing process. The rectangular bottom (i.e., the aforementioned separating sealing ring 22) serves as the main sealing function. Its wide design can produce uniform and sufficient elastic deformation under vacuum negative pressure, closely fitting the surface of the workpiece to be welded, and achieving sealing even in the face of microscopic unevenness. Furthermore, the double-layered concentrically arranged inner and outer sealing rings (i.e., the two elastic sealing rings 2 arranged in the inner and outer layers) constitute two independent sealing barriers, forming redundant protection. When the outer layer seal experiences local leakage due to wear, scratches, or accidental contamination, the inner layer seal can still independently maintain an effective vacuum, greatly improving the overall reliability of the sealing system and avoiding the risk of welding process interruption due to single-point failure. The use of a pressure-filled medium makes the connection between each elastic sealing ring 2 and the vacuum chamber 1 more reliable and stable. For the specific condition of weld excess height, the rectangular sealing material running through the double-layered sealing rings plays a crucial adaptive compensation role. Through the above-mentioned multi-level collaborative mechanism, this invention achieves stable and reliable sealing from static to dynamic states, and from planar surfaces to surfaces with excess height, providing a key foundation for high-quality local vacuum laser welding.

[0055] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A local vacuum laser welding apparatus, characterized in that, The system includes a vacuum hood (1) and a sealing structure. The vacuum hood (1) has a hood hole (12) that is disposed opposite to the workpiece to be welded. An assembly ring groove (111) is formed on the end face of the outer circumferential hood body (11) of the hood hole (12) facing the workpiece to be welded. The sealing structure includes an elastic sealing ring (2). The elastic sealing ring (2) includes an insert ring (21) on the side away from the workpiece to be welded. The insert ring (21) is interference-fitted into the assembly ring groove (111). The cross-section of the assembly ring groove (111) is an inverted trapezoid with a larger upper section and a smaller lower section. The shape of the insert ring (21) is adapted to the shape of the assembly ring groove (111).

2. The local vacuum laser welding apparatus according to claim 1, characterized in that, A filling ring cavity (211) is formed inside the insert ring (21), the filling ring cavity (211) extends along the circumferential direction of the insert ring (21), and the filling ring cavity (211) is used to fill pressure medium.

3. The local vacuum laser welding apparatus according to claim 2, characterized in that, The outer cover (11) has a positioning through hole (121) extending to the end face of the side away from the workpiece to be welded. The insert ring (21) has a filling tube (212) inserted into the positioning through hole (121). The filling tube (212) is connected to the filling ring cavity (211).

4. The local vacuum laser welding apparatus according to claim 3, characterized in that, There are two filling tubes (212), which are located on opposite sides of the cover hole (12).

5. The local vacuum laser welding apparatus according to claim 4, characterized in that, It also includes an active cooling circulation component, which includes a refrigeration component (31), a circulation booster pump (32), a return pipe (33) and an inlet pipe (34). The return pipe (33) is connected to one of the filling pipes (212), and the inlet pipe (34) is connected to the other filling pipe (212). The pressure medium is cooling water. The circulation booster pump (32) is used to form a pressure circulation of the cooling water between the refrigeration component (31) and the filling ring cavity (211) through the return pipe (33) and the inlet pipe (34).

6. The local vacuum laser welding apparatus according to claim 5, characterized in that, The elastic sealing ring (2) has two members, which are arranged in the inner and outer layers along the radial direction of the cover hole (12), and the active cooling circulation component provides a pressure medium for both elastic sealing rings (2).

7. The local vacuum laser welding apparatus according to claim 6, characterized in that, The elastic sealing ring (2) also includes a separating sealing ring (22) located on the side of it close to the workpiece to be welded. The separating sealing ring (22) has a fixing groove (221) formed on the end face facing the workpiece to be welded, which runs through the inner and outer sides of the separating sealing ring (22) along a first straight line direction. It also includes a weld sealing strip assembly. The weld sealing strip assembly has two sets. Each set of the weld sealing strip assembly is respectively embedded in the fixing groove (221) of two adjacent separating sealing rings (22) in the same area, and the length extension direction of each set of the weld sealing strip assembly is parallel to the first straight line direction.

8. The local vacuum laser welding apparatus according to claim 7, characterized in that, The weld sealing strip assembly includes a sealing strip (41) and a high-temperature resistant elastic gasket (42) connected to the end face of the sealing strip (41) facing the workpiece to be welded.

9. The local vacuum laser welding apparatus according to claim 3, characterized in that, A first anti-slip structure (51) is formed between the insert ring (21) and the groove sidewall of the assembly ring groove (111); a second anti-slip structure (52) is formed between the filling tube (212) and the mating wall of the positioning through hole (121).

10. The local vacuum laser welding apparatus according to claim 9, characterized in that, The first anti-slip structure (51) includes multiple first anti-detachment rings formed on the sidewall of the assembly ring groove (111) and multiple second anti-detachment rings formed on the ring wall of the insert ring (21). Each first anti-detachment ring and each second anti-detachment ring extends around the circumference of the cover hole (12), and each first anti-detachment ring and each second anti-detachment ring alternately forms a concave-convex fit along the depth direction of the cover hole (12). The second anti-slip structure (52) includes multiple third anti-detachment rings formed on the outer tube wall of the filling tube (212) and multiple fourth anti-detachment rings formed on the inner wall of the positioning through hole (121). Each third anti-detachment ring and each fourth anti-detachment ring extends around the circumference of the positioning through hole (121), and each positioning through hole (121) alternately forms a concave-convex fit along the depth direction of the hole.

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