CN111085780A - Laser welding method for metal container - Google Patents

Abstract

The invention discloses a laser welding method for metal containers, comprising the following steps: step 1, providing a first base material and a second base material; step 2, using a special fixture to accurately butt the first base material and the second base material; Step 3, provide a laser deep penetration welding system; Step 4, provide a remote laser heat conduction welding system; Step 5, turn on the laser generator, control one-to-two shutters, and output the first laser beam through the first laser welding head; Step 6: Turn on the protective gas blowing device; Step 7, control one-to-two shutters, and output the second laser beam through the second laser welding head; Step 8, the second welding manipulator clamps the second laser welding head and moves along the welding track; Step 9 , When the first laser beam moves to the welding end point, the laser deep penetration welding is completed; Step 10, when the second laser beam moves to the welding end point, the laser heat conduction welding is completed; Step 11, Turn off the laser generator to complete the welding process .

Description

A laser welding method for metal containers

technical field

The invention relates to the field of welding, in particular to a laser welding method and system for metal containers.

Background technique

Laser welding is one of the most widely used advanced processes in laser processing technology. It has the advantages of easy manipulation of welding heat source, simple control, small deformation of weldment, narrow heat-affected zone, low residual stress, high precision and high degree of automation. It has been applied in important industries of the national economy such as automobiles, shipbuilding, nuclear power, and pipelines.

Usually, according to the different heat conduction mechanisms, laser welding is divided into two modes: laser heat conduction welding and laser deep penetration welding or laser pinhole welding. The laser energy coupling absorption mechanism, weld formation and final welding effect of these two welding modes are completely different. . The laser heat conduction welding process is similar to the heat conduction mode of tungsten gas tungsten arc welding (TIG). Laser deep penetration welding mode is a common application mode of laser welding, which has the outstanding advantages of large welding seam aspect ratio, high welding precision and high welding efficiency. Laser deep penetration welding is similar to electron beam welding. The high energy density laser causes local evaporation of the material. Under the action of evaporation pressure, the surface of the molten pool sags to form small holes. The laser beam penetrates into the molten pool through the "small holes". The evaporated metal vapor continues to be ionized under the action of a high-energy-density laser, and a photoplasma is formed inside and above the small hole. Comparing the two welding modes of heat conduction welding and deep penetration welding, it can be found that the essential difference between the two is whether the formation of small holes and plasma. It can be said that the pinhole effect is the essential feature of laser deep penetration welding. Due to the dynamic oscillation of small holes in laser deep penetration welding, the collapse of small holes will directly lead to porosity, so the weld formed by the solidification of the molten pool of laser deep penetration welding often has porosity defects. However, there are no small holes in the laser heat conduction welding process, the flow of the molten pool is stable, and there is generally no porosity defect.

The metal containers in the pharmaceutical industry have extremely strict requirements on the pores of the welding seam due to the stored raw materials, and it is basically impossible to allow defects such as pores on the surface of the welding seam on the inner wall of the metal container. The existing welding process is manual TIG, which needs to be polished after welding, and the processing efficiency is low. . Using the laser welding process, the porosity defect is difficult to control and cannot meet the requirements.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a laser welding method and system for metal containers, aiming at defects such as pores easily formed during the laser welding of metal containers.

The invention provides a laser welding method for metal containers, the specific steps of which are as follows:

Step 1: Provide the first base material and the second base material.

Step 2: Use a special fixture to accurately butt the first base metal and the second base metal.

Step 3: Provide a laser deep penetration welding system. The laser deep penetration welding system includes a laser generator, a first transmission optical fiber, one drag and two gates, a second transmission optical fiber, a first welding manipulator, a first laser welding head, and protective gas blowing The device, the laser generator is connected with the one-to-two switch via the first transmission optical fiber, and then the one-to-two switch is connected to the first laser welding head via the second transmission optical fiber.

Step 4: Provide a remote laser heat conduction welding system. The remote laser heat conduction welding system includes a laser generator, a first transmission optical fiber, one drag and two gates, a third transmission optical fiber, a second welding manipulator, a second laser welding head, and a laser generator The first transmission optical fiber is connected to the one-to-two gate, and then the one-to-two gate is connected to the second laser welding head via the third transmission optical fiber.

Step 5: Turn on the laser generator, control the one-to-two shutter, and output the first laser beam through the first transmission fiber, the second transmission fiber and the first laser welding head, and the first laser beam vertically irradiates the outer surface of the butt joint.

Step 6: The protective gas blowing device is turned on, the protective gas is blown to the welding area, and the first welding manipulator clamps the first laser welding head and moves along the welding track to implement laser deep penetration welding.

Step 7: Control the one-to-two optical gate, connect the first transmission fiber, the third transmission fiber and the second laser welding head to output the second laser beam, and the second laser beam is irradiated by the long-distance laser deep penetration welding to solidify the full penetration Bottom of weld.

Step 8: The second welding manipulator clamps the second laser welding head to move along the welding track, performs remote laser heat conduction welding, and obtains a laser heat conduction weld. After the welding pool is cooled, a joint is formed together.

Step 9: When the first laser beam moves to the welding end point, control one and two shutters, turn off the first laser beam, turn off the gas protection device, and complete the laser deep penetration welding.

Step 10: When the second laser beam moves to the welding end point, control one and two shutters to turn off the second laser beam to complete the laser heat conduction welding.

Step 11: Turn off the laser generator, and the first welding manipulator and the second welding manipulator return to their original positions to complete the welding process.

Further, in step 1, the thickness of the first base material and the second base material is 3-6 mm.

Further, in step 3, the power of the laser generator is 6-10 kW.

Further, in step 3, the first laser welding head is a fixed mirror group welding head.

Further, the focusing focal length of the first laser welding head is 150-300 mm.

Further, the size of the focusing focal spot of the first laser welding head is Φ 0.2~Φ 0.6 mm.

Further, in step 4, the second laser welding head is a galvanometer type welding head.

Further, the focusing focal length of the second laser welding head is 500-1000 mm.

Further, the size of the focusing focal spot of the second laser welding head is Φ 0.8~Φ1.5 mm.

Further, in step 6, the laser deep penetration welding form is full penetration welding to obtain a full penetration weld.

Further, in step 7, the included angle θ between the second laser beam and the first base material and the lower surface of the second base material is 60°˜90°.

Further, in step 7, the distance d between the center of the second laser beam welding area and the center of the first laser beam welding area is 2-5 mm.

Further, in step 8, the penetration depth δ of the laser heat conduction welding is 1 to 2.5 mm.

The invention also provides a laser welding system for metal containers, including two subsystems, a laser deep penetration welding system and a remote laser heat conduction welding system. Irradiate the outer surface of the butt joint to realize laser deep penetration welding and obtain a full penetration weld. Laser heat conduction welding, after the welding pool is cooled, the joints are formed together, and the welding process is completed. Two laser welding heads are fixedly connected to the second connecting flange at the end of the second manipulator.

Further, the laser deep penetration welding system further includes a protective gas blowing device corresponding to the first laser welding head.

Further, the first laser welding head is a fixed mirror group welding head.

Further, the second laser welding head is a galvanometer type welding head.

Further, the form of laser deep penetration welding is full penetration welding to obtain a full penetration weld.

Further, the included angle θ between the second laser beam and the first base material and the lower surface of the second base material is 60°˜90°.

Beneficial effects of the present invention:

1) In the present invention, the first laser beam is used to carry out laser deep penetration welding on the outer surface of the butt joint to obtain a full penetration weld, which realizes the high-efficiency and high-precision welding connection of the butt joint, and then the second laser beam is used. Perform remote laser heat conduction welding on the bottom of the full penetration weld to obtain a laser heat conduction weld. Laser heat conduction welding remelts the bottom of the full penetration weld formed by laser deep penetration welding, so that the pores at the bottom of the full penetration weld overflow. The laser heat conducts the welding molten pool, therefore, after the welding molten pool is cooled, there is no porosity defect at the bottom of the joint joint formed together, and the surface of the welding seam on the inner wall of the metal container has no porosity defect.

2) The laser welding method and system for metal containers provided by the present invention avoids the problems of large deformation and low efficiency of traditional manual arc welding parts, and has the outstanding characteristics of small deformation and high efficiency.

Description of drawings:

FIG. 1 is a schematic diagram of a laser welding method for a metal container according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a longitudinal section of the laser welding area in the method shown in FIG. 1 .

Figure 3 is a schematic diagram of a butt joint.

Among them: 1-first base material, 2-second base material, 3-laser transmitter, 4-first transmission fiber, 5-one-to-two shutters, 6-second transmission fiber, 7-first welding manipulator , 8- the first connecting flange, 9- the first laser welding head, 10- the first laser beam, 11- fixing bracket, 12- protective gas device, 13- metal container, 14- the third transmission fiber, 15- the first Two laser welding heads, 16-second connecting flange, 17-second laser beam, 18-second welding manipulator, 19-small hole, 20-deep penetration welding pool, 21-full penetration weld, 22-full Bottom of penetration weld, 23-laser heat conduction weld, 24-laser heat conduction weld bottom, 25-laser heat conduction weld pool.

Detailed ways:

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings 1-3 and specific embodiments.

As shown in Figures 1-3, in an example of the present invention, a laser welding method for a metal container includes the following steps:

In step 1, a first base material 1 and a second base material 2 are provided.

Optionally, the thickness of the first base material 1 and the second base material 2 is 3-6 mm.

Step 2, using a special fixture to accurately butt the first base metal 1 and the second base metal 2.

In step 3, a laser deep penetration welding system is provided. The laser deep penetration welding system includes a laser generator 3, a first transmission optical fiber 4, one drag and two gates 5, a second transmission optical fiber 6, a first welding manipulator 7, and a first laser welding The head 9, the protective gas blowing device 12, the laser generator 3 is connected to the one-to-two gate 5 via the first transmission optical fiber 4, and then the one-to-two gate 5 is connected to the first laser welding head 9 via the second transmission optical fiber 6.

Optionally, the power of the laser generator 3 is 6-10 kW.

Optionally, the first laser welding head 9 is a fixed lens group welding head, the focusing focal length of the first laser welding head 9 is 150-300 mm, and the focusing focal spot size of the first laser welding head 9 is Φ 0.2-Φ 0.6 mm.

Step 4, provide a remote laser heat conduction welding system, the remote laser heat conduction welding system includes a laser generator 3, a first transmission optical fiber 4, a one-to-two switch 5, a third transmission optical fiber 14, a second welding manipulator 18, and a second laser welding Head 15 , the laser generator 3 is connected to the one-to-two switch 5 via the first transmission optical fiber 4 , and then the one-to-two switch 5 is connected to the second laser welding head 15 via the third transmission optical fiber 14 .

Optionally, the second laser welding head 15 is a galvanometer type welding head, the focusing focal length of the second laser welding head 15 is 500-1000 mm, and the focusing focal spot size of the second laser welding head 15 is Φ 0.8-Φ1.5 mm.

Step 5, turn on the laser generator 3, control the one-to-two optical gate 5, and output the first laser beam 10 through the first transmission optical fiber 4, the second transmission optical fiber 6 and the first laser welding head 9, and the first laser beam 10 radiates vertically. according to the outer surface of the butt joint.

In step 6, the shielding gas blowing device 12 is turned on, the shielding gas is blown toward the welding area, and the first welding manipulator 7 clamps the first laser welding head 9 and moves along the welding track to implement laser deep penetration welding.

Optionally, the form of laser deep penetration welding is full penetration welding to obtain a full penetration weld 21 .

Step 7, control one-to-two optical gates 5, and output the second laser beam 17 through the connection of the first transmission optical fiber 4, the third transmission optical fiber 14 and the second laser welding head 15, and the second laser beam 17 irradiates the laser deep melting at a long distance. Weld the solidified full penetration weld bottom 22 .

Optionally, the included angle θ between the second laser beam 17 and the lower surfaces of the first base material 1 and the second base material 2 is 60°˜90°.

Optionally, the distance d between the center of the welding area of the second laser beam 17 and the center of the welding area of the first laser beam 10 is 2˜5 mm.

Step 8, the second welding manipulator 18 clamps the second laser welding head 15 and moves along the welding track to perform remote laser heat conduction welding to obtain the laser heat conduction weld 23. After the deep penetration welding molten pool 20 and the laser heat conduction welding molten pool 25 are cooled together to form a joint.

Optionally, the laser heat conduction welding penetration δ is 1 to 2.5 mm.

Step 9, when the first laser beam 10 moves to the welding end point, control the one-to-two shutter 5, turn off the first laser beam 10, turn off the gas protection device 12, and complete the laser deep penetration welding.

In step 10, when the second laser beam 17 moves to the welding end point, the one-to-two shutter 5 is controlled to turn off the second laser beam 17 to complete the laser heat conduction welding.

Step 11, the laser generator 5 is turned off, the first welding robot 7 and the second welding robot 18 are returned to their original positions, and the welding process is completed.

Claims (7)

1. a laser welding method facing metal container, is characterized in that comprising the steps: Step 1. Provide the first base metal (1) and the second base metal (2); Step 2. Use a special fixture to accurately connect the first base metal (1) and the second base metal (2); Step 3. Provide a laser deep penetration welding system. The laser deep penetration welding system includes a laser generator (3), a first transmission optical fiber (4), one for two gates (5), a second transmission optical fiber (6), a first transmission optical fiber (6), and a first transmission optical fiber (4). The welding manipulator (7), the first laser welding head (9), the protective gas blowing device (12), and the laser generator (3) are connected to the one-to-two gate (5) through the first transmission optical fiber (4), and then a The drag two gate (5) is connected with the first laser welding head (9) through the second transmission optical fiber (6); Step 4. Provide a remote laser heat conduction welding system. The remote laser heat conduction welding system includes a laser generator (3), a first transmission optical fiber (4), one for two gates (5), a third transmission optical fiber (14), and a second transmission optical fiber (14). The welding manipulator (18), the second laser welding head (15), and the laser generator (3) are connected to the one-to-two gate (5) via the first transmission optical fiber (4), and then the one-to-two gate (5) passes through the The third transmission optical fiber (14) is connected to the second laser welding head (15); Step 5. Turn on the laser generator (3), control the one-to-two shutter (5), and output the first laser through the first transmission fiber (4), the second transmission fiber (6) and the first laser welding head (9). a beam (10), the first laser beam (10) vertically irradiates the outer surface of the butt joint; Step 6. Turn on the protective gas blowing device (12), the protective gas is blown to the welding area, the first welding manipulator (7) clamps the first laser welding head (9) and moves along the welding track to implement laser deep penetration welding; Step 7. Control the one-to-two optical gate (5), and output the second laser beam (17) through the first transmission fiber (4), the third transmission fiber (14) and the second laser welding head (15), and the second laser beam (17) is connected. The laser beam (17) irradiates the bottom (22) of the full penetration weld solidified by laser deep penetration welding at a long distance; Step 8. The second welding manipulator (18) clamps the second laser welding head (15) to move along the welding track, and performs remote laser heat conduction welding to obtain the laser heat conduction weld (23), the deep penetration welding molten pool (20) and The laser heat conduction welding molten pool (25) forms joints together after cooling; Step 9. When the first laser beam (10) moves to the welding end point, control the one-to-two shutter (5), turn off the first laser beam (10), turn off the gas protection device (12), and complete the laser deep penetration welding ; Step 10. When the second laser beam (17) moves to the welding end point, control the one-to-two shutter (5), turn off the second laser beam (17), and complete the laser heat conduction welding; Step 11. Turn off the laser generator (3), and the first welding manipulator (7) and the second welding manipulator (18) return to their original positions to complete the welding process. 2 . The laser welding method for metal containers according to claim 1 , wherein in step 6 , the laser deep penetration welding is in the form of full penetration welding to obtain a full penetration weld ( 21 ). 3 . 3 . The laser welding method for metal containers according to claim 1 , wherein in step 7 , the second laser beam ( 17 ) is connected to the first base metal ( 1 ) and the second base metal ( 2 ). 4 . The surface angle θ is 60°~90°. 4. The laser welding method for metal containers according to claim 1, characterized in that: in step 7, the distance between the center of the welding area of the second laser beam (17) and the center of the welding area of the first laser beam (10) d is 2 to 5 mm. 5. The laser welding method for metal containers according to claim 1, wherein in step 8, the laser heat conduction welding penetration δ is 1 to 2.5 mm, and the laser welding method for metal containers is characterized in that: The laser welding system includes two subsystems, a laser deep penetration welding system and a remote laser heat conduction welding system. In the laser deep penetration welding system, a first laser beam (10) formed by focusing a first laser welding head (9) vertically irradiates the outer surface of the butt joint , realize laser deep penetration welding, and obtain a full penetration weld (21), and the second laser beam formed by the focusing of the second laser welding head irradiates the bottom of the full penetration weld solidified by laser deep penetration welding (22) at a long distance, so as to realize In the remote laser heat conduction welding, the deep penetration welding molten pool (20) and the laser heat conduction welding molten pool (25) are cooled together to form a connecting joint, and the welding process is completed. The first laser welding head in the laser deep penetration welding system and the remote laser heat conduction welding system (9) The first connecting flange (8) fixedly connected to the end of the first welding manipulator (7) and the second connecting flange (8) of the second laser welding head (15) fixedly connected to the end of the second welding manipulator (18). 16) on. 6 . The laser welding method for metal containers according to claim 6 , wherein the first laser welding head ( 9 ) is a fixed mirror group welding head. 7 . 7 . The laser welding method for metal containers according to claim 6 , wherein the second laser welding head ( 15 ) is a galvanometer type welding head. 8 .

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