A device for controlling the gas flow during laser welding, fixed in the nozzle of a manual laser welding head

Abstract

This utility model relates to arc welding, specifically to auxiliary devices for electrodes. The device for controlling the gas flow during laser welding, mounted in the nozzle of a handheld laser welding head, comprises a laminar gas lens with a laminar gas diffuser, a quick-release fitting, and a bracket. The gas lens has a cylindrical housing, within which the laminar gas diffuser is secured.A quick-release process gas supply fitting is installed in the housing. The housing is designed to supply process gas to the welding zone and is secured in a bracket consisting of two parts: the first part of the bracket is cylindrical, matches the diameter of the housing, and serves as a clamping element. A through-threaded hole is made in the upper part of the first part of the bracket. The second part of the bracket is located above the housing at an angle to the central axis of the gas lens and contains an opening for attaching the welding wire feed cable channel to the welding gun nozzle. An adapter for the laser beam is located inside the laminar gas diffuser. The laminar gas diffuser is stepped and consists of four removable and replaceable meshes. The first mesh is located on the side of the quick-release process gas supply fitting and is made of solid metal 0.7-1 mm thick with perforations forming holes 1.4-1.7 mm in diameter.The second mesh is made of metal thread with a mesh size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm. The third mesh is made of metal thread with a mesh size of 0.9-1.1 mm and a wire diameter of 0.3-0.4 mm. The fourth mesh is made of metal thread with a mesh size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm. The technical result consists in reducing the formation of metal spatter in the weld zone. 1 c.p. fil., 1 fig.

Description

[0001] The utility model relates to arc welding and discloses auxiliary devices for electrodes [B23K9 / 00, B23K9 / 28].

[0002] A gas-arc welding torch with a built-in vision sensor is known from the prior art [US4521670A, published 04.06.1985]. The gas-arc welding torch has a built-in optical system that projects a weld pool onto the surface of a fiber optic cable. A concentric torch configuration is presented with a thin filler wire guide, which is detachably mounted on the annular torch body and protrudes into the gas cup at an angle to the optical axis in order to minimize the overlap of important areas of the welding zone. The fiber optic cable is connected to a video camera and a viewing system or controller; real-time monitoring of the welding zone is carried out, which is used to control the welding process.

[0003] The disadvantage of the analogue is that it describes the gas lens only as a “permeable barrier of alternating layers of fine metal mesh” designed to increase the range of effective gas coverage, but does not disclose such a set of design features as a specific multi-stage configuration of meshes with specified sizes of holes and cells, their location relative to the inlet fitting and the ability to select and replace a set of meshes, ensuring a laminar flow specifically for the purpose of suppressing splashes of the weld pool and reducing the formation of metal spatter.In addition, the analogue lacks a bracket with a clamping cylindrical first part, matched with the lens body, and an inclined second part with holes for the organized fastening of supply communications, which does not allow for a comparable level of spatial stabilization of the position of the gas lens and cable channel relative to the welding zone and, therefore, does not sufficiently eliminate fluctuations in the direction and structure of the gas flow, leading to the continued increased formation of metal spatter in the weld zone.

[0004] A MANUAL LASER WELDING UNIT is known from the prior art [US2006175308A1, published 10.08.2006]. A manual laser fusion welding unit intended for processing a workpiece, including: a main body, the dimensions of which allow it to be held in a hand and which is adapted for connection with at least a laser radiation system; a nozzle connected to the main body and having an opening through which laser light from the laser radiation system can pass; and a gas lens connected to the main body and surrounding at least a part of the nozzle, intended to receive a flow of inert gas from an inert gas supply system.

[0005] A drawback of the analog is that it describes the gas lens only as a unit surrounding the nozzle and receiving the inert gas flow, without revealing the multi-stage laminar diffuser with specific mesh parameters and their arrangement, which allows for the targeted reduction of flow turbulence and, consequently, metal spatter formation in the weld zone. Furthermore, the analog lacks a bracket design with a clamping cylindrical part matched to the lens body and an inclined second part with holes for organized cable channel attachment. This does not provide comparable spatial stabilization of the gas lens and feed lines relative to the welding zone and does not sufficiently eliminate fluctuations in the direction and structure of the gas flow, which lead to persistent increased metal spatter.

[0006] The closest in technical essence is the GAS LENS ASSEMBLY FOR A WELDING TORCH [US5772102A, published 30.06.1998]. A gas lens for an arc welding torch includes a lens housing with rear and front ends, a passage through the lens housing from the front end to the rear end for feeding an electrode and passing an inert gas in a forward direction in the passage. The lens housing is attached to the lens housing and defines a chamber around the front of the lens housing. One or more openings in the front of the lens housing allow inert gas to flow from the passage into the chamber. The gas lens assembly further includes a flow control device associated with the housing, through which the inert gas is adapted to move forward. The flow control device controls the flow of inert gas therethrough, so that the flow control device is in the form of a laminar flow of forward-moving gas. The laminar flow is adapted to cover the welding puddle during welding of the workpiece.The gas lens assembly further includes a flow control device holder that easily and seamlessly connects to the lens housing, allowing the flow control element to be easily replaced.

[0007] A disadvantage of the prototype is that its gas lens is implemented as a flow control device, ensuring a laminar flow of inert gas to the weld pool. However, the combination of features of a multi-stage diffuser with specifically defined mesh parameters and their arrangement, which would allow for the targeted reduction of flow turbulence to reduce metal spatter in the weld zone, is not disclosed. Furthermore, the prototype lacks a bracket with a clamping cylindrical portion aligned with the lens housing and an inclined second portion with an opening for the organized attachment of a cable channel. This, in the claimed utility model, achieves additional spatial stabilization of the gas lens and the supplied communications relative to the weld zone, reducing fluctuations in the direction and structure of the gas flow and, consequently, the formation of metal spatter.

[0008] The objective of the utility model is to improve the design of a gas lens.

[0009] The technical result achieved in the utility model is a reduction in the formation of metal spatter in the weld zone.

[0010] This technical result is achieved due to the fact that the device for controlling the gas flow during laser welding, fixed in the nozzle of a manual laser welding head, containing a laminar gas lens with a laminar gas diffuser, a quick-release fitting and a bracket, wherein the gas lens has a cylindrical housing, inside which a laminar gas diffuser is fixed, a quick-release fitting for supplying process gas is installed in the housing, the housing is configured to supply process gas to the welding zone and is fixed in a bracket consisting of two parts: the first part of the bracket is made cylindrical, corresponds to the diameter of the housing and is a clamping one, in the upper part of the first part of the bracket a through threaded hole is made, the second part of the bracket is located above the housing at an angle to the central axis of the gas lens and contains an opening for attaching a cable channel for feeding welding wire to the nozzle of the welding gun,an adapter for a laser beam is placed inside the laminar gas diffuser, wherein the laminar gas diffuser is made stepped and consists of four grids made with the possibility of removal and replacement, the first grid is located on the side of the quick-release fitting for supplying process gas, is made of solid metal with a thickness of 0.7-1 mm with perforation forming holes with a diameter of 1.4-1.7 mm, the second grid is made of a metal thread with a cell size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm, the third grid is made of a metal thread with a cell size of 0.9-1.1 mm and a wire diameter of 0.3-0.4 mm, the fourth grid is made of a metal thread with a cell size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm.,

[0011] In particular, the laminar gas diffuser meshes are made of heat-resistant steel.

[0012] The essence of the utility model is explained by drawings

[0013] Fig. 1 shows the general appearance of the lens.

[0014] The figure shows: 1 - body, 2 - diffuser, 3 - mesh, 4 - bracket, 5 - first part, 6 - hole, 7 - second part, 8 - adapter, 9 - hole, 10 - fitting, 11 - nozzle, 12 - central axis.

[0015] The supply of inert process gas in traditional welding systems (TIG, MIG / MAG) and manual laser welding solves the following problems: cooling the welding zone, displacing atmospheric oxygen to prevent oxidation of the melt and partial formation of the leg and other parameters of the shape and geometry of the weld.

[0016] To solve these problems, a laminar gas lens for manual laser welding systems (Fig. 1) was created, which is a pneumatic aerodynamic device for controlling the gas flow and forming its structure.

[0017] Structurally, the lens consists of a cylindrical housing 1 of an experimentally selected volume with aerodynamically perfect internal surfaces, mechanically attached to the gap of the existing standard nozzle of a manual laser welding head.

[0018] A stainless steel laminar gas diffuser 2 is mounted inside this housing 1 to form a structured laminar gas flow of the required volume. Gas diffuser 2 consists of 2-4 meshes 3, with the meshes of diffuser 2 being perforated. Preferably, a set of meshes consists of one main mesh made of solid metal, 0.7-1 mm thick and with a perforation diameter of 1.4-1.7 mm. This mesh is located closer to the quick-release fitting 10 for gas supply. Next, there is preferably a mesh made of metal thread with a cell size of 0.3-0.5 mm, and a wire diameter of 0.2-0.3 mm. After it, a larger mesh with a cell size of 0.9-1.1 mm and a wire diameter of 0.3-0.4 mm is installed. The final mesh is made of metal thread with a mesh size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm. These meshes are preferably made of heat-resistant AISI 304 (08X18H10) steel.

[0019] During operation, the operator of the manual laser welding machine can independently change the composition of the meshes 3 in the diffuser 2, thereby generating different gas flows. An adapter 8 for feeding the laser beam is located inside the diffuser 2.

[0020] The said body 1 is secured in a bracket 4, the first part 5 of which is made cylindrical and corresponds to the diameter of the body 1. The first part 5 of the bracket 4 is made clamping, to ensure the possibility of removing and putting the bracket on the body 1, and its upper part ends with a through hole 6 with a thread to ensure the possibility of clamping the body 1 in the bracket 4. The second part 7 of the bracket 4 is made above the body 1 and is mounted at an angle to the central axis 12 of the gas lens, in it an opening 9 is made for fastening the cable channel for feeding the welding wire to the nozzle of the welding gun.

[0021] At the rear part of the housing 1, a quick-release fitting 10 is provided for supplying process gas to the housing 1.

[0022] The body 1 is connected to the nozzle 11, which is designed to supply gas.

[0023] This lens achieves the following technical results. The formation of carbon and oxide deposits in the weld zone is significantly reduced, sparking is significantly reduced in the laser beam and weld pool, metal spatter is significantly reduced in the weld zone, weld zone overheating and the formation of "temper color" on stainless steel are reduced, workpiece cooling is improved, and assembly warpage is reduced due to a smaller heat-affected zone. The structure and shape of the weld root (back bead) is significantly improved when welding thicknesses typical for manual laser welding systems, and the stability and repeatability of the achieved welding results are also achieved.

[0024] The laminar gas lens comprises a cylindrical housing containing a laminar gas diffuser. A quick-release fitting is installed at the rear of the housing, and the housing is connected to a nozzle for supplying process gas to the welding zone. The cylindrical housing ensures axisymmetric flow of shielding gas and the formation of a stable, near-laminar gas flow around the weld pool. This reduces turbulent disturbances and, consequently, air infiltration, which leads to increased metal spatter formation. The presence of a gas diffuser, which determines the flow structure, ensures equalization of the gas velocity distribution across the cross-section and a more laminar flow, improving the weld pool's protection from air, stabilizing the thermal regime, and reducing metal spatter formation in the near-weld zone.The quick-release fitting ensures a leak-proof and technologically stable connection of the gas supply hose to the housing, reducing leaks and gas flow fluctuations. This results in a more stable gas shielding mode, reducing fluctuations in metal melting conditions and helping to reduce spatter formation. The rigid connection between the housing and the nozzle ensures a fixed gas supply path and a consistent position of the gas lens relative to the weld pool, reducing misalignment and gas flow drift, reducing air leakage, and stabilizing the weld pool, thereby reducing metal spatter.

[0025] The housing is secured in a bracket, increasing the mechanical rigidity of the assembly and reducing vibration and lens displacement relative to the welding point when moving the welding gun. This reduces fluctuations in the gas stream direction and, consequently, fluctuations in the gas shield and the formation of metal spatter in the weld zone. The first part of the bracket is cylindrical and matches the diameter of the housing. The first part of the bracket serves as a clamping element, with a through-threaded hole in its upper portion. Matching the geometry of the first part of the bracket with the housing diameter ensures a tight grip and uniform distribution of the clamping force, preventing housing distortion and maintaining the alignment of the gas lens and nozzle. This reduces the likelihood of uneven airflow across the weld pool, which leads to localized oxidation and increased spatter.The clamping design with a threaded hole allows the housing to be securely fixed in a given position and its orientation to be quickly adjusted. This ensures a constant direction of the gas flow relative to the weld, reduces random displacements and, as a result, reduces fluctuations in gas protection and the amount of metal spatter.

[0026] The second bracket section is positioned above the housing at an angle to the central axis of the gas lens and contains an opening. This placement of the second section ensures that the fasteners and cable duct are positioned away from the main gas flow, reducing aerodynamic interference and jet disruption. This helps maintain a laminar airflow around the welding zone and minimizes the risk of turbulent air intake and metal spatter. The opening in the second section provides a designated location for securing additional utilities, preventing the cable and hose system from being positioned or swaying near the gas flow zone. This reduces accidental blockages and flow disruptions, thereby reducing gas shield fluctuations and metal spatter.A laser beam adapter is located inside the laminar gas diffuser, which ensures the passage of the laser beam in a given position inside the diffuser, setting the coaxiality of the beam focus and the gas flow, which stabilizes the shape and position of the weld pool and reduces local overheating and splashes of melt, leading to metal spatter in the weld zone.

[0027] The laminar gas diffuser consists of a set of 2-4 meshes, secured in a housing that can be disassembled and replaced. Using multiple meshes allows for gradual equalization of gas velocity across the cross-section, breaking up large-scale vortices, and creating a more uniform laminar flow, which reduces the turbulent effect of gas on the weld pool and minimizes metal spatter. The ability to disassemble and replace the meshes allows the operator to tailor the flow pattern to the specific welding mode and material properties, minimizing spatter formation by optimizing gas shielding.

[0028] At least one of the meshes is made of solid metal 0.7-1 mm thick with perforations forming holes 1.4-1.7 mm in diameter. The perforated metal mesh is located closer to the quick-release fitting for supplying the process gas. The perforated solid metal mesh of a specified thickness and hole diameter evens out the flow velocity profile already at the diffuser inlet and dampens large-scale disturbances, creating a more uniform flow in front of subsequent meshes. This reduces turbulence and ensures stable gas coverage of the weld pool, reducing metal spatter.

[0029] At least one of the meshes in the kit is made of metal thread with a mesh size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm. This fine-mesh mesh creates a significant number of small channels, further laminating the flow and smoothing out any remaining irregularities after the perforated sheet. A more uniform and gentle gas flow reduces localized pressure fluctuations on the weld pool surface and decreases the likelihood of molten droplet ejection, thereby reducing the formation of metal spatter in the weld-affected zone.

[0030] At least one of the meshes in the kit is made of metal thread with a mesh size of 0.9-1.1 mm and a wire diameter of 0.3-0.4 mm. The larger mesh acts as an intermediate stage between the perforated sheet and the fine mesh, providing flow redistribution and reducing pressure drop, which reduces the risk of secondary turbulence behind the fine mesh. This maintains a stable gas shield and further reduces metal spatter.

[0031] The laminar gas diffuser meshes are made of heat-resistant steel. Heat-resistant steel maintains the mesh geometry, including mesh size, wire thickness, and hole shape, even when exposed to high temperatures and hot gas, ensuring consistent diffuser performance over time. Stable channel geometry maintains a consistent gas flow structure, ensuring stable weld pool protection and long-term reduction of metal spatter in the weld-affected zone.

[0032] The bracket opening is designed to secure the welding wire feed conduit to the welding gun nozzle. This functional conduit mounting hole allows the wire feed conduit to be firmly secured to the nozzle and gas lens, preventing vibration and accidental gas flow interruptions. This prevents localized jet interruptions, air leaks, and brief interruptions in gas shielding. This, in turn, reduces weld pool splashes and increased spatter formation in the weld zone, ensuring the specified technical result.

[0033] During the implementation of a gas lens in accordance with the description of the claimed object, it was possible to reduce metal spatter in the weld zone by 14%. For this purpose, under identical welding conditions (material, thickness, current, speed, gas, filler), a series of welds were performed without a gas lens and with the claimed lens. The surface around the weld was then cleaned and the area and intensity of spatter were assessed using photographs. The tests used a gas lens with various mesh sets, as shown in the implementation variants below.

[0034] IMPLEMENTATION EXAMPLES

[0035] In one embodiment, the laminar gas diffuser contained two meshes: the first mesh, made of solid 0.9 mm thick metal with perforations creating 1.5 mm diameter holes and located closer to the quick-release process gas supply fitting, and the second mesh, made of metal thread with a mesh size of 0.3 mm and a wire diameter of 0.2 mm. This sequence ensures preliminary alignment of the flow velocity profile by the perforated mesh and additional laminarization by the fine-mesh mesh.

[0036] In another embodiment, the diffuser contained three meshes: the first was a 0.7 mm thick perforated metal mesh with 1.4 mm diameter holes; the second mesh was made of metal thread with a 1 mm mesh size and a 0.3 mm wire diameter; and the third mesh was made of metal thread with a 0.3 mm mesh size and a 0.3 mm wire diameter. The perforated mesh was located on the side of the quick-release fitting, the mesh with a larger mesh size was located downstream of it, and the fine mesh was located at the diffuser outlet. This configuration ensures the gradual suppression of large-scale vortices, flow redistribution, and the final formation of a laminar gas flow at the outlet.

[0037] In another embodiment, the diffuser contains four meshes. The first and third meshes are made of metal thread with a 0.5 mm mesh size and a 0.3 mm wire diameter. The second mesh is made of metal thread with a 1.1 mm mesh size and a 0.4 mm wire diameter. The fourth mesh is made of solid 0.8 mm thick metal with perforations and holes of 1.6 mm diameter and is located closer to the quick-release fitting. This alternation of perforated and wire meshes with different mesh sizes allows for different pressure and gas velocity profiles, allowing for the flow structure to be adapted to specific welding conditions.

[0038] This utility model is a laminar gas lens design for manual laser welding. The combination of a multi-stage mesh diffuser and a stabilizing bracket ensures the formation of a stable laminar shielding gas flow and spatial stabilization of the gas lens and supply lines relative to the welding zone. This reduces gas flow turbulence, minimizes air leakage into the weld pool, and minimizes fluctuations in metal melting conditions. This reduces the formation of metal spatter in the weld zone compared to known solutions using gas lenses without this combination of design features.

Claims

1. A device for controlling a gas flow during laser welding, fixed in the nozzle of a hand-held laser welding head, containing a laminar gas lens with a laminar gas diffuser, a quick-release fitting and a bracket, wherein the gas lens has a cylindrical housing, inside which a laminar gas diffuser is fixed, a quick-release fitting for supplying process gas is installed in the housing, the housing is configured to supply process gas to the welding zone and is fixed in a bracket consisting of two parts: the first part of the bracket is made cylindrical, corresponds to the diameter of the housing and is a clamping one, in the upper part of the first part of the bracket a through threaded hole is made, the second part of the bracket is located above the housing at an angle to the central axis of the gas lens and contains an opening for attaching a cable channel for feeding welding wire to the nozzle of the welding gun, an adapter for the laser beam is located inside the laminar gas diffuser,wherein the laminar gas diffuser is made stepped and consists of four meshes, made with the possibility of removal and replacement, the first mesh is located on the side of the quick-release fitting for supplying process gas, is made of solid metal with a thickness of 0.7-1 mm with perforation forming holes with a diameter of 1.4-1.7 mm, the second mesh is made of metal thread with a cell size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm, the third mesh is made of metal thread with a cell size of 0.9-1.1 mm and a wire diameter of 0.3-0.4 mm, the fourth mesh is made of metal thread with a cell size of 0.3-0.5 mm and a wire diameter of 0.2-0.3 mm., 2. The device according to paragraph 1, characterized in that the meshes of the laminar gas diffuser are made of heat-resistant steel.

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