Near-vertical narrow-gap laser welding device and method based on coaxial wire feeding process

Abstract

The invention discloses a near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process. The device is mainly composed of a supporting frame, a self-adaptive clamping mechanism and a welding mechanism. The self-adaptive clamping mechanism adopts the design of multiple auxiliary supporting rods and can be dynamically adjusted in the vertical direction so as to adapt to workpieces in different geometrical shapes. A vacuum chuck is integrated at the upper end of the auxiliary supporting rod, and a cooling air hole is formed in the auxiliary supporting rod and used for achieving local temperature control of a welding area. The welding mechanism is provided with a coaxial wire feeding welding module, multiple layers of concentric annular gas channels are arranged on the periphery of the coaxial wire feeding welding module, and a stable laminar flow protection gas curtain can be formed. According to the near-vertical narrow gap welding method, the metal wires are deposited layer by layer in the near-vertical direction, the long-track reciprocating motion of a welding tool between the starting point and the ending point is remarkably reduced, the interlayer cooling time is shortened, and the technological process is simplified. And meanwhile, uniform thermal circulation can be achieved, and the uniformity of the welding seam structure and the mechanical property is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of narrow-gap welding, and particularly to a near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process. Background Art

[0002] In the field of welding large-thickness workpieces, traditional welding techniques such as gas metal arc welding (GMAW) and tungsten inert gas welding (TIG) have many limitations, including insufficient penetration ability, high process complexity, excessive heat-affected zone (HAZ), and severe residual stress and deformation. These limitations not only reduce the welding efficiency but also affect the mechanical properties and dimensional accuracy of the welded joints. To solve these problems, narrow-gap laser welding technology has emerged. By designing a narrow-gap groove form, this technology significantly reduces the amount of filler material used and simultaneously reduces the heat input, thereby effectively improving the welding efficiency and suppressing deformation and residual stress during the welding process. With its characteristics of high efficiency, precision, and low deformation, narrow-gap laser welding technology provides an advanced solution for large-thickness workpieces.

[0003] Traditional narrow-gap horizontal welding technology faces the following key challenges in practical applications: First, due to the differences in the thermal cycle process of each layer of the weld, the weld microstructure and properties are non-uniform, which affects the overall reliability and mechanical property consistency of the welded joint. Second, after each layer of welding is completed, the welding tool needs to be repositioned. Especially in the scenario of welding long welds, the welding tool must move repeatedly between the starting point and the ending point, which not only increases the process complexity and time cost but also significantly reduces the production efficiency, making it difficult to meet the urgent needs of modern manufacturing for high-efficiency and high-quality welding. These problems severely restrict the wide application of traditional narrow-gap horizontal welding technology in the fields of high-precision and high-efficiency welding and urgently need to be solved through technological innovation.

[0004] In recent years, the coaxial wire feeding process has been gradually applied and promoted in the welding field. Coaxial wire feeding laser welding technology significantly improves the light-wire coupling efficiency by arranging the laser beam and the welding wire coaxially, making the wire melting more sufficient and uniform, and effectively reducing the heat input. Particularly importantly, this technology solves the directional limitation problem existing in traditional off-axis wire feeding welding, providing new possibilities for the innovation of welding processes. Based on this technical advantage, the near-vertical narrow-gap welding method has emerged. By depositing the metal wire layer by layer along the near-vertical direction with a welding tool, this method significantly shortens the interlayer welding path and reduces the cooling time, thus avoiding the problems of uneven heat treatment and microstructure property fluctuations caused by excessive interlayer cooling time in traditional horizontal welding.

[0005] Compared with horizontal welding, the near-vertical narrow-gap welding method exhibits significant advantages in multiple aspects. Firstly, vertical welding deposits the wire layer by layer in an upright manner, reducing the repeated movement of the welding tool between the starting and ending points. This not only simplifies the process flow but also significantly reduces the time cost and improves production efficiency. Secondly, the interlayer starting temperature and heating conditions in vertical welding are easier to precisely control, enabling a more uniform thermal cycle, thereby enhancing the uniformity of the weld microstructure and the consistency of mechanical properties. In contrast, due to the long interlayer cooling time and large differences in starting temperatures in horizontal welding, it is difficult to ensure the consistency of the thermal cycle, easily leading to fluctuations in weld performance. Additionally, the near-vertical welding method also has obvious advantages in reducing heat input, welding deformation, and residual stress, providing reliable technical support for high-precision and high-quality welding. Summary of the Invention

[0006] Objective of the present invention: Aiming at the deficiencies of the above-mentioned existing technologies, to solve the problems of non-uniform weld microstructure properties and complex process flow in narrow-gap laser welding, a near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process are provided. A near-vertical narrow-gap welding method is adopted, and an adaptive clamping tool and a multi-layer concentric ring gas channel are additionally added to achieve high-efficiency and high-quality welding of narrow-gap workpieces.

[0007] The objective of the present invention is achieved as follows:

[0008] The near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process includes a support frame, and an adaptive clamping mechanism is arranged above the support frame.

[0009] The adaptive clamping mechanism consists of multiple auxiliary support rods.

[0010] The auxiliary support rods can be dynamically adjusted in the vertical direction to automatically adapt to workpieces with different geometries, ensuring high-precision positioning and stability of the workpiece during the welding process.

[0011] The upper end of the auxiliary support rod is integrated with a vacuum chuck, and the workpiece is rigidly fixed through the vacuum adsorption force, effectively preventing displacement or thermal deformation during the welding process.

[0012] Cooling air holes are provided inside the auxiliary support rod for directional spraying of cooling gas to achieve local temperature control.

[0013] A narrow-gap groove is machined on the surface of the workpiece, and an angle auxiliary metal block is arranged at one end of the groove. A preset inclination angle is formed between the metal block and the groove.

[0014] A welding mechanism is arranged above the workpiece. The welding mechanism works in coordination with a high-precision robotic arm. The welding mechanism includes a coaxial wire feeding welding module, and the welding wire and the laser beam are coaxially arranged.

[0015] The periphery of the coaxial wire feeding welding module is provided with multiple layers of concentric ring gas channels, forming a laminar protective gas curtain to achieve efficient isolation and protection of the welding area.

[0016] The gas channels are composed of multiple independent gas layers. The outer gas channel uses inert gas for environmental isolation, and the inner gas channel selects active gas or mixed gas according to the characteristics of the welding material to enhance the protection effect; the gas flow rate of each gas layer can be independently regulated to adapt to different welding process parameters and ensure the stability of the gas protection layer during the welding process.

[0017] The multi-layer concentric ring gas channels are integrated with adjustable-angle guide vanes, and the vanes can dynamically adjust the gas injection angle according to the welding position and the geometric dimensions of the narrow gap to ensure that the gas uniformly covers the molten pool and the weld area.

[0018] In the near-vertical narrow-gap welding process, the welding mechanism performs the welding process along the near-vertical direction. After completing a single-pass welding by layer-by-layer deposition of the wire, the wire quickly retracts to avoid adhesion to the solidified melt.

[0019] Subsequently, the welding mechanism advances a layer thickness along the welding direction to the starting point of the next welding track and performs a new round of near-vertical welding. This cycle continues until the full length of the workpiece is welded.

[0020] The adaptive clamping mechanism consists of multiple auxiliary support rods, and the auxiliary support rods are arranged in a preset spacing matrix on the support frame.

[0021] Each auxiliary support rod is inserted into the guide hole of the support frame. An elastic element is provided in the guide hole, and one end of the elastic element is connected to the pressing block of the auxiliary support rod, enabling the auxiliary support rod to perform adaptive displacement in the vertical direction under the action of the workpiece gravity.

[0022] The interior of the auxiliary support rod adopts a double-layer structure design. Among them, the inner layer is integrated with a vacuum suction cup, and the bottom of the vacuum suction cup is connected to a vacuum pressure pump through a pipeline to achieve negative pressure adsorption and fixation of the workpiece.

[0023] The outer layer forms a cooling gas channel. The cooling gas is supplied by a high-pressure gas cylinder and forms an atomized cooling protective gas after heat exchange through a water cooler, and is directionally diffused through the air holes on the auxiliary support rod to achieve local cooling of the workpiece and reduce the deformation of the welding heat-affected zone.

[0024] When the workpiece is placed on the adaptive clamping mechanism, the auxiliary support rods within the covered area of the workpiece move downward under the action of the workpiece gravity, and at the same time, the vacuum suction cup tightly adsorbs the bottom of the workpiece to provide rigid fixation.

[0025] The auxiliary support rods in the non-covered area remain in their initial positions, forming a support profile that matches the geometric shape of the workpiece, thereby restricting the degrees of freedom of the workpiece in the plane; when the workpiece is removed, the auxiliary support rods return to their initial positions under the reset force of the elastic elements.

[0026] The near-vertical narrow-gap welding joint is formed by superimposing multiple short welding tracks. The welding mechanism is precisely positioned in the vertical direction and performs layer-by-layer surfacing from the bottom to the top of the narrow gap, and reciprocates vertically in the narrow gap to achieve precise deposition of the welding wire.

[0027] During the first-layer welding process of near-vertical narrow-gap welding, the welding mechanism moves along the starting gasket in a track, stops depositing after completing a single-pass welding, the wire quickly retracts, then the welding mechanism advances a preset layer thickness along the welding direction and continues to perform welding deposition along the preset track. This cycle continues until the multi-layer welding operation of the entire narrow gap is completed.

[0028] A near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process, characterized by including the following steps:

[0029] Step 1: Place the workpiece to be welded on the adaptive clamping mechanism, ensure that the auxiliary support rods within the covered area of the workpiece automatically move downward under the action of gravity, and at the same time, the vacuum suction cup is activated to fix the bottom of the workpiece by negative pressure adsorption to ensure the stability of the workpiece during welding. The auxiliary support rods in the non-covered area remain in place, forming a support profile that matches the geometric shape of the workpiece and restricting the degrees of freedom of the workpiece in the plane.

[0030] Step 2: According to the characteristics of the welding material, configure the gas type and flow rate of the multi-layer concentric ring gas channels. Inert gas (such as argon) is introduced into the outer gas channel, and active gas or mixed gas is selected for the inner gas channel according to requirements. Adjust the adjustable-angle deflector blades to ensure that the gas injection angle matches the geometric dimensions of the narrow-gap groove, forming a uniform laminar protective gas curtain to cover the molten pool and weld area.

[0031] Step 3: Place an angle auxiliary metal block at one end of the narrow-gap groove on the surface of the workpiece to ensure a preset inclination angle is formed between the groove and the metal block to optimize the welding path. The welding mechanism performs the first-layer welding in the near-vertical direction through the coaxial wire feeding welding module. The welding wire is coaxially arranged with the laser beam, and wire deposition is performed along the preset track.

[0032] Step 4: After completing a single-pass welding, the wire quickly retracts to avoid sticking to the solidified melt. The welding mechanism advances a preset layer thickness along the welding direction and returns to the starting point of the next welding track. Repeat the above process and perform welding deposition layer by layer in the near-vertical direction until the multi-layer welding of the entire narrow gap is completed.

[0033] Step 5: During the welding process, atomized cooling gas is sprayed through the cooling air holes of the auxiliary support rod to locally cool the welding area and reduce thermal deformation. After welding is completed, the vacuum chuck is closed and the workpiece is removed. The auxiliary support rod returns to its initial position under the reset force of the elastic element, ready for clamping and welding of the next workpiece.

[0034] The present invention has the following beneficial effects:

[0035] 1. The present invention adopts a near-vertical narrow-gap laser welding method. By reciprocating the welding mechanism in the narrow gap along the near-vertical direction, an efficient and high-precision welding process is achieved. This method effectively solves the problems existing in traditional narrow-gap welding, such as uneven weld microstructure properties, complex operation, and low efficiency.

[0036] 2. The adaptive clamping mechanism automatically adapts to workpieces with different geometries through the dynamic adjustment of multiple auxiliary support rods. The vacuum chuck provides rigid fixation to ensure that the workpiece does not displace during the welding process. After welding is completed, the auxiliary support rod automatically resets under the action of the elastic element, significantly improving the clamping efficiency and being suitable for the rapid switching and continuous production of multi-variety and small-batch workpieces.

[0037] 3. The multi-layer concentric ring gas channels combined with adjustable-angle flow guiding vanes form a uniform laminar protective gas curtain. The outer layer uses inert gas to isolate the environment, and the inner layer selects active gas or mixed gas according to the characteristics of the welding material, significantly improving the protection effect of the welding area. The flow guiding vanes can dynamically adjust the gas spraying angle according to the welding position to ensure that the gas evenly covers the molten pool and the weld area, effectively preventing oxidation and impurity intrusion and improving the weld quality.

[0038] 4. The cooling air holes built in the auxiliary support rod can directionally spray atomized cooling gas to precisely control the local temperature of the welding area, significantly reducing the deformation of the welding heat-affected zone and ensuring the dimensional stability of the workpiece during the welding process, especially suitable for welding high-precision components sensitive to thermal deformation. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of a near-vertical narrow-gap laser welding device based on a coaxial wire feeding process;

[0040] Figure 2 It is a schematic diagram of the structure of the auxiliary support rod in the adaptive clamping mechanism;

[0041] Figure 3 It is a schematic diagram of the multi-layer concentric ring gas channels;

[0042] Figure 4 Welding trajectory;

[0043] Figure 5Schematic diagram of a near-vertical narrow-gap laser welding process;

[0044] Among them, 11 is a bracket; 12 is an adaptive clamping mechanism; 11 is a bracket; 12 is an adaptive clamping mechanism; 13 is an auxiliary support rod; 14 is a vacuum chuck; 15 is a cooling air hole; 16 is an elastic element; 17 is a pressure block; 18 is a vacuum pressure pump; 19 is a water chiller; 21 is a welding mechanism; 22 is a high-precision robotic arm; 23 is a coaxial wire feeding welding module; 24 is a gas channel; 25 is an inner gas channel; 26 is an outer gas channel; 27 is a guide vane; 31 is a workpiece; 32 is an angle auxiliary metal block; 33 is a protective gas cylinder; 41 is a welding track. Specific embodiments

[0045] To make the technical problems solved by the present invention, the technical solutions adopted, and the achieved technical effects clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present invention.

[0046] In the description of this embodiment, the orientation or positional relationship terms such as "upper", "lower", "left", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, 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.

[0047] The technical solutions of the present invention will be further described below with reference to the drawings and through specific embodiments.

[0048] The near-vertical narrow-gap laser welding device and method based on the coaxial wire feeding process includes a support frame 11, and an adaptive clamping mechanism 12 is arranged above the support frame.

[0049] The adaptive clamping mechanism 12 is composed of a plurality of auxiliary support rods 13.

[0050] The auxiliary support rod 13 can be dynamically adjusted in the vertical direction to automatically adapt to workpieces of different geometric shapes, ensuring high-precision positioning and stability of the workpiece 31 during the welding process.

[0051] The upper end of the auxiliary support rod 13 is integrated with a vacuum chuck 14, and the workpiece 31 is rigidly fixed through the vacuum adsorption force, effectively preventing displacement or thermal deformation during the welding process.

[0052] The auxiliary support rod 13 is internally provided with cooling air holes 15 for directionally spraying cooling gas to achieve local temperature control.

[0053] The surface of the workpiece 31 is machined with a narrow-gap groove, and an angular auxiliary metal block 32 is arranged at one end of the groove, and a preset inclination angle is formed between the metal block 32 and the groove.

[0054] A welding mechanism 21 is arranged above the workpiece 31, and the welding mechanism 21 works in cooperation with a high-precision robotic arm 22. The welding mechanism 21 includes a coaxial wire-feeding welding module 23, and the welding wire and the laser beam are coaxially arranged.

[0055] A multi-layer concentric ring gas channel 24 is arranged outside the coaxial wire-feeding welding module 23 to form a laminar flow protective gas curtain to achieve efficient isolation and protection of the welding area.

[0056] The gas channel 24 is composed of multiple independent gas layers. The outer gas 26 channel uses an inert gas for environmental isolation, and the inner gas 25 channel selects an active gas or a mixed gas according to the characteristics of the welding material to enhance the protection effect; the gas flow rates of the respective gas layers can be independently regulated to adapt to different welding process parameters and ensure the stability of the gas protection layer during the welding process.

[0057] Adjustable-angle guide vanes 27 are integrated in the multi-layer concentric ring gas channel 24, and the vanes 27 can dynamically adjust the gas injection angle according to the welding position and the geometric dimensions of the narrow gap to ensure that the gas uniformly covers the molten pool and the weld area.

[0058] In the near-vertical narrow-gap welding process, the welding mechanism 21 performs the welding process along the near-vertical direction. After completing a single-pass welding by layer-by-layer deposition of the wire, the wire quickly retracts to avoid adhesion to the solidified melt.

[0059] Subsequently, the welding mechanism advances one layer thickness along the welding direction to the starting point of the next welding track and performs a new round of near-vertical welding. This cycle continues until the full length of the workpiece is welded.

[0060] The auxiliary support rods 13 are arranged in a preset spacing matrix on the support frame 11.

[0061] Each auxiliary support rod 13 is inserted into the guide hole 111 of the support frame. An elastic element 16 is arranged in the guide hole 111, and one end of the elastic element 16 is connected to the pressing block 17 of the auxiliary support rod 13, enabling the auxiliary support rod 13 to perform adaptive displacement in the vertical direction under the action of the gravity of the workpiece 31.

[0062] The interior of the auxiliary support rod 13 is designed with a double-layer structure. Among them, a vacuum chuck 14 is integrated in the inner layer, and the bottom of the vacuum chuck is connected to a vacuum pressure pump 18 through a pipeline to achieve negative-pressure adsorption and fixation of the workpiece 31.

[0063] The outer layer forms a cooling gas channel. The cooling gas is supplied by a high-pressure gas cylinder 33 and undergoes heat exchange through a water cooler 19 to form an atomized cooling protective gas, which is directionally diffused through the air holes 15 on the auxiliary support rod 13 to achieve local cooling of the workpiece 31 and reduce the deformation of the welding heat-affected zone.

[0064] When the workpiece 31 is placed on the adaptive clamping mechanism 12, the auxiliary support rod 13 within the covered area of the workpiece moves downward under the action of the gravity of the workpiece 31. At the same time, the vacuum chuck 14 tightly adsorbs the bottom of the workpiece 31 to provide rigid fixation.

[0065] The auxiliary support rods 13 in the non-covered area remain in their initial positions to form a support profile matching the geometric shape of the workpiece 31, thereby restricting the degrees of freedom of the workpiece 31 in the plane. When the workpiece 31 is removed, the auxiliary support rods 13 return to their initial positions under the action of the restoring force of the elastic element 16.

[0066] The near-vertical narrow-gap welded joint is formed by superimposing multiple short-range welding tracks 41. The welding mechanism 21 reciprocates vertically within the narrow gap to achieve layer-by-layer deposition of the weld seam.

[0067] During the first-layer welding process of the near-vertical narrow-gap welding, the welding mechanism moves along the starting gasket 32 in a trajectory. After completing a single-pass welding, deposition stops, the wire quickly retracts, and then the welding mechanism 21 advances a preset layer thickness along the welding direction and continues to perform welding deposition along the preset trajectory. This cycle continues until the multi-layer welding operation of the entire narrow gap is completed.

[0068] A near-vertical narrow-gap laser welding device and method based on a coaxial wire feeding process, characterized by including the following steps:

[0069] Step 1: Place the workpiece 31 to be welded on the adaptive clamping mechanism 12 to ensure that the auxiliary support rod 13 within the covered area of the workpiece automatically moves downward under the action of gravity. At the same time, the vacuum chuck 14 is activated to fix the bottom of the workpiece 31 by negative pressure adsorption to ensure that the workpiece 31 remains stable during the welding process. The auxiliary support rods 13 in the non-covered area remain in place to form a support profile matching the geometric shape of the workpiece 31 and restrict the degrees of freedom of the workpiece 31 in the plane.

[0070] Step 2: According to the characteristics of the welding material, configure the gas type and flow rate of the multi-layer concentric ring gas channel 24. The outer layer 26 gas channel is filled with an inert gas (such as argon), and the inner layer 25 gas channel selects an active gas or a mixed gas according to requirements. Adjust the adjustable-angle guide vane 27 to ensure that the gas injection angle matches the geometric dimensions of the narrow-gap groove to form a uniform laminar protective gas curtain covering the molten pool and the weld area.

[0071] Step 3: Place the angle auxiliary metal block 32 at one end of the narrow-gap groove on the surface of the workpiece 31 to ensure a preset inclination angle is formed between the groove and the metal block 32, optimizing the welding path. The welding mechanism starts from the bottom of the narrow gap in a nearly vertical direction and performs the first-layer welding through the coaxial wire feeding welding module 23, depositing the wire along a preset trajectory.

[0072] Step 4: After completing a single-pass welding, the wire quickly retracts to avoid sticking to the solidified melt. The welding mechanism 21 advances a preset layer thickness in the welding direction to the starting point of the next welding trajectory. Repeat the above process and perform welding deposition layer by layer in a nearly vertical direction until the multi-layer welding of the entire narrow gap is completed.

[0073] Step 5: During the welding process, spray atomized cooling gas through the cooling air holes 15 of the auxiliary support rod 13 to locally cool the welding area and reduce thermal deformation. After welding is completed, turn off the vacuum chuck 14 and remove the workpiece 31. The auxiliary support rod 13 returns to its initial position under the restoring force of the elastic element 16, ready for clamping and welding of the next workpiece 31.

[0074] The present invention is further illustrated by a specific embodiment below.

[0075] The workpiece 31 is made of a 15 mm thick 316L stainless steel plate, processed into a rectangular groove with a width of 3 mm and a depth of 13 mm, and the filler wire is a stainless steel wire with a diameter of 1.2 mm.

[0076] The root of the groove is sealed by autogenous welding, and a -50° angle auxiliary metal block 32 is inserted into the narrow-gap groove to support the initial layer.

[0077] Further, place the workpiece 31 to be welded on the adaptive clamping mechanism 12 to ensure that the auxiliary support rod 13 within the covered area of the workpiece automatically moves downward under the action of gravity. At the same time, the vacuum chuck 14 is activated to fix the bottom of the workpiece 31 by negative pressure adsorption, ensuring that the workpiece 31 remains stable during welding. The auxiliary support rod 13 in the non-covered area remains in place, forming a support profile that matches the geometric shape of the workpiece 31, restricting the degrees of freedom of the workpiece 31 in the plane.

[0078] The laser used is a 15 kW fiber laser, the laser power is set to 3 kW, the welding speed is set to 0.02 m / s, the wire feeding speed is set to 20 mm / s, and the spot size is 4 mm (covering the width of the groove bottom).

[0079] Further, guide an alumina conduit (outer diameter 3.6 mm, inner diameter 1.6 mm) to the bottom of the groove, and set the wire retraction speed to 20 m / min and the retraction distance to 10 mm to prevent solidification adhesion.

[0080] Furthermore, CO2 gas is introduced into the inner layer of the multi-layer concentric ring gas channel, and the gas flow rate is set to 10 L / min. It can participate in the metallurgical reaction during welding, increase the penetration depth, and improve the welding efficiency. Ar is introduced into the outer layer, and the gas flow rate is set to 25 L / min to isolate the outside air and prevent the weld from oxidizing. Adjust the adjustable-angle deflector vane 27 to ensure that the gas injection angle matches the geometric dimensions of the narrow-gap groove, forming a uniform laminar protective gas curtain to cover the molten pool and the weld area.

[0081] Furthermore, start the welding mechanism to move to the bottom of the angle auxiliary metal block 32, and complete the first-layer welding along the angle auxiliary metal block through the coaxial wire feeding welding module 23. After welding is completed, the wire is retracted.

[0082] The interlayer cooling time is 6 s. After the interlayer cooling is completed, the welding mechanism 21 advances a preset layer thickness along the welding direction to the starting point of the next welding track, and repeats the above process according to the preset track to form 20 welds with a thickness of 12 mm, completing the welding of the entire narrow gap.

[0083] Furthermore, during the welding process, atomized cooling gas is sprayed through the cooling air holes 15 of the auxiliary support rod 13 to locally cool the welding area and reduce thermal deformation.

[0084] Furthermore, after welding is completed, turn off the vacuum chuck 14 and remove the workpiece 31. The auxiliary support rod 13 returns to its initial position under the restoring force of the elastic element 16, ready for the clamping and welding of the next workpiece 31.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A near vertical narrow gap laser welding device and method based on coaxial wire feeding process, characterized in that: It comprises a support frame, above which is arranged an adaptive clamping mechanism, the adaptive clamping mechanism being composed of a plurality of auxiliary support rods, the auxiliary support rods being dynamically adjusted in the vertical direction so as to automatically adapt to workpieces of different geometric shapes, thereby ensuring that the workpieces maintain high-precision positioning and stability during the welding process; a vacuum suction cup is integrated at the upper end of the auxiliary support rod, which realizes the rigid fixation of the workpiece by the vacuum adsorption force, thereby effectively preventing displacement or thermal deformation during the welding process; cooling air holes are arranged inside the auxiliary support rods for directional injection of cooling gas to realize local temperature control; a narrow gap groove is processed on the surface of the workpiece, and an angle auxiliary metal block is arranged at one end of the groove, and a preset inclination angle is formed between the metal block and the groove; a welding mechanism is arranged above the workpiece, and the welding mechanism works in coordination with a high-precision robotic arm, and the welding mechanism comprises a coaxial wire feeding welding module, in which the welding wire and the laser beam are coaxially arranged; the coaxial wire feeding welding A multi-layer concentric ring gas channel is arranged on the periphery of the module to form a laminar protective gas curtain to achieve efficient isolation and protection of the welding area; the gas channel is composed of multiple independent gas layers, the outer gas channel uses inert gas for environmental isolation, and the inner gas channel selects active gas or mixed gas according to the characteristics of the welding material to enhance the protection effect; the gas flow of each gas layer can be independently regulated to adapt to different welding process parameters and ensure the stability of the gas protection layer during welding; the multi-layer concentric ring gas channel is integrated with adjustable angle guide blades, which can dynamically adjust the gas injection angle according to the welding position and the geometric size of the narrow gap to ensure that the gas evenly covers the molten pool and the weld area; in the near-vertical narrow gap welding method, the welding mechanism performs welding operations in a near-vertical direction, and after completing a single-pass welding by near-vertical deposition of the metal wire, the metal wire quickly retracts to avoid adhesion with the solidified melt; Subsequently, the welding mechanism advances one layer thickness along the welding direction to the starting point of the next welding trajectory, and performs a new round of near-vertical welding, and repeats this cycle until the full-length welding of the workpiece is completed.

2. According to claim 1, a near-vertical narrow gap laser welding device and method based on coaxial wire feeding process is characterized in that: The adaptive clamping mechanism is composed of a plurality of auxiliary support rods, which are arranged on the support frame according to a preset spacing matrix; each auxiliary support rod is embedded in a guide hole of the support frame, and an elastic element is provided in the guide hole, and one end of the elastic element is connected to the pressure block of the auxiliary support rod, so that the auxiliary support rod can be adaptively displaced in the vertical direction under the action of the gravity of the workpiece; the interior of the auxiliary support rod adopts a double-layer structure design, in which the inner layer is integrated with a vacuum suction cup, and the bottom of the vacuum suction cup is connected to the vacuum pressure pump through a pipeline to achieve negative pressure adsorption and fixation of the workpiece; the outer layer constitutes a cooling gas channel, and the cooling gas is supplied by a high-pressure gas cylinder and passes through After heat exchange, the water cooler forms atomized cooling protective gas, which is directionally diffused through the pores on the auxiliary support rod to achieve local cooling of the workpiece and reduce deformation of the welding heat affected zone; when the workpiece is placed on the adaptive clamping mechanism, the auxiliary support rods in the workpiece coverage area move downward under the action of the workpiece's gravity, and at the same time the vacuum suction cup tightly adsorbs the bottom of the workpiece to provide rigid fixation; the auxiliary support rods in the non-covered area maintain their initial position, forming a support profile that matches the workpiece's geometric shape, thereby limiting the workpiece's degree of freedom in the plane; when the workpiece is removed, the auxiliary support rods return to their initial position under the action of the resetting force of the elastic element.

3. According to claim 1, a near vertical narrow gap laser welding device based on coaxial wire feeding process is characterized in that: The nearly vertical narrow gap welding joint is formed by superimposing multiple short-range welding trajectories, and the welding mechanism performs reciprocating motion in the vertical direction in the narrow gap; during the first layer welding process of the nearly vertical narrow gap welding, the welding mechanism moves along the trajectory of the starting gasket, and stops depositing after completing a single-pass welding, the metal wire quickly retracts, and then the welding mechanism advances a preset layer thickness along the welding direction, and continues to perform welding deposition along the preset trajectory, and this cycle is repeated until the entire narrow gap multi-layer welding operation is completed.

4. A near vertical narrow gap laser welding device and method based on coaxial wire feeding process, characterized in that: The following steps are involved: Step 1: Place the workpiece to be welded on the adaptive clamping mechanism, ensure that the auxiliary support rods in the workpiece coverage area automatically move down under the action of gravity, and at the same time, the vacuum suction cup is activated to fix the bottom of the workpiece through negative pressure adsorption to ensure that the workpiece remains stable during the welding process. The auxiliary support rods in the uncovered area remain in place to form a support profile that matches the workpiece geometry and limits the workpiece's freedom in the plane. Step 2: According to the characteristics of the welding material, configure the gas type and flow rate of the multi-layer concentric ring gas channel. The outer gas channel is fed with inert gas (such as argon), and the inner gas channel is selected with active gas or mixed gas according to the needs. Adjust the adjustable angle guide vane to ensure that the gas injection angle matches the geometric dimensions of the narrow gap groove to form a uniform laminar protective gas curtain covering the molten pool and weld area. Step 3: Place an angled auxiliary metal block at one end of the narrow gap groove on the workpiece surface to ensure a preset tilt angle between the groove and the metal block to optimize the welding path. The welding mechanism starts from the bottom of the narrow gap in a nearly vertical direction and performs the first layer welding through the coaxial wire feeding welding module. The welding wire is coaxially arranged with the laser beam, and the metal wire is deposited along the preset trajectory. Step 4: After completing a single pass of welding, the wire quickly retracts to avoid sticking to the solidified melt. The welding mechanism advances a preset layer thickness in the welding direction and returns to the starting point of the next welding track. Repeat the above process, welding deposition layer by layer in a nearly vertical direction until the multi-layer welding of the entire narrow gap is completed. Step 5: During welding, atomized cooling gas is sprayed through the cooling holes of the auxiliary support rod to locally cool the welding area and reduce thermal deformation. After welding is completed, the vacuum suction cup is closed and the workpiece is removed. The auxiliary support rod returns to its initial position under the reset force of the elastic element, ready for clamping and welding of the next workpiece.

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