A gas blowing pipe for laser welding

Abstract

The application relates to a laser welding air blowing pipe for automobile door ring seams, which comprises a second pipe provided with a second air outlet on the outer surface; a first pipe with one end closed and the other end connected with an air source, and an annular gap formed between the two pipes, and the pipe wall of the first pipe is provided with a first air outlet; and the second air outlet is opposite to the seam during use. The air blowing pipe makes the protective gas enter from the first air outlet and uniformly guide through the annular gap, and is directionally sprayed from the second air outlet opposite to the seam, so that the air can be sent upward from the lower side of the door ring, the downward infiltration of the molten metal caused by the air supply on the upper side is effectively inhibited, the welding area coverage and stability are improved, the oxidation resistance is enhanced, and the weld forming and the controllability of the excess height are improved.

Description

Technical Field

[0001] This utility model relates to air blowing pipes, and more particularly to an air blowing pipe for laser welding. Background Technology

[0002] Automotive door rings are typically assembled from multiple sheet metal pieces sequentially along their circumference, forming narrow, long seams between adjacent pieces. To achieve high-quality connections and reduce the heat-affected zone, OEMs commonly use laser welding for continuous welding of these seams. Laser welding is sensitive to the atmosphere in the welding area. To suppress oxidation and improve the stability of the weld metal and the formed metal, a shielding gas supply system is often installed at the welding station on the production line, ensuring that the shielding gas flow covers the welding point along the seam direction.

[0003] In existing production lines, the air supply pipe is usually positioned on the same side as the laser welding gun (typically the upper side of the component to be welded), and the blown protective gas covers the joint from top to bottom. This type of upper-side air supply structure generally exits through the end of the pipe, making installation simple.

[0004] However, in actual welding processes, the molten metal and welding wire, under the combined influence of gravity and the airflow from above, tend to seep downwards through the joint and cool and solidify on the underside of the door ring, resulting in a relatively large "residual height" on the lower surface. Therefore, there is an urgent need to propose an air blowing pipe suitable for placement on the underside of the door ring to solve the above problem. Utility Model Content

[0005] The purpose of this invention is to provide a laser welding air pipe suitable for installation on a door ring, which enables the directional air outlet located on the outside to stably face and align with the seam during use.

[0006] The technical solution adopted by this utility model to solve the above problems is: a laser welding air pipe, suitable for welding the seams of automotive door ring splices, comprising: The second fitting has a second air outlet on its pipe wall that communicates with the outer surface; The first pipe is inserted inside the second pipe, and an annular gap is formed between the first pipe and the second pipe. A first air outlet communicating with the outer surface is opened on the pipe wall of the first pipe. One end of the first pipe is closed, and the other end is used to communicate with a gas source supplying protective gas.

[0007] The second air outlet is configured to face and be directly opposite the seam of the door ring splice when in use.

[0008] Preferably, the first air outlet and the second air outlet are arranged alternately in the circumferential direction.

[0009] Preferably, the air blowing pipe further includes a sealing ring disposed in the annular gap between the first pipe and the second pipe to seal the annular gap, so that the protective gas entering the annular gap from the first air outlet is ejected only through the second air outlet.

[0010] Preferably, the first pipe fitting and the second pipe fitting are coaxially arranged.

[0011] Preferably, the second air outlet is a narrow slit, the long axis of which is parallel to the axis of the second pipe and is continuously opened along the generatrix direction of the second pipe.

[0012] Preferably, the orifice shape of the first air outlet is any one of a slit, a round hole, a square hole, or an irregularly shaped hole.

[0013] Preferably, there are two sealing rings, which are located on both sides of the first air outlet and the second air outlet along the axial direction of the first pipe, respectively, so as to form an air supply chamber through the outer surface of the first pipe, the inner wall of the second pipe, and the opposite sides of the two sealing rings.

[0014] Preferably, the air blowing pipe further includes an adjusting pipe, which is sleeved on the outside of the second pipe and can move along the axial direction of the second pipe. The adjusting pipe is used to partially block the second air outlet to adjust the effective opening length of the second air outlet.

[0015] Preferably, a filler is provided between the inner wall of the regulating tube and the outer surface of the second pipe fitting to seal the gap between them.

[0016] Preferably, the first air outlet is configured as at least one along the axial direction of the first pipe, and forms a connecting air passage with the second air outlet, consisting of the first air outlet, the annular gap, and the second air outlet.

[0017] Beneficial effects of the embodiments of this utility model 1. Due to the adoption of a technique in which the first pipe is inserted into the second pipe and connected to the air source, forming an annular gap between the two as an air supply channel, and the first pipe has a first air outlet on its wall, and the second pipe has a second air outlet on its wall that is connected to the outer surface and is directly opposite the joint during use, the protective gas is uniformly guided from the inside to the outside through the annular gap and directionally ejected from the outlet directly opposite the joint. The air blowing pipe can be arranged on the lower side of the gate ring to deliver air upwards, which effectively solves the problems of molten metal seeping down and excessive residual height on the lower side of the gate ring caused by upper air supply in the existing technology. At the same time, it improves the coverage and stability of the protective airflow to the welding area, thereby achieving the technical effects of improved oxidation resistance of the welding area, more stable weld formation, and controlled residual height.

[0018] 2. By employing a technique where the first and second air outlets are staggered around the circumference of the pipe fitting, the molten metal and spatter falling along the direction of gravity do not directly align with the first air outlet on the gas supply side. This avoids blockage of the first air outlet and the resulting backflow and pressure fluctuations. It also prevents the gas in the annular gap from directly passing through the inner and outer air outlets, thus avoiding gas short-circuiting and jet interference. This effectively solves the technical problems of easy blockage of the lower gas supply, unstable protective airflow, and difficulty in continuously supplying gas to the joint in the prior art. As a result, it achieves stable, directional, and continuous coverage of the welding area by the protective gas, improves oxidation resistance and forming stability, and helps to suppress molten metal seepage, reduce the excess height on the lower side of the door ring, and reduce maintenance frequency. Attached Figure Description

[0019] Figure 1 A schematic structural diagram of an air blowing tube according to an embodiment of the present invention is shown.

[0020] Figure 2 A schematic front sectional view of the air blowing pipe according to an embodiment of the present invention is shown.

[0021] Figure 3 An explosion view of the air blowing pipe proposed in an embodiment of this utility model is shown. Figure 1 .

[0022] Figure 4 An explosion view of the air blowing pipe proposed in an embodiment of this utility model is shown. Figure 2 .

[0023] Wherein: 10, regulating pipe; 20, second fitting; 210, second air outlet; 30, first fitting; 310, first air outlet. Detailed Implementation

[0024] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0025] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] Please see Figures 1 to 4 A preferred embodiment of this application provides a laser welding air pipe suitable for welding the seams of automotive door ring splices, comprising a second pipe 20 and a first pipe 30. The second pipe 20 has a second air outlet 210 communicating with its outer surface on its wall. The first pipe 30 is inserted inside the second pipe 20, and the first pipe 30 and the second pipe 20 are coaxially arranged, forming an annular gap between them. The first pipe 30 has a first air outlet 310 communicating with its outer surface on its wall, one end of the first pipe 30 is closed, and the other end is used to communicate with a gas source supplying protective gas. The second air outlet 210 is configured to face and directly confront the seam of the door ring splice in use. At least one first air outlet 310 is provided along the axial direction of the first pipe 30, and a communicating air path is formed between the first air outlet 310, the annular gap, and the second air outlet 210.

[0028] Specifically: The second tube 20 is a hollow tubular body with a second air outlet 210 on its wall that communicates with its outer surface. The second air outlet 210 is preferably a narrow slit extending along the generatrix of the tube to form a linear air curtain. The first tube 30 is inserted inside the second tube 20 and coaxially arranged therewith. Coaxiality is ensured between the two through form and positional fit and tolerance matching, thus forming a continuous annular gap between them. The first tube 30 is a hollow tubular structure with a first air outlet 310 on its wall that communicates with its outer surface. One end of the first tube 30 is closed, and the other end is provided with an air supply interface for communication with an external protective gas source. In use, the second air outlet 210 is positioned facing and directly opposite the seam of the door ring splice. The first air outlet 310 and the second air outlet 210 correspond to each other axially, allowing the airflow entering the annular gap from the first air outlet 310 to be guided through the connecting air passage and ejected from the second air outlet 210. Both fittings can be made of high-temperature resistant, oxidation-resistant metal materials or high-temperature resistant engineering materials with matching thermal conductivity and strength. The first air outlet 310 and the second air outlet 210 can be achieved through machining, laser cutting, or forming and grooving. The edges of the air outlets are preferably blunted or polished to reduce flow separation. To improve stability, the outer surface of the first fitting 30 and the inner wall of the second fitting 20 can be precision machined or surface densified to reduce the friction resistance along the annular gap and improve the uniformity of air supply.

[0029] During operation, protective gas enters the inner cavity of the first fitting 30 through the gas supply interface from the gas source. After passing through the first outlet 310 and entering the annular gap, it spreads circumferentially and axially, achieving initial homogenization of pressure and flow. Subsequently, the gas is directionally ejected from the second outlet 210, directly opposite the joint, via the connecting gas path corresponding to the joint position, forming a stable protective gas curtain on the joint surface. As the welding heat source moves along the joint, the gas blowing pipe can remain relatively fixed with the welding fixture or move synchronously, ensuring continuous coverage of the welding area by the protective gas curtain. During start-up and shutdown, the gas supply can be stabilized first, and then welding can be started; at the end, the welding heat source can be turned off first, and then the gas supply can be gradually stopped to avoid hot oxidation and spatter re-attachment.

[0030] It should be noted that during the assembly stage, the coaxiality of the two pipe fittings should be corrected to ensure that the annular gap is continuous and without obvious step changes. The position and opening form of the first air outlet 310 should correspond axially with that of the second air outlet 210 to shorten the gas flow path from the inside to the outside and reduce dynamic pressure loss. Before use, check whether the first air outlet 310 and the second air outlet 210 are clean and unobstructed. After ventilation, observe the continuity and adhesion of the air curtain at the second air outlet 210. If necessary, adjust the posture of the relative joints of the blowing pipes to achieve precise alignment of the spray direction. During operation, pay attention to the stability of the air supply pressure to avoid intermittent or offset air curtain due to fluctuations.

[0031] This air blowing tube is suitable for common working conditions in laser welding stations, including high-temperature radiation, metal spatter, and dust environments. It is preferably used in stations with reliable exhaust ventilation and protective shielding, and should be installed in conjunction with existing welding fixtures or robot end effectors. The protective gas can be inert or weakly reactive, and the supply pressure and flow rate are set according to process parameters such as welding speed, material type, and plate thickness. The outer surface of the device can be treated with heat-resistant or anti-adhesion coatings as needed to reduce the impact of spatter adhesion on the edge of the air outlet.

[0032] In some optional embodiments, the second air outlet 210 can be a continuous slit or a quasi-continuous structure formed by splicing multiple slits, or it can be set as a segmented opening according to the splice length; the first air outlet 310 can be a slit, circular, or polygonal hole, and can be arranged as a single point or multiple points along the axial direction of the first pipe 30 to adapt to the air passage requirements at different locations. The cross-sections of the two pipes can be circular or nearly circular, or they can be elliptical or polygonal to match the installation space. The closed end of the first pipe 30 can be located at the end away from the air supply interface, and the air supply interface can be quickly connected to the existing air supply soft and hard pipes; without changing the definition of the claims, the pressure drop distribution and spray uniformity in the annular gap can be optimized by adjusting the relative distance and coverage of the first air outlet 310 and the second air outlet 210 in the axial direction.

[0033] In this embodiment, due to the adoption of the technical means of inserting the first pipe 30 and connecting it with the gas source, forming an annular gap with the second pipe 20, and opening corresponding first air outlets 310 and second air outlets 210 facing the joint on the pipe walls of the first pipe 30 and the second pipe 20 respectively, the protective gas can be uniformly guided from the inside to the outside through the connecting gas path and directionally sprayed out at the joint. This effectively solves the technical problems in the prior art where the protective airflow is difficult to stably adhere and cover the target area and is easily deviated by the position of the work station. Thus, the technical effects of continuous and stable protective air curtain, improved anti-oxidation ability, and more uniform and controllable weld formation are achieved.

[0034] Please see Figures 2 to 4 Furthermore, in some embodiments, in order to prevent the molten material from falling into the first vent 310 and causing the first vent 310 to become blocked, the first vent 310 and the second vent 210 are arranged alternately in the circumferential direction.

[0035] Specifically: On the assembled pipe assembly, the first air outlet 310 is located on the inner pipe wall, and the second air outlet 210 is located on the outer pipe wall. They are staggered circumferentially, meaning that when viewed along the circumference of the pipe, the radial projection of any second air outlet 210 does not coincide with any corresponding first air outlet 310. This staggering can manifest as uniform staggering, grouped staggering, or a spiral-like relative distribution along the circumference. The first air outlet 310 can be any of a slit, a circular hole, or a polygonal small hole, and the second air outlet 210 can be a long, narrow slit or a linear window composed of several connected openings. To ensure the stability of the staggered relationship during use, anti-rotation fits, limiting surfaces, or marking lines can be provided in the relative rotation direction of the two pipes to achieve the predetermined circumferential staggering during assembly and positioning. The edges of the air outlets can be chamfered or polished to reduce local separation and vortex desorption.

[0036] During gas supply, protective gas is injected from the first outlet 310 into the flow channel between the two pipe fittings and spreads along the circumference and axial direction of the channel. When the airflow tends to be ejected directionally from the second outlet 210, due to the staggered relationship between the inner and outer outlets in the circumference, the first outlet 310 is not directly below or opposite the outer opening, thus avoiding the formation of a through-flow straight jet channel. When molten metal and splashes fall along the direction of gravity or are carried by the airflow, they are difficult to directly enter the first outlet 310, and the airflow in the annular gap is less prone to short-circuiting and pulsation. During operation, first complete the circumferential positioning and locking of the pipe fittings, then turn on the gas supply and observe the continuity of the air curtain at the outer opening. If necessary, fine-tune the clamping posture to ensure that the outer opening remains aligned with the target area without disrupting the staggered relationship.

[0037] It should be noted that the staggered angular distance should be greater than the characteristic opening size of the first outlet 310 to ensure that the radial projections do not overlap; the staggered distribution should preferably match the length direction of the second outlet 210, so that the branch airflows from different first outlets 310 converge at the outer opening without colliding with each other. During assembly, control the coaxiality and circular runout of the two fittings to avoid circumferential misalignment and drift during rotation. During use, regularly clean the splashes adhering to the edge of the outer opening to maintain a stable outflow boundary under the staggered arrangement.

[0038] This staggered arrangement is suitable for metal laser welding conditions involving molten droplets, spatter, and thermal radiation. In welding stations equipped with exhaust ventilation and shielding facilities, the staggered arrangement can be maintained in conjunction with existing fixtures or robotic end effectors. The type and supply parameters of the shielding gas are determined according to the material and process, but sufficient pressure differential and flow rate within the staggered channels must be ensured to maintain a continuous gas curtain.

[0039] In some optional embodiments, the staggered arrangement can be a single-row distribution with uniform circumferential offset, or a multi-row distribution with mutual spacing; the first air outlet 310 can adopt a mixed arrangement of slits and orifices to obtain a more uniform circumferential air supply under staggered conditions; the second air outlet 210 can adopt a continuous slit shape or an intermittent slit shape, both of which maintain a non-overlapping projection with the staggered relationship. For ease of maintenance, the first air outlet 310 can be set on a pipe section that is easy to disassemble and assemble, enabling quick replacement while maintaining the staggered relationship.

[0040] In this embodiment, due to the technical means of staggering the first air outlet 310 and the second air outlet 210 in the circumferential direction, the molten material and splashes are difficult to fall directly into the gas supply side opening along the direction of gravity, and the annular gap airflow is not easy to form a straight short circuit between the inner and outer openings. This effectively solves the technical problems of easy blockage on the gas supply side and unstable air curtain in the prior art, thereby achieving the technical effects of continuous and stable adhesion of protective gas in the target area, improved anti-oxidation ability and reduced maintenance frequency.

[0041] Furthermore, in some embodiments, in order to prevent the protective gas from leaking out, the blowing pipe also includes a sealing ring disposed in the annular gap between the first pipe fitting 30 and the second pipe fitting 20, for sealing the annular gap so that the protective gas entering the annular gap from the first outlet 310 is ejected only through the second outlet 210.

[0042] Specifically: The sealing ring is disposed within the annular gap and can be placed in an annular groove on the outer surface of the first pipe fitting 30 or in an annular groove on the inner wall of the second pipe fitting 20. Alternatively, it can be axially limited by a stepped shoulder to maintain a stable fit. The sealing ring is preferably a circular ring made of an elastomer or composite material, with a circular, rectangular, or lip-shaped cross-section to form contact surfaces in both the radial and axial directions, accommodating thermal expansion and assembly tolerances. An interference fit or slight pre-compression is formed between the sealing ring and the opposing mating surfaces. Circumferential sealing of the annular gap is achieved through contact surface tension and material elasticity, thereby confining the air passage between the first outlet 310 and the second outlet 210 within a controlled area between the sealing rings. To reduce wear and adhesion, surface densification, anti-adhesion, or micro-texturing treatments can be applied to the sealing ring or the opposing mating surfaces, and heat-resistant and media-resistant material systems can be selected to adapt to the welding environment.

[0043] During gas supply, the protective gas enters the annular gap from the inner cavity of the first pipe fitting 30 through the first outlet 310. It is then constrained by the closed boundaries formed by the sealing ring in the axial and circumferential directions, allowing it to travel only along the defined gas path and be directionally ejected from the second outlet 210. The sealing ring blocks leakage channels from the annular gap to both ends and non-target locations, enabling the static pressure within the annular gap to be established and maintained stable. Start-up and shutdown operations should follow the sequence of stabilizing pressure before welding, and stopping welding before gradually reducing pressure, to maintain a continuous air curtain at the second outlet 210 and prevent transient backflow.

[0044] It should be noted that during assembly, the fit and compression of the sealing ring and the annular groove should be within a reasonable range to ensure they remain in close contact without excessive wear under pressure, heat, and vibration. The chamfers and fillets of the sealing ring and mating surfaces should be smooth to avoid shear damage. The position of the sealing ring should ideally match the axial correspondence of the first air outlet 310 and the second air outlet 210 to form an effective controlled air supply chamber and reduce unnecessary pressure drop. During operation, the surface of the sealing ring should be regularly inspected for ablation, cracking, and metal spatter adhesion; cleaning and replacement should be performed as necessary.

[0045] In this embodiment, by using a sealing ring in the annular gap between the first pipe 30 and the second pipe 20 to seal the annular gap, the protective gas entering from the first outlet 310 is ejected only through the second outlet 210. This effectively solves the technical problems of unstable air curtain and insufficient directionality caused by leakage at the end of the annular gap and in the non-target direction in the prior art. As a result, it achieves the technical effects of forming a continuous and stable directional protective airflow in the target area, improving the antioxidant capacity, and reducing gas consumption and maintenance frequency.

[0046] Furthermore, in some embodiments, there are two sealing rings, which are located on both sides of the first air outlet 310 and the second air outlet 210 along the axial direction of the first pipe 30, respectively, so as to form an air supply chamber through the outer surface of the first pipe 30, the inner wall of the second pipe 20 and the opposite sides of the two sealing rings.

[0047] Specifically: The first pipe fitting 30 is inserted into and coaxial with the second pipe fitting 20, forming a continuous annular gap between them. Along the axial direction of the first pipe fitting 30, two sealing rings are respectively provided at opposite ends near the first air outlet 310 and the second air outlet 210. The sealing rings can be fitted into an annular groove on the outer surface of the first pipe fitting 30 or into an annular groove on the inner wall of the second pipe fitting 20. After assembly, the sealing rings and their mating surfaces form a circumferential fit, thereby forming a controlled air supply chamber between the opposite sides of the two sealing rings, with the outer surface of the first pipe fitting 30 and the inner wall of the second pipe fitting 20 as the boundary. The sealing rings are preferably made of heat-resistant and media-resistant elastic materials or elastic composite materials, and their cross-section can be circular, rectangular, or have a lipped sealing section to obtain a stable sealing line in both the radial and axial directions. To reduce wear and adhesion, the working surface or mating metal surface of the sealing ring can be polished, densified, or treated with anti-adhesion agents. The first air outlet 310 and the second air outlet 210 are axially corresponding to each other, and the air supply chamber spans the axial section between them, so that the gas entering the annular gap from the first air outlet 310 is uniformly pressurized in the chamber and then directionally ejected from the second air outlet 210.

[0048] The protective gas enters the inner cavity of the first pipe 30 from the gas source, and after being injected into the annular gap through the first outlet 310, it enters the gas supply chamber surrounded by two sealing rings. Because the sealing rings axially block both ends of the gas supply chamber, the gas within the annular gap is confined to establish a stable static pressure within the chamber, and can only be ejected radially through the second outlet 210, forming a protective gas curtain pointing towards the target area. During start-up and shutdown, the pressure is stabilized before operation, and during shutdown, the heat source is stopped before the pressure is gradually reduced to ensure a smooth pressure transition within the chamber and maintain continuous jet flow.

[0049] During assembly, control the interference fit between the sealing ring and the annular groove to ensure a tight fit without excessive wear under thermal expansion and contraction and vibration conditions. The transition between the sealing ring and the metal chamfer should be smooth to avoid shear damage to the ring. The axial distance between the two sealing rings should cover the connecting section between the first air outlet 310 and the second air outlet 210 without obstructing the effective cross-section of the two openings. During operation, regularly check the sealing ring surface for cracks, ablation, or spatter adhesion, and keep the mating surfaces clean and adequately lubricated to reduce fretting wear.

[0050] In this embodiment, by employing a technique of setting two sealing rings in the annular gap between the first pipe 30 and the second pipe 20, and using the opposing sides of the two sealing rings to form a gas supply cavity with the outer surface of the first pipe 30 and the inner wall of the second pipe 20, the technical problems of axial leakage in the annular gap leading to difficulty in establishing cavity pressure, unstable jet flow, and insufficient directionality in the prior art are effectively solved. This achieves the technical effect of stable ejection of protective gas only through the second outlet 210, forming a continuous directional air curtain in the target area, and improving the anti-oxidation effect and gas consumption utilization rate.

[0051] Please see Figures 3 to 4 Furthermore, in some embodiments, the second air outlet 210 is a narrow slit, the long axis of which is parallel to the axis of the second pipe 20 and continuously opened along the generatrix direction of the second pipe 20. The first air outlet 310 can be any one of a slit, a round hole, a square hole, or an irregularly shaped hole.

[0052] Specifically: The second air outlet 210 is located on the wall of the second pipe fitting 20 and is a narrow, elongated slit continuously opened along the generatrix of the pipe fitting, with the long axis of the slit parallel to the axis of the pipe fitting. The edges on both sides of the slit can be chamfered or slightly rounded to reduce boundary layer separation and enhance airflow adhesion. The slit can be positioned close to the generatrix of the target joint to form a protective air curtain that approximates a line source.

[0053] The first air outlet 310 is disposed on the pipe wall of the first pipe fitting 30. The orifice shape can be a slit, a round hole, a square hole, or an irregularly shaped hole. Preferably, several air supply branches are formed in the circumferential or axial direction so that the gas inside the cavity of the first pipe fitting 30 is injected through the pipe wall into the flow channel between the two pipe fittings and uniformly supplied to the narrow slit. The orifice edge of the first air outlet 310 can be polished to reduce local nozzle loss and suppress vortex shedding.

[0054] The protective gas is injected from the inner cavity of the first pipe 30 through the first outlet 310 into the flow channel between the two pipes. After completing dynamic pressure diffusion and static pressure homogenization within the channel, it is directionally ejected through the narrow slit on the second pipe 20. Because the slit is continuous along the generatrix and its long axis is parallel to the axis, the ejected gas flow forms a nearly uniform linear air curtain in the target area, which can continuously cover the area as the welding heat source moves along the joint. During start-up and shutdown, a stable gas supply is established first, and then welding operations are carried out; at the end, the heat source is stopped first, and then the gas supply is gradually reduced to maintain the continuity of the air curtain at the joint and avoid transient backflow.

[0055] The width and edge smoothness of the second outlet 210 affect the shear layer and adhesion of the jet stream; therefore, it is advisable to ensure neat edges and a dense surface. The axial and circumferential correspondence between the first outlet 310 and the narrow slit should facilitate pressure drop distribution and uniform supply within the channel, avoiding localized short circuits or pulsations. During assembly, the coaxiality and circular runout of the two pipe fittings should be kept within a controllable range to ensure the straightness and gap stability of the continuous slit along the generatrix direction.

[0056] In some optional embodiments, the elongated slit of the second outlet 210 can be straight or slightly curved in the generatrix direction to conform to the mounting surface. The slit opening can adopt an outward-expanding or inward-retracting micro-flare transition to reduce ejection pressure loss. The first outlet 310 can be arranged in a combination of slits and round, square, or irregularly shaped holes. By changing the hole shape and distribution density, the pressure field within the channel can be modified, improving the flow uniformity of the elongated slit along its length. In terms of processing, the elongated slit and various orifices can be formed by machining, laser cutting, or electrical discharge machining, and the outlet edges can be treated with wear-resistant and anti-adhesion treatments to reduce splash deposition.

[0057] In this embodiment, by employing a narrow, elongated slit continuously opened along the generatrix of the second pipe fitting 20 wall with its long axis parallel to the axis as a directional linear air outlet, and combining this with the first air outlet 310 on the wall of the first pipe fitting 30, which can be a slit, round hole, square hole, or irregularly shaped hole for uniform supply, the technical problems of discontinuous air curtain, uneven coverage, and insufficient directionality caused by point or discrete openings in the prior art are effectively solved. This achieves the technical effects of forming a continuously attached linear air curtain of protective gas in the target area, improving oxidation resistance, and enhancing weld formation stability. Please see Figures 1 to 4 In some embodiments, the air blowing pipe further includes an adjusting pipe 10, which is sleeved on the outside of the second pipe fitting 20 and can move along the axial direction of the second pipe fitting 20. The adjusting pipe 10 is used to partially block the second air outlet 210 to adjust the effective opening length of the second air outlet 210.

[0058] Specifically: The regulating tube 10 is a hollow cylindrical component, with its inner wall slidingly engaging with the outer surface of the second tube 20 to ensure smooth axial movement and positioning. The outer surface of the regulating tube 10 may have an operating section and anti-slip texture to facilitate minute displacement adjustments within the welding fixture or robot end effector space. To improve the clarity of the shielding boundary, the regulating tube 10 has a continuous solid wall section in the area corresponding to the second air outlet 210. The edges of the solid wall section are chamfered or slightly rounded to reduce eddies and jet tearing near the shielding edge. A circumferential limiting shoulder or anti-reverse structure may be provided between the second tube 20 and the regulating tube 10 to prevent the regulating tube 10 from overstepping its bounds and completely sealing the second air outlet 210. If necessary, an unlockable clamping assembly can be provided on the outside of the regulating tube 10 to maintain its position after adjustment.

[0059] During gas supply, the protective gas reaches the second outlet 210 through the inner channel, forming an external jet. By pushing the regulating pipe 10 axially, the solid wall section covers the second outlet 210 for different lengths, thereby continuously changing the effective opening length and equivalent nozzle area. When the effective opening is shortened, the jet stream is more concentrated and the local dynamic pressure is increased, which is suitable for shorter welds or conditions requiring localized reinforcement protection; when the effective opening is lengthened, the coverage area of ​​the linear air curtain increases, which is suitable for longer welds or higher travel speeds. After adjustment, the position of the regulating pipe 10 is maintained, and the uniformity and adhesion of the jet at the second outlet 210 are checked.

[0060] The clearance between the regulating pipe 10 and the second fitting 20 should balance smooth movement and stable posture to avoid drifting of the shielding edge due to excessive side clearance. The relative straightness of the solid wall section of the regulating pipe 10 and the second air outlet 210 affects the uniformity of the jet cross-section; coaxiality and circular runout should be checked during assembly. During operation, the regulating pipe 10 should be moved slowly to observe changes in the jet pattern and locked after achieving the target coverage. If thermal expansion and contraction or vibration occurs at the workstation, anti-loosening design should be considered at the adjustment position. The surface near the shielding edge should be kept clean to prevent splash adhesion from altering the effective opening profile.

[0061] In some optional embodiments, the regulating tube 10 may be made of metal or heat-resistant engineering materials, and its inner wall may be provided with a low-friction lining to reduce sliding resistance; the adjustment method may be manual fine adjustment or segmented positioning through elastic locking or external micro-actuation structure; the solid wall section may be designed as a straight blocking edge or a slightly arc-shaped blocking edge to match the geometry of the second air outlet 210 in the generatrix direction; without changing the blocking principle, a narrow observation window may be added to the end of the regulating tube 10 for visual calibration of the effective opening position under safe conditions.

[0062] In this embodiment, the technical means of using an adjusting pipe 10 sleeved outside the second pipe fitting 20 and movable along the axial direction to partially block the second air outlet 210 and adjust the effective opening length effectively solves the technical problems in the prior art where the coverage range is difficult to match different weld lengths and travel speeds due to the fixed geometry of the directional air outlet, the uncontrollable air curtain distribution, and the low gas utilization rate. Thus, it achieves the technical effects of adjustable protective airflow coverage and dynamic pressure distribution as needed, more stable adhesion of welding area protection, and reduced gas consumption and changeover time.

[0063] Furthermore, in some embodiments, a filler is provided between the inner wall of the regulating tube 10 and the outer surface of the second tube 20 to seal the gap between them.

[0064] Specifically: To suppress leakage at the mating point, a filler is provided between the inner wall of the regulating pipe 10 and the outer surface of the second fitting 20. The filler can be annular or segmented sealing elements, preferably fitted into the annular receiving area of ​​the inner wall of the regulating pipe 10, or it can be fitted into the annular bearing area of ​​the outer surface of the second fitting 20. A circumferentially continuous contact band is formed between the filler and the opposing surface, and a stable seal is achieved through appropriate pre-compression. The filler material can be selected from heat-resistant elastomers, graphite-modified fiber composite materials, polytetrafluoroethylene-coated elastic core materials, metal spring-reinforced composite sealing strips, etc.; the cross-sectional shape can be circular, rectangular, lip-shaped, or composite lip to balance sealing performance and movement resistance. To reduce wear and jamming, the contact surfaces can be refined by polishing, densification, or solid lubricating coating treatment, and a simple shoulder is provided at the end of the regulating pipe 10 to prevent accidental dislocation.

[0065] During gas supply, the protective gas from the inside reaches the external opening through a predetermined channel, forming a jet. During axial movement of the regulating pipe 10, the filler remains in contact with the outer surface of the second pipe fitting 20, blocking leakage paths along the axial and circumferential directions in the fitting gap, allowing the gas to escape through the fitting gap and be concentrated and ejected from the target opening. During operation, first confirm that the filler is properly assembled and the pre-pressure is uniform, then supply gas and observe the jet flow. When adjustment of the effective opening is needed, smoothly move the regulating pipe 10 axially, and after confirming that the spray pattern and coverage area remain continuous, hold the regulating pipe 10 in position.

[0066] The clearance should match the compression of the filler to ensure a seal is maintained without excessively increasing frictional resistance under conditions of thermal expansion and contraction and vibration. The filler interface should preferably use a butt joint or bevel joint with a chamfered inlet to prevent scratches and warping. The circular runout and coaxiality of the opposing surfaces should be controlled within a range conducive to uniform circumferential contact. During use, regularly clean away any splashes and dust, check the filler surface for cracks, hardening, or wear, and replace it if necessary.

[0067] In this embodiment, by using a filler between the inner wall of the regulating pipe 10 and the outer surface of the second pipe 20 and sealing the gap between them, the technical problem of jet attenuation and insufficient directionality caused by gas escaping through the gap at the regulating mechanism in the prior art is effectively solved. This achieves the technical effect of concentrated protective gas being stably ejected from the target opening, continuous coverage of the air curtain, and reduced gas consumption and maintenance frequency.

[0068] The above description in this specification is merely illustrative of the present invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the content of this specification or exceed the scope defined in the claims, all of which shall fall within the protection scope of this invention.

Claims

1. A laser welding air blower, suitable for welding the seams of automotive door ring splices, characterized in that, include: The second fitting has a second air outlet on its pipe wall that communicates with the outer surface; The first pipe fitting is inserted inside the second pipe fitting, and an annular gap is formed between the first pipe fitting and the second pipe fitting. A first air outlet communicating with the outer surface is opened on the pipe wall of the first pipe fitting. One end of the first pipe fitting is closed, and the other end is used to communicate with a gas source supplying protective gas. The second air outlet is configured to face and be directly opposite the seam of the door ring splice when in use.

2. The air blowing pipe according to claim 1, characterized in that, The first air outlet and the second air outlet are arranged alternately in the circumferential direction.

3. The air blowing pipe according to claim 2, characterized in that, It also includes a sealing ring, which is disposed in the annular gap between the first pipe and the second pipe to seal the annular gap, so that the protective gas entering the annular gap from the first outlet is ejected only through the second outlet.

4. The air blowing pipe according to claim 1, characterized in that, The first pipe fitting and the second pipe fitting are coaxially arranged.

5. The air blowing pipe according to claim 1, characterized in that, The second air outlet is a narrow slit, the long axis of which is parallel to the axis of the second pipe and is continuously opened along the generatrix direction of the second pipe.

6. The air blowing pipe according to any one of claims 1 to 5, characterized in that, The first air outlet can be any one of a slit, a round hole, a square hole, or an irregularly shaped hole.

7. The air blowing pipe according to claim 3, characterized in that, The number of sealing rings is two, and the two sealing rings are located on both sides of the first air outlet and the second air outlet along the axial direction of the first pipe, respectively, so as to form an air supply cavity through the outer surface of the first pipe, the inner wall of the second pipe, and the opposite sides of the two sealing rings.

8. The air blowing pipe according to claim 1, characterized in that, It also includes an adjusting pipe, which is sleeved on the outside of the second pipe and can move along the axial direction of the second pipe. The adjusting pipe is used to partially block the second air outlet to adjust the effective opening length of the second air outlet.

9. The air blowing pipe according to claim 8, characterized in that, A filler is provided between the inner wall of the regulating tube and the outer surface of the second pipe fitting to seal the gap between them.

10. The air blowing pipe according to claim 3 or 7, characterized in that, The first air outlet is configured as at least one along the axial direction of the first pipe fitting, and forms a connecting air passage with the second air outlet, consisting of the first air outlet, the annular gap, and the second air outlet.

Images