A gas protection device for laser welding of titanium alloy ring weld

Abstract

The utility model belongs to titanium alloy laser welding field, concretely relates to a kind of welding gas protection device for annular weld between titanium alloy tubular part and joint. A kind of gas protection device for titanium alloy annular weld laser welding, the gas protection device includes atmosphere protection gas system, coaxial protection gas system;Atmosphere protector system includes cavity, atmosphere protection gas inlet joint, cavity inner side is used to place the part to be welded, inner side is the copper filter sheet manufactured by powder metallurgy method, the copper filter sheet is arc, the through-hole for installing atmosphere protection gas inlet is set on cavity outer side, atmosphere protection gas inlet joint is interference fit with atmosphere protection gas inlet;High-purity argon enters from atmosphere protection gas inlet joint, coaxial protection gas inlet joint respectively.The utility model can effectively complete the laser welding of the rod parts connected by aircraft engine under atmospheric conditions, without manual welding intervention, reduce production cost, improve production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of titanium alloy laser welding, specifically relating to a gas protection device for welding the circumferential weld between a titanium alloy tubular part and a joint. Background Technology

[0002] With the rapid development of aviation technology, aircraft design increasingly considers the requirements for high maneuverability, high reliability, and long service life. The application of titanium alloys in aircraft can fully meet these design requirements. Aircraft often use rod-like parts to secure engines, and these parts typically consist of joints and connecting rods. Laser welding technology, as an advanced high-energy beam joining technology, features high automation and minimal thermal deformation, enabling effective connections between titanium alloy joints and connecting rods used in aviation. However, titanium alloys are prone to oxidation during welding, which severely affects weld formation and strength. Therefore, ensuring the titanium alloy is isolated from oxygen at high temperatures is an effective means of preventing oxidation.

[0003] Traditional circumferential welds on titanium alloys are often performed in a vacuum argon-filled chamber, which requires a large amount of argon gas to fill the chamber, resulting in high costs and hindering automated welding. The use of a drag shield as a protective device is already widely adopted for straight welds on titanium alloys, and its protective effect has been widely recognized in the industry. To reduce manufacturing costs and improve production efficiency, there is an urgent need to develop a curved drag shield for protecting titanium alloy circumferential welds in an atmospheric environment, preventing oxidation and achieving good weld formation. Summary of the Invention

[0004] The purpose of this invention is to provide a gas protection device for laser welding of titanium alloy circumferential welds, which can improve the production efficiency of welding between support rods and joints in the aerospace field and reduce manufacturing costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a gas protection device for laser welding of titanium alloy annular welds, the gas protection device comprising an atmosphere protection gas system and a coaxial protection gas system; the atmosphere protection gas system comprises a cavity and an atmosphere protection gas inlet connector, the inner side of the cavity is used to place the part to be welded, the inner side is a copper filter manufactured by powder metallurgy, the copper filter is arc-shaped, and a through hole for installing the atmosphere protection gas inlet is opened on the outer side of the cavity, the atmosphere protection gas inlet connector is interference-fitted with the atmosphere protection gas inlet; the coaxial protection gas system comprises a coaxial protection gas inlet connector and a coaxial protection gas inlet, a through hole for installing the coaxial protection gas inlet is opened on the top of the cavity, the coaxial protection gas inlet connector is interference-fitted with one end of the coaxial protection gas inlet; high-purity argon gas enters from the atmosphere protection gas inlet connector and the coaxial protection gas inlet connector respectively.

[0006] Preferably, the outer surface of the cavity is an arc-shaped plate, coaxial with the inner surface; the two ends of the inner and outer surfaces are sealed with semi-circular plates, and the two sides of the inner and outer surfaces are sealed with square plates.

[0007] Preferably, the curved plate, semi-circular plate, and square plate are all made of stainless steel.

[0008] Preferably, when the size of the part to be welded is too small, a semi-circular rubber sheet can be pasted at the position of the semi-circular plate to reduce the leakage of the protective atmosphere and improve the protective effect.

[0009] Furthermore, it also includes a copper nozzle, which is interference-fitted with the other end of the coaxial protective gas inlet; and the notch of the copper nozzle faces outward.

[0010] Preferably, the copper filter has a powder mesh size of 40 to 60 mesh and a thickness of 2 to 4 mm.

[0011] Preferably, the part to be welded is positioned directly below the coaxial protective gas.

[0012] Compared with the prior art, this utility model has the following advantages: it can effectively complete the laser welding of rod-like parts for connecting aircraft engines under atmospheric conditions, without the need for manual welding, thereby reducing production costs and improving production efficiency. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0014] Figure 2 This is a cross-sectional view of an embodiment of the present utility model;

[0015] Figure 3 This is an exploded view of an embodiment of this utility model;

[0016] Figure 4 This is a schematic diagram of the clamping of Embodiment 1 of this utility model (welding of cylindrical joints).

[0017] Figure 5 This is a diagram showing the connection between the fork-shaped connector and the support rod in Embodiment 2 of this utility model;

[0018] Figure 6 This is a schematic diagram of the clamping of Embodiment 2 of this utility model (welding of fork-shaped joints);

[0019] Figure 1-3In the middle, 2-welding protection device; 6-coaxial shielding gas; 7-atmosphere shielding gas; 201-lower square side plate; 202-upper left square side plate; 203-upper right square side plate; 204-left semi-circular side plate; 205-right semi-circular side plate; 211-outer arc-shaped plate; 212-inner arc-shaped plate; 221-atmosphere shielding gas inlet; 222-coaxial shielding gas inlet; 223-copper nozzle; 231-atmosphere shielding gas inlet connector; 232-coaxial shielding gas inlet connector;

[0020] Figure 4 In the diagram, 1-processing laser beam; 2-welding protection device; 3-part to be welded; 4-weld; 301-cylindrical joint; 302-support rod;

[0021] Figure 5-6 In the diagram, 1-processing laser beam; 2-welding protection device; 5-welding wire; 302-support rod; 303-fork joint; 401-welded area; 402-area to be welded. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-3 The present invention provides a further description of an embodiment: a gas protection device for laser welding of titanium alloy circumferential welds, the gas protection device comprising an atmosphere protection gas system and a coaxial protection gas system;

[0023] The protective atmosphere system is formed by welding square stainless steel plates, semi-circular stainless steel plates, and arc-shaped stainless steel plates to create a cavity, wherein, as shown... Figure 3 As shown, the square stainless steel plate includes a lower square side plate 201, an upper left square side plate 202, and an upper right square side plate 203; the semi-circular stainless steel plate includes a left semi-circular side plate 204 and a right semi-circular side plate 205; and the arc-shaped stainless steel plate includes an outer arc-shaped plate 211. An inner arc-shaped plate 212, made by powder metallurgy, is embedded at the bottom of the cavity. A circular hole is opened on the outer arc-shaped plate 211 for welding a protective atmosphere gas inlet 221. The other end of the protective atmosphere gas inlet 221 is fitted with an interference fit protective atmosphere gas inlet connector 231.

[0024] The coaxial protective gas system consists of a copper nozzle 223, a coaxial protective gas inlet 222, and a coaxial protective gas inlet connector 232. The copper nozzle 223 is made of pure copper. The coaxial protective gas inlet 222 is welded to an opening at the top of the cavity. The copper nozzle 223 and the coaxial protective gas inlet 222 are press-fitted at one end with the notch facing outward. The coaxial protective gas inlet connector 232 is press-fitted with the coaxial protective gas inlet 222.

[0025] In a preferred embodiment of this invention, after assembling according to the illustrated orientation, all stainless steel components are welded together. The inner arc-shaped plate 212 is a copper filter sheet manufactured by powder metallurgy, with a powder mesh size of 40 to 60 mesh and a thickness of 2 mm to 4 mm, and is embedded in the inner ring of the welded stainless steel cavity. If the stainless steel cavity deforms excessively after welding, resulting in a loose fit between the inner arc-shaped plate and the stainless steel cavity, high-temperature adhesive is required to fill the gap.

[0026] The assembled titanium alloy circumferential weld protection device 2 is as follows Figure 2 As shown, the coaxial protective gas 6 is made of high-purity argon, which enters through the coaxial protective gas inlet connector 232 and passes through the coaxial protective gas inlet port 222 and the copper nozzle 223. The atmosphere protective gas 7 is also made of high-purity argon, which enters through the atmosphere protective gas inlet connector 231 and passes through the atmosphere protective gas inlet port 221 into the cavity. The atmosphere protective gas is evenly distributed in the cavity by being blocked by the inner arc plate 212. After the cavity pressure increases, the atmosphere protective gas passes through the inner arc plate 212, forming a protective atmosphere that isolates air in the vicinity. Example 1

[0027] like Figure 4 As shown, the cylindrical part to be welded is clamped in the welding protection device 2. After the cylindrical joint and the support rod are assembled, it is placed in the protection range of the atmosphere shielding gas system. The position to be welded is placed directly below the coaxial shielding gas. The position of the laser head is adjusted so that the laser is incident at an angle. The atmosphere shielding gas and the coaxial shielding gas are introduced. The part to be welded is rotated in the direction of the gas protection device. The laser is turned on to complete the welding.

[0028] Its usage method specifically includes the following steps:

[0029] 1. Place the part to be welded 3 in the inner arc position of the welding protection device 2, ensuring that the central axis of the part to be welded 3 is completely aligned with the central axis of the welding protection device. The part to be welded 3 can be fixed on a rotary table equipped with a three-jaw chuck. The welding protection device 2 can be fixed using a magnetic base with a connecting rod, or it can be fixed to the laser head using a connecting rod. Move the part to be welded 3 to keep the plane of the weld seam 4 aligned with the axis of the coaxial shielding gas inlet.

[0030] Specifically, the distance between weld 4 and welding protection device 2 should be controlled between 3 mm and 8 mm. If the distance is too large, semi-circular rubber sheets can be installed on the left semi-circular side plate 204 and the right semi-circular side plate 205 of welding protection device 2 to fill the excessive gap.

[0031] 2. Deflect the laser head and use an indicator red light or a coaxial CCD display to position the laser welding position. The positioning point is the intersection of the axis of weld 4 and the coaxial shielding gas inlet 222 of the welding protection device 2. The processing laser beam 1 needs to be at a certain angle to the axis of the gas inlet to avoid the processing laser beam 1 being blocked by the welding protection device 2;

[0032] The included angle should not be too large, otherwise too much laser energy will be reflected, the energy utilization rate will be too low, and the melting depth will be too shallow.

[0033] 3. Set the rotation direction of the rotary table so that the part to be welded 3 rotates towards the welding protection device 2. Adjust the rotation speed of the part to be welded 3 to a suitable welding speed, calculate the time T1 for the part to be welded 3 to rotate one revolution, and set the laser emission time T2 so that T2>T1 to ensure that the arc start and arc end positions have sufficient overlap length;

[0034] 4. Introduce high-purity argon gas through the coaxial protective gas inlet connector 232 and adjust the argon gas flow rate to a suitable level. Introduce high-purity argon gas through the protective gas inlet connector 231 and adjust the argon gas pressure to a suitable level.

[0035] 5. Turn on the rotary table to rotate the part 3 to be welded. After the rotation speed stabilizes, turn on the laser and start the processing laser beam 1. After the laser stops, the welding of the part 3 to be welded is completed; turn off the rotary table. Example 2

[0036] like Figure 5-6 As shown, the fork-shaped part to be welded is clamped in the welding protection device 2. After the fork-shaped joint and the support rod are assembled, they are first positioned by spot welding. The shielding gas device is installed in the forked area of ​​the fork-shaped joint. The area to be welded is placed directly below the coaxial shielding gas. The laser head position is adjusted so that the laser is incident at an angle. The ambient shielding gas and the coaxial shielding gas are introduced. The part to be welded is rotated towards the gas protection device while the laser is turned on. When the fork-shaped joint is about to block the laser, the laser is turned off and the rotation of the part is stopped. The part to be welded is rotated to the initial position, and the laser head and the shielding gas device are moved to a symmetrical position. The operation of simultaneously turning on the laser and rotating the part is repeated to complete the welding.

[0037] Its usage method specifically includes the following steps:

[0038] 1. The connection method between the fork-shaped joint and the support rod is as follows: Figure 5 As shown, after the fork-shaped joint 303 and the support rod 302 are assembled, their relative positions are fixed by spot welding to form the part to be welded 3. The welding protection device 2 is installed on the plane where the weld seam 4 is located. A cross-sectional view of the part to be welded 3 is taken on the plane where the weld seam 4 is located. The relative positions of the part to be welded 3 and the welding protection device are shown in the figure. Figure 6 As shown; the other end of the part 3 to be welded is fixed on a rotary table equipped with a three-jaw chuck;

[0039] 2. Deflect the laser head using an indicator red light or a coaxial CCD display to position the laser welding area. The processing laser beam 1 needs to be at a certain angle to the air inlet axis to prevent it from being blocked by the welding protection device 2 or the fork-shaped connector 303. The incident direction of the laser beam is as follows: Figure 6 As shown;

[0040] 3. Set the direction of rotation of the rotary table to drive the part to be welded 3 as follows: Figure 6 As shown in Figure (a), the rotational speed of the rotary table is set, and the rotation angle of the rotary table is set to θ1, as follows. Figure 6 As shown in Figure (b);

[0041] 4. Introduce high-purity argon gas through the coaxial protective gas inlet connector 232 and adjust the argon gas flow rate to a suitable level. Introduce high-purity argon gas through the protective gas inlet connector 231 and adjust the argon gas pressure to a suitable level.

[0042] 5. Turn on the processing laser beam 1, and simultaneously open the rotary table to rotate the part 3 to be welded. (Example:) Figure 6 As shown in Figure (b), after the part to be welded 3 rotates by θ1, the processing laser beam 1 is turned off to prevent the processing laser beam 1 from irradiating the fork-shaped joint 303 and damaging the part. The angle of the welded area 401 reaches θ1, and it remains there for a sufficient time to ensure that the weld is not oxidized before cooling.

[0043] 6. Rotate the rotary table to position the fork-shaped connector 303 as shown. Figure 6 In the position shown in Figure (c), control the robot to swing the laser head to a suitable position (facing the area to be welded 402), so that the processing laser beam 1 swings to a position symmetrical to the plane of symmetry of the fork-shaped joint 303. Position the welding protection device 2 symmetrical to the plane of symmetry of the fork-shaped joint 303, as shown in Figure (c). Figure 6 As shown in Figure (c);

[0044] 7. Set the rotation direction of the rotary table to the opposite direction and the rotation angle to θ2, ensuring that θ1+θ2>360°. To avoid welding craters at the tail of the weld, fill with welding wire 5.

[0045] 8. Turn on the processing laser beam 1, activate the wire feeding function, and simultaneously turn on the rotary table to rotate the part 3 to be welded. After the rotation angle reaches θ2, stop the wire feeding, turn off the processing laser beam 1, and remove the laser head. After a sufficient period of time, turn off the coaxial shielding gas and ambient shielding gas to complete the welding.

Claims

1. A gas protection device for laser welding of titanium alloy circumferential welds, characterized in that: The gas protection device includes an atmosphere protection gas system and a coaxial protection gas system. The atmosphere protection gas system includes a cavity and an atmosphere protection gas inlet connector. The inner side of the cavity is used to place the parts to be welded, and the inner side is a copper filter sheet manufactured by powder metallurgy. The copper filter sheet is arc-shaped. A through hole for installing the atmosphere protection gas inlet is opened on the outer side of the cavity. The atmosphere protection gas inlet connector is interference-fitted with the atmosphere protection gas inlet. The coaxial protection gas system includes a coaxial protection gas inlet connector and a coaxial protection gas inlet. A through hole for installing the coaxial protection gas inlet is opened on the top of the cavity. The coaxial protection gas inlet connector is interference-fitted with one end of the coaxial protection gas inlet. High-purity argon gas enters from the atmosphere protection gas inlet connector and the coaxial protection gas inlet connector, respectively.

2. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 1, characterized in that: The outer surface of the cavity is an arc-shaped plate, coaxial with the inner surface; the two ends of the inner and outer surfaces are sealed with semi-circular plates, and the two sides of the inner and outer surfaces are sealed with square plates.

3. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 2, characterized in that: The curved, semi-circular, and square plates are all made of stainless steel.

4. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 2 or 3, characterized in that: When the size of the part to be welded is too small, attach a semi-circular rubber sheet to the semi-circular plate position.

5. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 1, characterized in that: It also includes a copper nozzle, which is interference-fitted with the other end of the coaxial protective gas inlet; and the notch of the copper nozzle faces outward.

6. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 1, characterized in that: The copper filter sheet has a powder mesh size of 40 to 60 mesh and a thickness of 2 mm to 4 mm.

7. The gas protection device for laser welding of titanium alloy circumferential welds according to claim 1, characterized in that: The part to be welded is positioned directly below the coaxial protective gas.

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