Laser welding device and method for titanium alloy ring-shaped heat sink

Abstract

The application discloses a laser welding device and method for a titanium alloy annular radiator, and the welding device comprises a support beam, a gas cylinder, a robot, a laser calming head, a pressure roller mechanism, a laser visual tracker, an annular radiator, a variable-diameter expanding tool, a pressure roller, a support rod, a pressure roller seat, a moving guide rail and a spring. The welding method comprises the following steps: placing the variable-diameter expanding tool into the annular radiator by reducing the diameter of the variable-diameter expanding tool, adjusting the outer diameter size of the variable-diameter expanding tool so that the annular radiator is tightly attached to the surface of the variable-diameter expanding tool, finding the welding seam position of the corrugated plate through the laser visual tracker, feeding back the position information to the pressure roller mechanism and the robot, pressing the pressure roller mechanism according to the set pressure to ensure that the cylinder body is tightly attached to the corrugated plate, filling argon gas in the back surface, the inner cavity and the front surface of the annular radiator for protection and welding, reducing the variable-diameter expanding tool after all the welding seams are welded, and taking out the annular radiator. The application has high welding efficiency, no inner cavity splashing problem, high and stable welding quality.

Description

Technical Field

[0001] This invention belongs to the field of automated laser welding technology for titanium alloy ring heat sinks, specifically a laser welding device and welding method for titanium alloy ring heat sinks. Background Technology

[0002] The level of titanium alloy application is an important indicator of the sophistication of aircraft materials and the development level of the aviation industry, and is a crucial factor affecting aircraft combat capabilities. In recent years, my country has increased its research and development on the application of high-performance titanium alloys, and significant progress has been made in the manufacturing and application of titanium alloys.

[0003] As an indispensable part of aircraft, ships and other fields, the domestic industry is gradually turning to lightweight and high-strength titanium alloy materials for ring-shaped radiators. However, titanium alloy materials are difficult to process, especially high-temperature titanium alloy materials. They have very low room temperature plasticity, making it difficult to form corrugated plate-type parts. They need to be heated to high temperatures for forming.

[0004] The traditional process for bonding the inner cylinder and corrugated plate of a titanium alloy annular radiator is resistance welding, using high-temperature titanium alloy. High-temperature titanium alloy has high strength, and the low pressure used in the resistance welding process cannot effectively clamp the parts together, resulting in severe spatter within the corrugated plate cavity, making cleaning very difficult. If high pressure is used, due to the low thermal conductivity and high coefficient of linear expansion of titanium alloy, large indentations easily form on the corrugated plate, and the weld appearance quality fails to meet standard requirements. Furthermore, the use of water as a welding shield during resistance welding can lead to water decomposition caused by the high welding temperature, which also affects the weld. Summary of the Invention

[0005] This invention aims to provide a laser welding device and method for titanium alloy annular radiators, solving the problems of low welding efficiency and large internal spatter when using traditional resistance welding processes for titanium alloy annular radiators, improving welding efficiency, eliminating internal spatter during the welding process, and ensuring the welding quality of the corrugated plate and the inner cylinder of the annular radiator.

[0006] To solve the above problems, the present invention adopts the following technical solution: A laser welding apparatus for a titanium alloy annular heat sink, comprising: Support beam, wherein the support beam is a rigid frame; A variable diameter expansion fixture is installed inside a support beam to expand and clamp an annular radiator from the inside out. The outer surface of the variable diameter expansion fixture is a cylindrical surface with a variable diameter. The robot is a welding robot and is located on the outside of the support beam. The robot includes a robotic arm for welding and a laser quenching head is mounted on the robotic arm. The pressure roller mechanism is slidably connected to the support beam and located above the variable-diameter expansion tooling. The sliding direction of the pressure roller mechanism is parallel to the axial direction of the variable-diameter expansion tooling. The pressure roller mechanism mainly consists of a cylinder, a pressure roller seat, a pressure roller, a support rod, and a spring. The pressure roller seat includes a fixed plate and a movable plate arranged in parallel in the upper and lower directions and capable of moving relative to each other. The fixed plate is slidably fitted with the support beam. The movable plate has a support rod mounting hole. The fixed plate and the movable plate have laser welding through holes in the same position. The cylinder is mounted on the fixed plate, and the piston rod of the cylinder passes through the fixed plate and is connected to the moving plate; The surface of the support rod has external threads and annular protrusions. After the support rod passes through the support rod mounting hole of the moving plate, its upper end is assembled with a nut through external threads, and its lower end is rotatably connected to the pressure roller. The spring is sleeved on the support rod, with the upper end of the spring in close contact with the lower end face of the moving plate, and the lower end of the spring in close contact with the annular protrusion end face of the support rod. A laser vision tracker is mounted on the pressure roller seat and is used to transmit weld position information to the robot in real time to control the position of the laser calming head.

[0007] As one solution: Two movable guide rails are installed in parallel on the support beam. The extension direction of the movable guide rails is parallel to the axial direction of the variable diameter expansion tool. The pressure roller seat slides with the movable guide rails through the fixed plate. A guide rod is also provided between the fixed plate and the moving plate. The upper end of the guide rod is fixed to the lower end face of the fixed plate, and the lower end of the guide rod passes through the moving plate.

[0008] As one option, the laser welding apparatus also includes a protective cover for introducing welding shielding gas. The protective cover is disposed between the laser quenching head and the annular heat sink. The protective cover includes a corrugated shell with a corrugated groove at the lower end. The shape and size of the corrugated groove match the crests and troughs of the corrugated plate. A laser beam through hole is opened at the upper end of the corrugated shell, and a ring of anti-flow edge is provided along the circumference of the laser beam through hole. A shielding gas inlet is provided on the side of the corrugated shell.

[0009] As one option, multiple support rods are installed in the support rod mounting holes on the moving plate, and the length of the support rod mounting holes is greater than the sum of the outer diameters of the multiple support rods.

[0010] In one embodiment, the pressure roller is rotatably connected to the lower end of the support rod via a rotating shaft, and the installation positions of the pressure roller include the middle of the lower end of the support rod, the left side of the lower end of the support rod, and the right side of the lower end of the support rod.

[0011] As one embodiment, the variable diameter expansion tooling includes four expansion blocks, with a radial expansion range of 0–25 mm. The radial movement of the expansion blocks is adjustable with a precision of 0.1 mm, and the variable diameter expansion tooling can rotate around its own axis.

[0012] A laser welding method for a titanium alloy annular heat sink, employing the aforementioned laser welding apparatus, includes the following steps: Step 1: Reduce the outer diameter of the variable diameter expansion tool and install the annular heat sink with corrugated plate. Step 2: Adjust the outer diameter of the variable diameter expansion tooling so that the inner surface of the annular radiator is in close contact with the outer surface of the variable diameter expansion tooling; Step 3: Locate the weld seam of the corrugated plate using a laser vision tracker and feed the location information back to the robot; Step 4: Adjust the position of the pressure roller mechanism according to the weld position information fed back by the laser vision tracker, start the cylinder to press down at the set pressure until the pressure roller presses the corrugated plate tightly. The pressing position of the pressure roller is the trough of the corrugated plate, ensuring that the inner cylinder of the annular radiator is tightly attached to the corrugated plate. Step 5: Pour argon gas into the back, inner cavity, and front of the annular radiator for protection, and begin laser welding; Step 6: After all welds are completed, reduce the outer diameter of the reducing expansion tool and remove the annular radiator.

[0013] As one option, in step 1, the corrugated plate overlaps the inner cylinder surface of the annular radiator.

[0014] As one approach, in step 3, the weld position that the laser vision tracker locates is the middle of the trough of the corrugated plate.

[0015] As one possible solution, step 4, adjusting the position of the pressure roller mechanism, includes: Slide the pressure roller seat on the support beam; Adjust the position of the support rod inside the support rod mounting hole; A pressure roller is set at the trough of the corrugated plate corresponding to the weld position. A pressure roller is symmetrically set on the left and right sides of the aforementioned pressure roller, and the two pressure rollers are pressed into the trough of the corrugated plate on the left and right sides of the aforementioned trough.

[0016] Compared with existing technologies, this invention employs laser welding for titanium alloy annular radiators. This method eliminates welding spatter, offers high welding speed, and utilizes pure argon gas for protection during the welding process, resulting in stable weld quality and ensuring the quality of the weld between the corrugated plate and the inner cylinder. Throughout the welding process, pressure rollers are used to firmly press the corrugated plate and inner cylinder together, with the rollers symmetrically positioned about the weld seam. This ensures a tight fit between the corrugated plate and the inner cylinder surface (after pressing, the gap between the corrugated plate and the inner cylinder surface is consistent and has minimal fluctuation), guaranteeing high weld quality. A laser vision tracker is used to acquire weld position information promptly and accurately, ensuring correct welding positioning and allowing for timely correction of weld misalignment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the laser welding device designed in this invention; Figure 2 This is an enlarged view of the pressure roller mechanism in a laser welding device; Figure 3 This is a schematic diagram of the protective cover in a laser welding device; In the diagram: 1-Support beam, 2-Cylinder, 3-Robot, 4-Laser sedation head, 5-Pressure roller mechanism, 6-Laser vision tracker, 7-Annular radiator, 8-Variable diameter expansion tooling, 9-Pressure roller, 10-Support rod, 11-Pressure roller seat, 12-Moving guide rail, 13-Spring, 14-Wave-shaped contoured shell, 15-Argon gas inlet, 16-Laser beam, 17-Anti-flow edge. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 and Figure 2The image shows a laser welding device for a titanium alloy annular radiator designed according to the present invention, comprising a support beam 1, a cylinder 2, a robot 3, a laser quenching head 4, a pressure roller mechanism 5, a laser vision tracker 6, an annular radiator 7, a variable diameter expansion tooling 8, a pressure roller 9, a support rod 10, a pressure roller seat 11, a moving guide rail 12, and a spring 13. Support beam 1 is a rigid frame; variable diameter expansion fixture 8 is installed inside support beam 1 to expand and clamp the annular radiator 7 from the inside out. The outer surface of variable diameter expansion fixture 8 is a cylindrical surface with a variable diameter; robot 3 is a welding robot and is set outside support beam 1. Robot 3 includes a robotic arm for welding, and a laser shaving head 4 is installed on the robotic arm; pressure roller mechanism 5 is slidably connected to support beam 1 and located above variable diameter expansion fixture 8. The sliding direction of pressure roller mechanism 5 is parallel to the axial direction of variable diameter expansion fixture 8. Pressure roller mechanism 5 is mainly composed of cylinder 2, pressure roller seat 11, pressure roller 9, support rod 10 and spring 13. Among them, wheel seat 11 includes a fixed plate and a moving plate arranged parallel to each other in the upper and lower directions and can move relative to each other. The fixed plate is slidably fitted with support beam 1. The moving plate has a support rod mounting hole. The fixed plate and the moving plate have laser welding through holes in the same position. The laser beam generated by head 4 can be projected onto the surface of the corrugated plate through the through hole to achieve welding between the corrugated plate and the inner cylinder; cylinder 2 is mounted on the fixed plate, and the piston rod of cylinder 2 passes through the fixed plate and is connected to the moving plate; the surface of the support rod 10 has external threads and annular protrusions. After the support rod 10 passes through the support rod mounting hole of the moving plate, its upper end is assembled with a nut through external threads, and its lower end is rotatably connected to the pressure roller 9; spring 13 is sleeved on the support rod 10, and the upper end of spring 13 is close to the lower end face of the moving plate, and the lower end of spring 13 is close to the annular protrusion end face of the support rod 13. Spring 13 is selected to achieve clamping between the corrugated plate and the inner cylinder. The pressure of spring 13 is 0~500KN, and the gap between the corrugated plate and the inner cylinder after clamping is controlled within 0.3mm; laser vision tracker 6 is mounted on the pressure roller seat 11 and is used to transmit the weld position information to the robot 3 in real time to control the position of the laser calming head 4.

[0020] Two movable guide rails 12 are installed parallel to each other on the support beam 1. The extension direction of the movable guide rails 12 is parallel to the axial direction of the variable diameter expansion tooling 8. The pressure roller seat 11 is slidably engaged with the movable guide rails 12 through a fixed plate. A guide rod is also provided between the fixed plate and the moving plate. The upper end of the guide rod is fixed to the lower end face of the fixed plate, and the lower end of the guide rod passes through the moving plate. Multiple support rods 10 are installed in the support rod mounting holes on the moving plate. The support rod mounting holes are oblong holes, and the length of the oblong holes is greater than the sum of the outer diameters of the multiple support rods 10 (see...). Figure 2The sum of the widths of the three support rods 10 is less than the length of the oblong hole, allowing the three support rods 10 to be adjusted left and right within the oblong hole to accommodate corrugated plates with different wave pitches. The pressure roller 9 is rotatably connected to the lower end of the support rod 10 via a rotating shaft, and the installation positions of the pressure roller 9 include the middle of the lower end of the support rod 10, the left side of the lower end of the support rod 10, and the right side of the lower end of the support rod 10 (e.g.,...). Figure 2 (The pressure rollers 9 at the lower ends of the three support rods 10 from left to right are located on the right, middle and left sides respectively.) This design can avoid interference between different pressure rollers 9 caused by different corrugated plate pitches.

[0021] As one solution, the variable diameter expansion tooling 8 contains four expansion blocks with a radial expansion range of 0 to 25 mm. The radial movement of the expansion blocks is adjustable with a precision of 0.1 mm, and the tensioning pressure and tensioning dimension are digitally adjustable. The variable diameter expansion tooling 8 can rotate around its central axis, which makes it convenient for the laser quenching head 4 to remain stationary during the welding process, while the annular heat sink 7 rotates to complete the welding of one circle of the corrugated plate.

[0022] As one solution, such as Figure 3 The laser welding apparatus also includes a protective cover for introducing argon gas during welding. The protective cover is positioned between the laser quenching head 4 and the annular heat sink 7 and behind the pressure roller mechanism 5. (In this embodiment, the corrugated shell 14 is installed below the moving plate of the pressure roller seat 11. The laser beam through-hole at the upper end of the corrugated shell 14 is aligned with the laser welding through-hole on the moving plate and the fixed plate. During welding, the corrugated plate is first pressed by the pressure roller mechanism 5, and then the welding is completed by the laser beam 16 in the protective cover.) The protective cover includes the corrugated shell 14, which is a hollow shell. The lower end of the corrugated shell 14 is a corrugated groove, the shape and size of which match the crests and troughs of the corrugated plate. Figure 3 The corrugated slot matches two peaks and one trough on the corrugated plate. The upper end of the corrugated profile housing 14 has a laser beam through hole for the laser beam 16 emitted by the laser sedation head 4 to pass through. A ring of anti-flow edge 17 is provided around the laser beam through hole. The anti-flow edge 17 is cylindrical and perpendicular to the upper end of the corrugated profile housing 14. An argon gas inlet 15 is provided on each of the two opposite sides of the corrugated profile housing 14.

[0023] The laser welding method for titanium alloy annular heat sinks using the above-mentioned laser welding apparatus includes the following steps: Step 1: Reduce the outer diameter of the reducing expansion tool 8 to 885mm and align it with the reference ( Figure 1 The leftmost end of the variable diameter expansion tooling 8 is placed into the titanium alloy annular radiator 7, and 8 corrugated plates are attached to the inner cylinder surface of the annular radiator 7. Step 2: Adjust the outer diameter of the variable diameter expansion tool 8 to 903mm, and then manually increase the size of the variable diameter expansion tool 8 so that the inner surface of the inner cylinder of the annular radiator 7 is in close contact with the outer surface of the variable diameter expansion tool 8. Step 3: Locate the weld position of the corrugated plate using the laser vision tracker 6 and feed the position information back to the robot 3. The robot 3 then drives the robotic arm to move the laser calming head 4 above the weld position. Step 4: Based on the weld position information fed back by the laser vision tracker 6, move the pressure roller mechanism 5 above the weld position. The pressure roller mechanism 5 provides a downward pressure of 500KN through the cylinder 2 to push the moving plate down. The moving plate then drives the support rod 10 and the pressure roller 9 to press the corrugated plate tightly, ensuring that the inner cylinder of the annular radiator 7 is in close contact with the corrugated plate. Figure 2 The image shows three pressure rollers 9 pressing against three adjacent troughs of the corrugated plate, with the middle trough serving as the weld location. The left pressure roller 9 is installed on the right side of the lower end of the support rod 10, the middle pressure roller 9 is installed in the middle position of the lower end of the support rod 10, and the right pressure roller 9 is installed on the left side of the lower end of the support rod 10, thus ensuring the symmetry of the clamping force. Step 5: Pour argon gas into the back, inner cavity, and front of the annular radiator 7 for protection. Specifically, argon gas is used for the front of the annular radiator 7. Figure 3 The protective cover shown is filled with argon gas. The corrugated shell 14 adopts a contour design (conforming to the corrugated plate). The distance between the corrugated shell 14 and the corrugated plate is controlled between 2 and 3 mm. The upper end of the corrugated shell 14 is reserved with a laser beam 16 through hole with a diameter of 8 mm. An anti-flow edge 17 is set along the circumference of the through hole with a height of 5 mm. After adjusting the welding parameters, laser welding is started. The joint of the weld is the lap weld of the corrugated plate and the inner cylinder. Step 6: After completing each weld, repeat steps 3 and 4 before welding the next weld. After all welds are completed, reduce the outer diameter of the variable diameter expansion tool 8 and remove the annular radiator 7.

[0024] The laser welding method described above solves the problems of low efficiency and large spatter in the internal cavity when welding titanium alloy ring heat sinks using traditional resistance welding processes.

[0025] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A laser welding device for a titanium alloy annular heat sink, characterized in that, include: Support beam (1), wherein the support beam (1) is a rigid frame; A variable diameter expansion tool (8) is installed inside the support beam (1) to expand and clamp the annular radiator (7) from the inside out. The outer surface of the variable diameter expansion tool (8) is a cylindrical surface with a variable diameter. Robot (3), which is a welding robot and is located outside the support beam (1), the robot (3) includes a mechanical arm for welding, and a laser galvanometer (4) is installed on the mechanical arm. The pressure roller mechanism (5) is slidably connected to the support beam (1) and located above the variable diameter expansion tooling (8). The sliding direction of the pressure roller mechanism (5) is parallel to the axial direction of the variable diameter expansion tooling (8). The pressure roller mechanism (5) mainly consists of a cylinder (2), a pressure roller seat (11), a pressure roller (9), a support rod (10), and a spring (13), wherein: The pressure roller seat (11) includes a fixed plate and a movable plate arranged in parallel in the upper and lower directions and capable of moving relative to each other. The fixed plate is slidably fitted with the support beam (1). The movable plate has a support rod mounting hole. The fixed plate and the movable plate have laser welding through holes in the same position. The cylinder (2) is mounted on the fixed plate, and the piston rod of the cylinder (2) passes through the fixed plate and is connected to the moving plate; The surface of the support rod (10) has external threads and annular protrusions. After the support rod (10) passes through the support rod mounting hole of the moving plate, its upper end is assembled with a nut through external threads, and its lower end is rotatably connected to the pressure roller (9). The spring (13) is sleeved on the support rod (10) and the upper end of the spring (13) is close to the lower end face of the moving plate, and the lower end of the spring (13) is close to the annular protrusion end face of the support rod (10). A laser vision tracker (6) is installed on the pressure roller seat (11) to transmit the weld position information to the robot (3) in real time, thereby controlling the position of the laser oscillator (4). Two movable guide rails (12) are installed in parallel on the support beam (1). The extension direction of the movable guide rails (12) is parallel to the axial direction of the variable diameter expansion tool (8). The pressure roller seat (11) slides with the movable guide rails (12) through the fixed plate. A guide rod is also provided between the fixed plate and the moving plate. The upper end of the guide rod is fixed to the lower end face of the fixed plate, and the lower end of the guide rod passes through the moving plate. It also includes a protective cover for introducing welding shielding gas. The protective cover is set between the laser diaphragm head (4) and the annular heat sink (7). The protective cover includes a wave-shaped profiled shell (14). The lower end of the wave-shaped profiled shell (14) is a wave-shaped groove. The shape and size of the wave-shaped groove match the crests and troughs of the corrugated plate. The upper end of the wave-shaped profiled shell (14) has a laser beam through hole. A ring of anti-flow edge (17) is provided along the circumference of the laser beam through hole. The side of the wave-shaped profiled shell (14) is provided with a shielding gas inlet.

2. The laser welding apparatus for a titanium alloy annular heat sink according to claim 1, characterized in that: Multiple support rods (10) are installed in the support rod mounting holes on the moving plate, and the length of the support rod mounting holes is greater than the sum of the outer diameters of the multiple support rods (10).

3. The laser welding apparatus for a titanium alloy annular heat sink according to claim 1, characterized in that: The pressure roller (9) is rotatably connected to the lower end of the support rod (10) via a rotating shaft, and the installation positions of the pressure roller (9) include the middle of the lower end of the support rod (10), the left side of the lower end of the support rod (10), and the right side of the lower end of the support rod (10).

4. The laser welding apparatus for a titanium alloy annular heat sink according to claim 1, characterized in that: The variable diameter expansion tool (8) contains four expansion blocks, with a radial expansion range of 0 to 25 mm. The radial movement of the expansion blocks is adjustable with a precision of 0.1 mm. The variable diameter expansion tool (8) can rotate around its own axis.

5. A laser welding method for a titanium alloy annular heat sink, characterized in that, The laser welding apparatus of claim 1 is used, and the process includes the following steps: Step 1: Reduce the outer diameter of the variable diameter expansion tool (8) and install the annular heat sink (7) with corrugated plate. Step 2: Adjust the outer diameter of the variable diameter expansion tool (8) so that the inner surface of the annular radiator (7) is in close contact with the outer surface of the variable diameter expansion tool (8); Step 3: Locate the weld position of the corrugated plate using the laser vision tracker (6) and feed the position information back to the robot (3); Step 4: Adjust the position of the pressure roller mechanism (5) according to the weld position information fed back by the laser vision tracker (6), start the cylinder (2) to press down at the set pressure until the pressure roller (9) presses the corrugated plate. The pressing position of the pressure roller (9) is the trough of the corrugated plate, ensuring that the inner cylinder of the annular radiator (7) is in close contact with the corrugated plate. Step 5: Fill the back, inner cavity and front of the annular radiator (7) with argon gas for protection, and start laser welding; Step 6: After all welds are completed, reduce the outer diameter of the variable diameter expansion tool (8) and remove the annular radiator (7).

6. The laser welding method for a titanium alloy annular heat sink according to claim 5, characterized in that: In step 1, the corrugated plate overlaps the inner cylinder surface of the annular radiator (7).

7. The laser welding method for a titanium alloy annular heat sink according to claim 5, characterized in that: In step 3, the weld position that the laser vision tracker (6) locates is the middle of the trough of the corrugated plate.

8. The laser welding method for a titanium alloy annular heat sink according to claim 5, characterized in that: In step 4, adjusting the position of the pressure roller mechanism (5) includes: Slide the pressure roller seat (11) on the support beam (1); Adjust the position of the support rod (10) inside the support rod mounting hole; A pressure roller (9) is set at the trough of the corrugated plate corresponding to the weld position. A pressure roller (9) is symmetrically set on the left and right sides of the aforementioned pressure roller (9), and the two pressure rollers (9) are pressed into the trough of the corrugated plate on the left and right sides of the aforementioned trough.

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