A gas shielded laser welding device and welding method for niobium alloy in atmospheric environment

Abstract

The present invention relates to a gas protection laser welding device and a welding method for niobium alloys in an atmospheric environment. The device includes a protective gas support cover, an adjustment mechanism, a first air jetting mechanism, and a second air jetting mechanism. A workpiece to be welded is placed below the protective gas support cover, and the weld seam of the workpiece is correspondingly arranged with the protective gas support cover; one end of the adjustment mechanism is installed on the protective gas support cover, and the other end of the adjustment mechanism is installed with a laser welding gun of the laser welding device, and the light-emitting point of the laser welding gun is correspondingly arranged with the weld seam of the workpiece; both the first air jetting mechanism and the second air jetting mechanism are installed in the protective gas support cover, both the first air jetting mechanism and the second air jetting mechanism are correspondingly arranged with the weld seam of the workpiece, and the first air jetting mechanism is located between the light-emitting point of the laser welding gun and the second air jetting mechanism. The present invention can weld niobium alloys with a relatively small degree of oxidation in an atmospheric environment, reduce the cost of using a vacuum chamber, and improve the welding efficiency; it can adapt to a certain weld gap and weld misalignment during welding to ensure a good welding effect.

Description

Technical Field

[0001] The invention relates to the technical field of nozzle welding, and in particular to a gas shielded laser welding device and a welding method for a niobium alloy in an atmospheric environment. Background Art

[0002] The nozzle is an important part of the rocket engine. It is a device that accelerates the airflow by changing the geometric shape of the inner wall of the pipe section. In the rocket engine, the flow rate of the gas is controlled by the size of the nozzle throat area, so that the gas in the combustion chamber maintains a predetermined pressure, and the propellant combustion products are accelerated through the nozzle expansion, and its thermal energy is fully converted into the kinetic energy of the gas, so that the engine obtains propulsion power. At present, most of the existing liquid rocket engine main engine nozzles in China are jacket structures, which have the advantage of relatively mature manufacturing processes, usually using vacuum brazing, argon arc welding, laser welding and other processes.

[0003] However, the manufacturing of jacketed nozzles has the following problems: 1. The structure itself is relatively heavy, which is not conducive to improving the thrust-to-weight ratio of the engine; 2. Since vacuum brazing and laser welding have relatively strict requirements on the gap between the inner and outer walls of the jacketed nozzle, and the larger the nozzle size, the more difficult it is for the front machining process to control the gap between the inner and outer walls, it is difficult to manufacture large-diameter jacketed nozzles.

[0004] Therefore, the single-wall nozzle has irreplaceable advantages, which are: 1. The overall weight of the single-layer structure is more advantageous, which is conducive to improving the thrust-to-weight ratio of the engine; 2. The single-layer structure can obtain a large-sized nozzle by adopting the welding method, so that the rocket can obtain a greater specific impulse.

[0005] Niobium alloy is the preferred material for single-wall nozzles due to its high melting point and good high-temperature performance. However, tests have found that niobium alloy has poor oxidation resistance. Once oxidized, the performance of the material will drop sharply. When welding in an atmospheric environment, the weld area and heat-affected zone are very easy to oxidize, and the welding effect is not ideal. In addition, niobium alloy will have a certain weld gap and weld wall misalignment during welding, which will also affect the welding effect.

[0006] At present, the best option is to use vacuum electron beam welding of niobium alloy in a large-sized vacuum chamber, which can obtain welds with good welding performance and excellent mechanical properties. However, in actual engineering applications, the price of using a large-sized vacuum chamber is very expensive, the cost is high, and the vacuuming efficiency is low, and the welding efficiency is also very low, which is not suitable for mass production.

[0007] Therefore, how to weld niobium alloys with a lower degree of oxidation in a non-vacuum environment (atmospheric environment) to reduce the cost of using a large-size vacuum chamber and improve welding efficiency, while also being able to adapt to a certain weld gap and weld wall offset during welding to ensure a good welding effect, has become an urgent problem to be solved. Summary of the invention

[0008] The purpose of the present invention is to provide a gas shielded laser welding device and a welding method for niobium alloy in an atmospheric environment to solve the problems existing in the above-mentioned prior art.

[0009] To achieve the above object, the present invention provides the following solutions:

[0010] The present invention provides a gas shielded laser welding device for niobium alloy in an atmospheric environment, comprising a shielding gas support cover, an adjustment mechanism, a first jet mechanism and a second jet mechanism, wherein:

[0011] A workpiece to be welded is placed below the protective gas support cover, and the weld of the workpiece is arranged corresponding to the protective gas support cover;

[0012] One end of the adjustment mechanism is mounted on the protective gas support cover, and the other end of the adjustment mechanism is mounted with a laser welding gun of the laser welding device, wherein a light emitting point of the laser welding gun is arranged corresponding to a weld seam of the workpiece;

[0013] The first jet mechanism and the second jet mechanism are both installed in the protective gas support cover, and the first jet mechanism and the second jet mechanism are both set corresponding to the weld of the workpiece, the first jet mechanism is located between the light outlet point of the laser welding gun and the second jet mechanism, the first jet mechanism is used to protect the molten metal during the welding process of the workpiece, and the second jet mechanism is used to protect the weld metal in a high temperature state during the welding process of the workpiece.

[0014] According to one embodiment of the present invention, the adjustment mechanism includes a height adjustment rod, which is vertically arranged, and the bottom end of the height adjustment rod is installed on the top of the protective gas support cover, and the top of the height adjustment rod is bolt-fixedly slidably installed with a second adjustment block, and the relative sliding direction between the second adjustment block and the height adjustment rod is arranged along the length direction of the height adjustment rod; the second adjustment block is bolt-fixedly slidably installed with a first adjustment block, and the relative sliding direction between the first adjustment block and the second adjustment block is arranged horizontally and along the direction of the first jet mechanism approaching or away from the light outlet point of the laser welding gun; the first adjustment block is bolt-fixedly slidably installed with a second connecting block, and the relative sliding direction between the second connecting block and the first adjustment block is arranged horizontally and perpendicular to the relative sliding direction between the first adjustment block and the second adjusting block, and the laser welding gun of the laser welding device is detachably installed at the end of the second connecting block.

[0015] According to one embodiment of the present invention, a first connecting block is rotatably installed on the top of the protective gas support cover, the end of the first connecting block is rotatably connected to the bottom end of the height adjustment rod, and the height adjustment rod is installed on the top of the protective gas support cover through the first connecting block.

[0016] According to an embodiment of the present invention, the height adjustment rod is a polygonal column structure.

[0017] According to one embodiment of the present invention, the first jet mechanism includes an oblique air outlet tunnel opened at the bottom end of the protective gas support cover, and the oblique air outlet tunnel is located between the light outlet point of the laser welding gun and the second jet mechanism; the bottom end of the oblique air outlet tunnel is arranged corresponding to the weld of the workpiece, and a first air pipe is installed on the protective gas support cover, and the top end of the oblique air outlet tunnel is connected to the first air pipe.

[0018] According to one embodiment of the present invention, the angle between the bottom end of the oblique air outlet tunnel and the bottom end of the protective air support cover is or is substantially 45°.

[0019] According to one embodiment of the present invention, the second jet mechanism includes a third air pipe installed in the protective gas support cover, a second air pipe is installed on the protective gas support cover, and one end of the second air pipe is connected with one end of the third air pipe; a ventilation groove is opened at the bottom end of the protective gas support cover, and the oblique air outlet tunnel is located between the ventilation groove and the light outlet point of the laser welding gun; the top end of the ventilation groove is connected with the third air pipe, and a first orifice plate is fixedly installed on the inner wall of the bottom end of the ventilation groove, and the first orifice plate is arranged corresponding to the weld of the workpiece; the ventilation groove and the third air pipe are independently arranged from the oblique air outlet tunnel.

[0020] According to an embodiment of the present invention, the third air pipe is located at the top of the ventilation groove, and a second orifice plate is provided between the third air pipe and the first orifice plate, and the inner wall of the ventilation groove is fixedly connected to the side wall of the second orifice plate.

[0021] According to one embodiment of the present invention, one end of the third air pipe close to the oblique air outlet tunnel is connected to a plurality of branch air pipes, and the branch air pipes are independently arranged from the oblique air outlet tunnel; the third air pipe and the branch air pipe are each provided with a plurality of ventilation holes corresponding one-to-one to the holes on the second orifice plate, a small tube is arranged between each hole on the second orifice plate and the corresponding ventilation hole, and both ends of each small tube are respectively fixedly connected to the second orifice plate and the corresponding ventilation hole; the third air pipe and the branch air pipe are both connected to the ventilation groove through the ventilation holes and the small tubes.

[0022] The present invention also provides a welding method of a niobium alloy using a gas shielded laser welding device in an atmospheric environment, comprising the steps of using the above-mentioned device to perform welding, which includes:

[0023] S1, placing the weld of the workpiece below the light-emitting point of the laser welding gun;

[0024] S2. Vertically adjust the protective gas support cover so that the distance between its bottom and the top of the workpiece is 1.5 mm-2.5 mm;

[0025] S3, adjusting the level of the protective gas support cover in step S2, so that the first jet mechanism and the second jet mechanism are centered with the weld of the workpiece, and the distance between the bottom end of the oblique air outlet tunnel and the light outlet point of the laser welding gun is 3 mm-5 mm;

[0026] S4, adjusting the focal height of the laser welding gun light output point so that the distance between it and the weld of the workpiece is 3mm-6mm;

[0027] S5, connecting the first air pipe and the second air pipe to an external air blowing device and starting them;

[0028] S6, starting the laser welding gun and moving the laser welding device forward along the direction of the weld of the workpiece, while welding the weld of the workpiece by laser swing welding.

[0029] The present invention has at least the following technical effects:

[0030] The present invention provides a gas shielded laser welding device and a welding method for niobium alloys in an atmospheric environment. The present invention can jet the molten metal of the niobium alloy in the welding process and the weld metal in a high temperature state through the arrangement of a first jet mechanism and a second jet mechanism, and then the niobium alloy can be welded with a small degree of oxidation in a non-vacuum (atmospheric environment), so that the weld performance coefficient reaches more than 90% of the parent material, thus reducing the cost of using a large-size vacuum chamber and improving the welding efficiency. At the same time, the welding method provided by the present invention can also adapt to a certain weld gap and weld staggered wall during welding, thereby ensuring a good welding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 for Figure 1 A front view of

[0034] Figure 3 for Figure 2 The cross-sectional view along the AA direction;

[0035] Figure 4 for Figure 3 A partial enlarged view of point B in the middle;

[0036] Figure 5 It is a schematic diagram of the overall structure of the protective gas support cover in the present invention from the side view;

[0037] Figure 6 It is a schematic diagram of the overall structure of the protective gas support cover in the present invention from the bottom side;

[0038] Figure 7 for Figure 6 A front view of

[0039] Figure 8 for Figure 6 The cross-sectional view along the TT direction;

[0040] Fig. 9 for Figure 7 Side view of

[0041] Fig.10 for Fig. 9 A cross-sectional view along the FF direction;

[0042] Fig.11 for Fig. 9 The cross-sectional view along the GG direction;

[0043] Fig.12 It is a schematic diagram of the overall structure of the first adjustment block and the second connection block in the present invention;

[0044] Fig.13 Schematic diagram of the positional relationship between the focus of the light-emitting point of an exemplary laser welding gun of the present invention and the surface of a workpiece;

[0045] Fig.14 A schematic diagram of a swing trajectory of a light-emitting point of an exemplary laser welding gun of the present invention;

[0046] Among them, 1. protective gas support cover; 2. first connecting block; 3. height adjustment rod; 4. first adjusting block; 5. second adjusting block; 6. second connecting block; 7. first air pipe; 8. second air pipe; 9. workpiece; 10. first orifice plate; 11. third air pipe; 12. branch air pipe; 13. second orifice plate; 14. oblique air outlet tunnel. DETAILED DESCRIPTION

[0047] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are used to illustrate the principles of the present invention, and are not configured to limit the present invention. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the sizes of some structural components or areas in the drawings may be enlarged for other structural components or areas to help understand the embodiments of the present invention.

[0048] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the embodiments of the present invention. In the description of the present invention, it should be noted that, unless otherwise specified, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0049] In addition, the terms "include", "comprise", "have" or any other variations thereof are intended to cover non-exclusive inclusion, so that a structure or component including a series of elements includes not only those elements, but also other mechanical elements that are not explicitly listed or inherent in the structure or component. In the absence of more restrictions, the elements defined by the sentence "include..." do not exclude the existence of other identical elements in the article or device including the elements.

[0050] Spatially related terms such as "below", "beneath", "under", "low", "above", "on", "high", etc. are used to facilitate description to explain the positioning of one element relative to a second element, indicating that these terms are intended to cover different orientations of the device in addition to orientations different from those shown in the figures. In addition, for example, "one element is above / below another element" can mean that the two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first", "second", etc. are also used to describe various elements, regions, parts, etc., and do not specifically refer to the meaning of order or sequence, and should not be regarded as limiting. Similar terms are used throughout the description to represent similar elements.

[0051] For those skilled in the art, the present invention can be implemented without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention.

[0052] Reference Figure 1-3The present invention provides a gas shielded laser welding device for niobium alloy in an atmospheric environment, comprising a shielding gas support cover 1, an adjustment mechanism, a first jet mechanism and a second jet mechanism, wherein:

[0053] A workpiece 9 to be welded is placed below the shielding gas support cover 1 , and the weld of the workpiece 9 is arranged corresponding to the shielding gas support cover 1 . Preferably, the weld of the workpiece 9 is arranged at the center position just below the shielding gas support cover 1 .

[0054] In this embodiment, refer to Figure 1 The workpiece 9 is divided into two parts, and preferably niobium alloy plates are used as the two workpieces 9 to be welded, with a thickness of 1 mm to 2 mm, and the shape of the weld can be a straight line. Those skilled in the art can also use the laser welding device of the present invention to weld welds of niobium alloy plates of other shapes, such as curved welds, according to actual conditions, which are not particularly limited here.

[0055] In this embodiment, refer to Figure 5 , Figure 7 or Fig. 9 The shape of the protective gas support cover 1 can be roughly a polygonal column with a trapezoidal vertical cross-section, and the length direction is set along the weld of the workpiece 9.

[0056] One end of the adjustment mechanism is installed on the protective gas support cover 1, preferably rotatably installed on the top of the protective gas support cover 1, and the adjustment mechanism can be used to accurately and quantitatively adjust the position of the protective gas support cover 1; the other end of the adjustment mechanism is installed with a laser welding gun (not shown in the figure) of the laser welding device, and the light emitting point of the laser welding gun (i.e., the laser welding gun head) is set corresponding to the weld of the workpiece 9. Preferably, the light emitting point of the laser welding gun is set just above the weld of the workpiece 9, so that subsequent welding work can be better performed.

[0057] Laser welding guns are prior art known to those skilled in the art, such as fiber laser welding guns and solid-state laser welding guns known in the art. Those skilled in the art may also select different types of laser welding guns according to actual welding conditions, and disassemble and install them in the adjustment mechanism, which is not particularly limited here.

[0058] The laser welding device disclosed in the present invention can be installed on a robot, and the welding of the weld seam of the workpiece 9 can be achieved through the automatic control of the robot. Among them, the use of robots to automatically control welding is a prior art known in the art. During welding, the robot can control the laser welding gun on the device to move along the weld seam of the workpiece 9, thereby achieving welding of the weld seam of the workpiece 9.

[0059] The first jet mechanism and the second jet mechanism are both installed in the protective gas support cover 1, and the first jet mechanism and the second jet mechanism are both arranged corresponding to the weld of the workpiece 9, and preferably the first jet mechanism and the second jet mechanism are arranged just above the weld of the workpiece 9. The first jet mechanism is located between the light outlet point of the laser welding gun and the second jet mechanism.

[0060] When the laser welding gun welds the weld of the workpiece 9, the laser emitted by the laser welding gun will melt the metal on both sides of the weld of the workpiece 9 into a molten state, thereby realizing the welding of the weld of the workpiece 9; wherein, since the first jet mechanism is located between the light emitting point of the laser welding gun and the second jet mechanism, that is, after the weld of the workpiece 9 becomes molten, it will first be located below the first jet mechanism as the device moves. At this time, the metal near the weld of the workpiece 9 has not cooled down yet and is still in a molten state (i.e., a molten pool), and the first jet mechanism can spray on the weld of the workpiece 9 to avoid oxidation of the molten metal at the weld of the workpiece 9, thereby realizing a protective effect; at the same time, the flow of air can also be used to quickly cool the molten metal at the weld of the workpiece 9, thereby accelerating the cooling rate of the molten metal.

[0061] Then, the second jet mechanism will be located above the weld of the workpiece 9 as the device moves. At this time, the metal at the weld of the workpiece 9 will not be in a molten state, but in a solidified state, but the temperature is still high and will be in a high temperature state. The second jet mechanism can jet the weld of the workpiece 9 again, thereby playing a secondary protective role for the metal at the weld of the workpiece 9 in a high temperature state, preventing oxidation of the metal at the weld of the workpiece 9 for a second time, better avoiding the occurrence of oxidation, and further accelerating the cooling speed of the metal at the weld of the workpiece 9.

[0062] In addition, due to the deviation of the previous sheet metal process and the machining process, there will be a gap of 0.1mm-0.3mm or a misalignment of 0.1mm-0.4mm in some parts when the left and right niobium alloy workpieces 9 are welded. Therefore, during the welding process, a pressing method can be adopted, that is, the left and right niobium alloy workpieces 9 are pressed at the same time to reduce the misalignment to within 0.2mm, so that the welding work can be carried out better and smoothly.

[0063] In this embodiment, when the left and right niobium alloy workpieces 9 are pressed to reduce misalignment, a pressing component known to those skilled in the art, such as a C-type clamp or an F-type clamp, etc., may be used, without particular limitation.

[0064] According to one embodiment of the present invention, the adjustment mechanism includes a height adjustment rod 3. In this embodiment, referring to Figure 1The number of height adjustment rods 3 is preferably one, the height adjustment rod 3 is vertically arranged, and the bottom end of the height adjustment rod 3 is installed on the top of the protective gas support cover 1, preferably bolt-fixed and rotatably installed on the top of the protective gas support cover 1. The staff can loosen the bolts at the connection between the height adjustment rod 3 and the protective gas support cover 1 and adjust the inclination angle of the protective gas support cover 1 according to the actual situation, and tighten the bolts at the connection between the height adjustment rod 3 and the protective gas support cover 1 after the adjustment, so as to complete the adjustment of the inclination angle of the protective gas support cover 1.

[0065] The top of the height adjustment rod 3 is bolted and sleeved with a second adjustment block 5 which is slidably mounted; in this embodiment, refer to Figure 1 The second adjustment block 5 is preferably an I-shaped structure. The relative sliding direction between the second adjustment block 5 and the height adjustment rod 3 is set along the length direction of the height adjustment rod 3; when the height of the protective gas support cover 1 needs to be adjusted, the bolts at the connection between the second adjustment block 5 and the height adjustment rod 3 are loosened, and then the height adjustment rod 3 is made to slide upward or downward in the second adjustment block 5, thereby adjusting the height of the protective gas support cover 1; after adjustment, the bolts on the second adjustment block 5 are tightened to achieve re-fixation of the second adjustment block 5 and the height adjustment rod 3.

[0066] The second adjusting block 5 is bolted and fixed with a limited sliding installation on the first adjusting block 4. In this embodiment, refer to Figure 1 or Fig.12 The first adjustment block 4 is preferably a concave structure, and the I-shaped second adjustment block 5 is placed vertically, and the concave parts on both sides are respectively clamped on the outer wall of the opening of the first adjustment block 4 with the concave structure, thereby realizing the limited sliding connection between the second adjustment block 5 and the first adjustment block 4. The relative sliding direction of the first adjustment block 4 and the second adjustment block 5 is set horizontally and along the direction of the first jet mechanism approaching or away from the light-emitting point of the laser welding gun, that is, the opening of the first adjustment block 4 with the concave structure is set parallel to the length direction of the protective gas support cover 1, so as to ensure that the second adjustment block 5 can slide on the first adjustment block 4 along the length direction of the protective gas support cover 1, and then the distance between the first jet mechanism and the light-emitting point of the laser welding gun can be adjusted along the length direction of the protective gas support cover 1.

[0067] When it is necessary to adjust the distance between the first jet mechanism and the light-emitting point of the laser welding gun, loosen the bolt at the connection between the second adjustment block 5 and the first adjustment block 4, so that the second adjustment block 5 can be slid relatively on the first adjustment block 4; after adjustment, re-tighten the bolt at the connection between the second adjustment block 5 and the first adjustment block 4, so that the two can be re-fixed, thereby completing the adjustment of the distance between the first jet mechanism and the light-emitting point of the laser welding gun.

[0068] The first adjusting block 4 is bolted and fixed with a limited sliding installation on the second connecting block 6. In this embodiment, refer to Figure 1The second connecting block 6 is a bent L-shaped structure, one end of which is connected to the first adjusting block 4 in a limited sliding manner, and the other end of which is detachably connected to the laser welding gun through two bolts. The relative sliding direction of the second connecting block 6 and the first adjusting block 4 is set horizontally and is set vertically to the relative sliding direction of the first adjusting block 4 and the second adjusting block 5, that is, the relative sliding directions of the height adjustment rod 3, the first adjusting block 4 and the second adjusting block 5 are all perpendicular to each other, forming relative sliding directions in the three directions of the XYZ axis. Among them, a sliding groove is provided on the second connecting block 6, and the end portion of the first adjusting block 4 close to the second connecting block 6 extends into the sliding groove, thereby slidingly cooperating with the second connecting block 6.

[0069] When you need to adjust the left and right position of the protective gas support cover 1, refer to Fig.12 , loosen the bolts (preferably two) at the bottom of the second connecting block 6 connected to the first adjusting block 4, and then slide the first adjusting block 4 left and right in the sliding groove to adjust the left and right position of the protective gas support cover 1; after adjustment, re-tighten the bolts at the bottom of the second connecting block 6 connected to the first adjusting block 4, thereby completing the re-fixation of the two and the adjustment of the left and right position of the protective gas support cover 1.

[0070] According to one embodiment of the present invention, the top end of the protective gas support cover 1 is bolted and rotatably mounted with a first connecting block 2. In this embodiment, referring to Figure 1 The length direction of the first connection block 2 is the same as the length direction of the protective gas support cover 1 and is arranged in line with the center line of the protective gas support cover 1. The end of the first connection block 2 is rotatably connected to the bottom end of the height adjustment rod 3 by bolts, preferably, the end of the first connection block 2 away from the first jet mechanism is rotatably connected to the bottom end of the height adjustment rod 3 by bolts, and the height adjustment rod 3 is installed on the top of the protective gas support cover 1 through the first connection block 2.

[0071] By providing the first connecting block 2, the degree of freedom between the height adjustment rod 3 and the protective gas support cover 1 can be increased, so that the adjustment of the two can be more flexible.

[0072] According to one embodiment of the present invention, the height adjustment rod 3 is a multi-prism structure, preferably a quadrangular prism structure with two adjacent sides being perpendicular to each other. Figure 1 The height adjustment rod 3 may be a rectangular parallelepiped structure, so that the height adjustment rod 3 can play a limiting role in the second adjustment block 5, preventing the height adjustment rod 3 from rotating in the second adjustment block 5. When adjusting the height of the shielding gas support hood 1, the height adjustment rod 3 with a rectangular parallelepiped structure can prevent the shielding gas support hood 1 from rotating when adjusting the height, thereby ensuring that the shielding gas support hood 1 and the weld of the workpiece 9 are always in a parallel state, further ensuring the smooth progress of the welding work.

[0073] According to one embodiment of the present invention, the first jet mechanism includes an oblique air outlet tunnel 14 opened at the bottom end of the protective gas support cover 1, and the oblique air outlet tunnel 14 is located between the light outlet point of the laser welding gun and the second jet mechanism. Preferably, the angle between the bottom end of the oblique air outlet tunnel 14 and the bottom end of the protective gas support cover 1 is or is substantially 45°, preferably 45°. The bottom end of the oblique air outlet tunnel 14 is arranged corresponding to the weld of the workpiece 9, and the first air pipe 7 is installed on the protective gas support cover 1, and the top end of the oblique air outlet tunnel 14 is connected to one end of the first air pipe 7.

[0074] In this embodiment, refer to Figure 4 and Figure 8 The oblique air outlet tunnel 14 is opened on the center line of the length direction of the protective gas support cover 1, and the bottom end of the oblique air outlet tunnel 14 is located at the angle between the bottom end and the side end of the protective gas support cover 1. The inclination angle of the oblique air outlet tunnel 14 is also set along the center line of the length direction of the protective gas support cover 1. The diameter of the bottom opening of the oblique air outlet tunnel 14 can be preferably 4mm. The first air pipe 7 can be vertically inserted into the top of the protective gas support cover 1 and coaxially arranged with the top of the oblique air outlet tunnel 14, and the bottom end of the first air pipe 7 is connected to the top of the oblique air outlet tunnel 14. Among them, the connection method between the first air pipe 7 and the protective gas support cover 1 can be a fixed connection and a detachable connection known in the art, such as connecting the first air pipe 7 to the protective gas support cover 1 by a glue-like substance, which is not particularly limited here.

[0075] When the first air jet mechanism is required to jet the molten metal at the weld of the workpiece 9 to prevent oxidation, the top end of the first air pipe 7 is connected to an external air blowing device, so that air can be blown at an angle of 45° through the oblique air outlet hole 14 onto the molten metal at the weld of the workpiece 9 to complete the anti-oxidation work of the molten metal. The air blowing device is a prior art known in the art and will not be described in detail herein.

[0076] According to one embodiment of the present invention, the second jet mechanism includes a third air pipe 11 installed in the protective gas support cover 1, and a second air pipe 8 is installed on the protective gas support cover 1, and one end of the second air pipe 8 is connected to one end of the third air pipe 11. A ventilation groove is opened at the bottom end of the protective gas support cover 1, and the oblique air outlet hole 14 is located between the ventilation groove and the light outlet point of the laser welding gun. The top of the ventilation groove is connected to the third air pipe 11, and a first orifice plate 10 (refer to Figure 6 ), the first orifice plate 10 is arranged corresponding to the weld of the workpiece 9. The ventilation groove and the third air pipe 11 are independently arranged with the oblique air outlet tunnel 14, that is, the ventilation groove and the third air pipe 11 are not connected with the oblique air outlet tunnel 14.

[0077] In this embodiment, refer to Figure 4 , Figure 6 , Figure 8 or Fig.11The length direction of the third air pipe 11 is located on the center line of the length direction of the protective air support cover 1 and is arranged in the horizontal direction. The second air pipe 8 is plugged into the end of the protective air support cover 1 away from the oblique air outlet tunnel 14 and is coaxially arranged with the third air pipe 11. The end of the second air pipe 8 located inside the protective air support cover 1 is connected to the third air pipe 11. The first orifice plate 10 is fixedly mounted on the inner wall of the bottom end of the ventilation groove in the horizontal direction. The fixed connection method can be various methods known in the art, such as fixed connection by welding, etc. The aperture of the hole on the first orifice plate 10 can preferably be 1 mm.

[0078] When the second air jet mechanism is needed to jet the high-temperature metal at the weld of the workpiece 9 to prevent it from being oxidized, the end of the second air pipe 8 outside the protective gas support cover 1 is connected to an external air blowing device, so that air can be blown onto the high-temperature metal at the weld of the workpiece 9 through the ventilation groove and the first orifice plate 10 to complete the anti-oxidation work of the high-temperature metal. Among them, the holes on the first orifice plate 10 can play a role in balancing the air blown out of the ventilation groove to the outside of the protective gas support cover 1, thereby improving the anti-oxidation effect on the high-temperature metal.

[0079] According to one embodiment of the present invention, the third air pipe 11 is located at the top of the ventilation groove, and a second orifice plate 13 is provided between the third air pipe 11 and the first orifice plate 10, and the inner wall of the ventilation groove is fixedly connected to the side wall of the second orifice plate 13. Figure 4 The second orifice plate 13 is also arranged at the top of the ventilation groove and is located below the third air pipe 11. The fixed connection method can be welding or other methods known in the art, which is not particularly limited here.

[0080] In this embodiment, refer to Figure 4 The diameter of the hole on the second orifice plate 13 is also preferably 1 mm. Fig.10 The second orifice plate 13 directly below the third air pipe 11 can be bent upward at both ends, so that it can wrap the lower part of the third air pipe 11. Through the arrangement of the first orifice plate 10 and the second orifice plate 13, the air blown out of the protective air support cover 1 can be flow-balanced twice, so that the flow-balance effect is better, and the anti-oxidation effect on high-temperature metals can be further improved.

[0081] According to one embodiment of the present invention, one end of the third air pipe 11 close to the oblique wind outlet tunnel 14 is connected to a plurality of branch air pipes 12. Figure 8, there are two branch air pipes 12, and they are symmetrically arranged on both sides of the oblique air outlet tunnel 14. The two branch air pipes 12 form a Y-shaped structure with the third air pipe 11, and the branch air pipes 12 are independently arranged with the oblique air outlet tunnel 14, that is, the branch air pipes 12 are not connected with the oblique air outlet tunnel 14. The third air pipe 11 and the branch air pipe 12 are both provided with a number of ventilation holes corresponding to the holes on the second orifice plate 13, and the diameter of the ventilation holes is preferably 1mm. A small tube (not shown in the figure) is arranged between each hole on the second orifice plate 13 and the corresponding ventilation hole, and the two ends of each small tube are respectively fixedly connected to the second orifice plate 13 and the corresponding ventilation hole, and the fixed connection method can be welding or other methods known in the art. The third air pipe 11 and the branch air pipe 12 are connected to the ventilation groove through the ventilation holes and the small tubes.

[0082] In this embodiment, refer to Fig.10 , only the portion of the second orifice plate 13 directly below the third air pipe 11 will be bent, while the portion of the second orifice plate 13 directly below the branch air pipe 12 will not be bent.

[0083] Since the third air pipe 11 is horizontal and arranged in the same line with the oblique air outlet tunnel 14, and the third air pipe 11 cannot be connected to the oblique air outlet tunnel 14, the end of the third air pipe 11 away from the second air pipe 8 can only be located on one side of the oblique air outlet tunnel 14, thereby limiting the length of the third air pipe 11 in the protective air support cover 1; and through the arrangement of the branch air pipe 12, the third air pipe 11 can be extended in disguised form in the protective air support cover 1 without being connected to the oblique air outlet tunnel 14 (that is, the branch air pipe 12 makes up for the length of the third air pipe 11 in the protective air support cover 1), thereby increasing the air outlet volume of the third air pipe 11 in the protective air support cover 1.

[0084] In addition, the setting of the vents can achieve one equalization of the air blown out of the third air pipe 11, plus two equalizations of the first orifice plate 10 and the second orifice plate 13, a total of three equalizations of the air can be achieved, thereby further improving the equalization effect of the air, and further improving the anti-oxidation effect on high-temperature metals. Among them, through the setting of the small tube, the air blown out of the third air pipe 11 and the second orifice plate 13 can be guided to increase the air blowing efficiency.

[0085] The present invention also provides a method for welding using a gas-shielded laser welding device in a niobium alloy atmospheric environment, the method being as follows:

[0086] First, install the laser welding gun on the second connecting block 6 of the device, and set the light output point of the laser welding gun directly downward; splice the left and right workpieces 9 to be welded and splice the welds to be welded, and place the welds of the left and right workpieces 9 directly below the light output point of the laser welding gun; after placement, install the device on the robot.

[0087] Then, the position of the protective gas support cover 1 needs to be adjusted, preferably, it is divided into the following four steps:

[0088] The first step is to loosen the bolts at the connection between the protective gas support cover 1 and the first connecting block 2, and the first connecting block 2 and the height adjustment rod 3 in turn to adjust the angle of the protective gas support cover 1. After adjusting it to be level with the workpiece 9, tighten the bolts at the connection between the protective gas support cover 1 and the first connecting block 2, and the first connecting block 2 and the height adjustment rod 3 in turn to complete the adjustment of the horizontality of the protective gas support cover 1.

[0089] In the second step, a robot is used to adjust the distance and position between the bottom end of the welding head of the laser welding gun and the weld at the top end of the workpiece 9 so that the distance and position are at a suitable working distance and position, and the vertical distance between the bottom end of the welding head of the laser welding gun and the top end of the workpiece 9 is adjusted to be greater than 2.5 mm.

[0090] Then, loosen the bolts at the connection between the second adjusting block 5 and the height adjusting rod 3. After loosening, pull the height adjusting rod 3 upward to move the height adjusting rod 3 upward in the second adjusting block 5. At this time, the upward movement of the height adjusting rod 3 will cause the protective gas support cover 1 to move upward at the same time, and the moving distance will be greater than 2.5 mm, preferably much greater than 2.5 mm. After the movement, retighten the bolts at the connection between the second adjusting block 5 and the height adjusting rod 3.

[0091] Then, according to the actual welding needs, the robot is used to drive the welding head of the laser welding gun to drop 1.5mm-2.5mm. Since the distance between the bottom end of the welding head of the laser welding gun and the top end of the workpiece 9, and the distance between the bottom end of the protective gas support cover 1 and the top end of the workpiece 9 are both greater than 2.5mm, during the descent process, the bottom end of the welding head of the laser welding gun and the bottom end of the protective gas support cover 1 will not collide with the workpiece 9; after the descent is completed, loosen the bolts at the connection between the second adjustment block 5 and the height adjustment rod 3, and move the height adjustment rod 3 downward until the bottom end of the protective gas support cover 1 fits the surface of the workpiece 9 and stops, and then tighten the bolts at the connection between the second adjustment block 5 and the height adjustment rod 3 again after stopping.

[0092] Finally, the robot is used to adjust the welding head of the laser welding gun to restore it to its original position (i.e., the position before it dropped 1.5mm-2.5mm). At this time, the distance between the bottom end of the protective gas support cover 1 and the top end of the workpiece 9 is 1.5mm-2.5mm, thereby completing the vertical adjustment of the protective gas support cover 1.

[0093] The third step is to loosen the bolts at the connection between the first adjustment block 4 and the second connection block 6, and adjust the position of the protective gas support cover 1 laterally so that the first jet mechanism and the second jet mechanism are centered with the weld of the workpiece 9. After the adjustment, re-tighten the bolts at the connection between the first adjustment block 4 and the second connection block 6 to complete the adjustment of the centering of the protective gas support cover 1.

[0094] The fourth step is to loosen the bolts at the connection between the second adjustment block 5 and the first adjustment block 4, and adjust the position of the protective gas support cover 1 along the sliding direction of the second adjustment block 5 on the first adjustment block 4, so as to adjust the distance between the bottom end of the oblique air outlet tunnel 14 and the light outlet point of the laser welding gun. The adjustment range of the distance between the bottom end of the oblique air outlet tunnel 14 and the light outlet point of the laser welding gun is 3mm-5mm.

[0095] Then, in this embodiment, the thickness of the workpiece 9 is 1mm-2mm, which is suitable for large spot welding. Therefore, the focus height of the laser welding gun light point can be adjusted, and the focus can be adjusted to be located above the weld of the workpiece 9, that is, the positive defocus method (refer to Fig.13 ), the distance between the focus and the weld of the workpiece 9 (i.e., the defocus amount) is in the range of 3mm-6mm. After adjustment, the ends of the first air pipe 7 and the second air pipe 8 outside the protective gas support cover 1 are connected to the external blowing device, and the external blowing device is started, so that air can be blown to the weld of the workpiece 9 through the first jet mechanism and the second jet mechanism respectively.

[0096] Finally, the laser welding gun is started, and the robot is used to move the device along the weld direction of the workpiece 9, thereby welding the workpiece 9. During the welding process, the robot can be used to swing the light outlet of the laser welding gun at a frequency of 80 Hz and an amplitude of 0.6 mm-1 mm, that is, the weld of the workpiece 9 is welded by laser swing welding, thereby adapting to the 0.2 mm weld gap and 0.2 mm weld misalignment at the weld of the workpiece 9. In this embodiment, reference Fig.14 The oscillation mode of the laser oscillating welding can be preferably circular oscillation, thereby further adapting to the gap and misalignment at the weld of the workpiece 9, and better ensuring a good welding effect.

[0097] The above-mentioned embodiments of the present invention can be combined with each other and have corresponding technical effects.

[0098] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas shielded laser welding device for niobium alloy in atmospheric environment, characterized in that: It includes a protective gas support cover, an adjustment mechanism, a first jet mechanism and a second jet mechanism, wherein: A workpiece to be welded is placed below the protective gas support cover, and the weld of the workpiece is arranged corresponding to the protective gas support cover; One end of the adjustment mechanism is mounted on the protective gas support cover, and the other end of the adjustment mechanism is mounted with a laser welding gun of the laser welding device, wherein a light emitting point of the laser welding gun is arranged corresponding to a weld seam of the workpiece; The first jet mechanism and the second jet mechanism are both installed in the protective gas support cover, and the first jet mechanism and the second jet mechanism are both arranged corresponding to the weld of the workpiece, the first jet mechanism is located between the light outlet point of the laser welding gun and the second jet mechanism, the first jet mechanism is used to protect the molten metal during the welding process of the workpiece, and the second jet mechanism is used to protect the weld metal during the welding process of the workpiece; The first jet mechanism includes an oblique air outlet tunnel provided at the bottom end of the protective gas support cover, the oblique air outlet tunnel is located between the light outlet point of the laser welding gun and the second jet mechanism; the bottom end of the oblique air outlet tunnel is arranged corresponding to the weld of the workpiece, a first air pipe is installed on the protective gas support cover, and the top end of the oblique air outlet tunnel is connected to the first air pipe; The second jet mechanism comprises a third air pipe installed in the protective gas support cover, a second air pipe is installed on the protective gas support cover, one end of the second air pipe is connected with one end of the third air pipe, a ventilation groove is provided at the bottom end of the protective gas support cover, the oblique air outlet tunnel is located between the ventilation groove and the light outlet point of the laser welding gun, the top of the ventilation groove is connected with the third air pipe, a first orifice plate is fixedly installed on the inner wall of the bottom end of the ventilation groove, the first orifice plate is arranged corresponding to the weld of the workpiece, and the ventilation groove and the third air pipe are independently arranged from the oblique air outlet tunnel; The third air pipe is located at the top of the ventilation groove, and a second orifice plate is arranged between the third air pipe and the first orifice plate, and the inner wall of the ventilation groove is fixedly connected to the side wall of the second orifice plate; One end of the third air pipe close to the oblique air outlet tunnel is connected with a plurality of branch air pipes, and the branch air pipes are independently arranged from the oblique air outlet tunnel; the third air pipe and the branch air pipe are both provided with a plurality of ventilation holes corresponding to the holes on the second orifice plate one by one, a small tube is arranged between each hole on the second orifice plate and the corresponding ventilation hole, and both ends of each small tube are respectively fixedly connected to the second orifice plate and the corresponding ventilation hole; the third air pipe and the branch air pipe are both connected to the ventilation groove through the ventilation holes and the small tubes; The second orifice plate is also arranged at the top of the ventilation groove and below the third air pipe; Both ends of the second orifice plate below the third air pipe are bent upwards, thereby wrapping the lower part of the third air pipe.

2. The gas shielded laser welding device for niobium alloy in atmospheric environment according to claim 1, characterized in that: The adjusting mechanism comprises a height adjusting rod, which is arranged vertically, and the bottom end of the height adjusting rod is mounted on the top end of the protective gas support cover, and a second adjusting block is slidably mounted on the top of the height adjusting rod in a bolt-fixed manner, and the relative sliding direction between the second adjusting block and the height adjusting rod is arranged along the length direction of the height adjusting rod; a first adjusting block is slidably mounted on the second adjusting block in a bolt-fixed manner, and the relative sliding direction between the first adjusting block and the second adjusting block is arranged horizontally and along the direction in which the first jet mechanism approaches or moves away from the light emitting point of the laser welding gun; a second connecting block is slidably mounted on the first adjusting block in a bolt-fixed manner, and the relative sliding direction between the second connecting block and the first adjusting block is arranged horizontally and perpendicular to the relative sliding direction between the first adjusting block and the second adjusting block, and the laser welding gun of the laser welding device is detachably mounted on the end of the second connecting block.

3. The gas shielded laser welding device for niobium alloy in atmospheric environment according to claim 2, characterized in that: A first connecting block is rotatably mounted on the top of the protective gas support cover, and a terminal end of the first connecting block is rotatably connected to a bottom end of the height adjustment rod, and the height adjustment rod is mounted on the top of the protective gas support cover through the first connecting block.

4. The gas shielded laser welding device for niobium alloy in atmospheric environment according to claim 2, characterized in that: The height adjustment rod is a multi-prism structure.

5. The gas shielded laser welding device for niobium alloy in atmospheric environment according to claim 1, characterized in that: The included angle between the bottom end of the oblique air outlet tunnel and the bottom end of the protective air support cover is 45°.

6. A welding method of a niobium alloy gas shielded laser welding device in an atmospheric environment, characterized in that: The method comprises the steps of using the device according to any one of claims 1 to 5 to perform welding, comprising: S1. Place the weld of the workpiece below the light-emitting point of the laser welding gun; S2. Vertically adjust the protective gas support cover so that the distance between its bottom and the top of the workpiece is 1.5mm-2.5mm; S3, the protective gas support cover in step S2 is adjusted horizontally so that the first jet mechanism and the second jet mechanism are centered with the weld of the workpiece, and the distance between the bottom end of the oblique air outlet tunnel and the light outlet point of the laser welding gun is 3 mm-5 mm; S4. Adjust the focal height of the laser welding gun so that the distance between it and the weld of the workpiece is 3mm-6mm; S5, connecting the first air pipe and the second air pipe to an external blower and starting them; S6. Start the laser welding gun and move the laser welding device along the weld direction of the workpiece. Use the robot to swing the light outlet of the laser welding gun at a frequency of 80 Hz and an amplitude of 0.6 mm-1 mm, that is, use laser swing welding to weld the weld of the workpiece, thereby adapting to a weld gap of 0.2 mm and a weld misalignment of 0.2 mm at the weld of the workpiece.

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