CN112719582A - Laser welding device with preheating function and preheating welding method - Google Patents

Abstract

The invention provides a laser welding device with a preheating function and a preheating welding method, wherein the preheating welding device comprises: laser preheating system and laser welding platform. The laser preheating welding system comprises a semiconductor laser and a fiber laser, wherein the semiconductor laser is used for outputting laser with the wavelength of 800nm and laser with the wavelength of 1060nm, the fiber laser is arranged outside the laser, and a laser preheating head and a laser welding head are arranged outside the laser, and the laser preheating head and the laser welding head are used for adjusting the focal length and the working distance to obtain light spots with proper sizes; the welding platform is provided with a tool clamp for clamping a weldment and a working platform for supporting the tool clamp, wherein the tool clamp can move relative to the working platform. According to the invention, the welding seam of the welding piece is preheated by adopting the large-size diameter laser beam of the semiconductor laser, the welding pieces with different structures and sizes can be heated, the applicability is strong, the heating efficiency is high, the preheating region is accurate, and the problems of preheating of redundant parts outside the welding seam and internal and external temperature difference of the welding piece do not exist.

Description

Laser welding device with preheating function and preheating welding method

Technical Field

The invention relates to the technical field of laser welding, in particular to a laser welding device with a preheating function and a preheating welding method, and particularly relates to a laser preheating welding device for 2219 aluminum alloy of a rocket fuel storage tank.

Background

The 2219 aluminum alloy has the characteristics of high specific strength, good low-temperature and high-temperature mechanical properties, high fracture toughness and good stress corrosion resistance, is suitable for a fuel tank and an oxidant tank for aerospace rocket welding, skin and structural parts of supersonic aircraft and a new generation rocket storage tank in China with the working temperature of-270 ℃ to-300 ℃, and is widely applied to the aerospace and aviation fields; at present, the connection process of the rocket fuel storage tank is continuously updated, and because the production of the rocket fuel storage tank must ensure high quality and high efficiency, laser welding is gradually applied to the welding connection with the structure of the rocket fuel storage tank, but the defect of laser welding aluminum alloy is difficult to overcome, so the actual application of the rocket fuel storage tank is hindered.

Along with the rapid development of science and technology, particularly the vigorous development of aerospace industry, the demand of high-quality aluminum alloy laser welding components is increasing day by day in recent years; three main problems exist in laser welding of aluminum alloys: firstly, the defects of pores and the like are easily formed in the welding seam, secondly, the welding joint is not completely melted, and thirdly, the welding seam molten pool is seriously splashed; therefore, the problem of aluminum alloy laser welding is becoming a key issue in the research of laser welding technology today.

When the 2219 aluminum alloy is changed from liquid state to solid state in the laser welding process, the hydrogen content in the high-temperature liquid molten pool is about 20 times of the hydrogen content in the low-temperature solidification welding line, and redundant hydrogen must be separated out in the solidification process of the welding molten pool, so that welding air holes are easily formed; because the liquid metal below the laser keyhole of the aluminum alloy in the high-temperature environment permeates the back of the weldment, the fusion width of the back after welding is narrow, and the phenomenon of incomplete fusion is easy to generate; in the laser welding process, the laser power density is too high, so that a workpiece absorbs more laser energy in a short time, the material is seriously vaporized, the local temperature is too high, and the weld pool reacts violently and easily forms welding spatter; preheating has the effect of reducing the regional difference in temperature of welded joint, the produced internal stress of reduction welding process, and the method of preheating aluminum alloy weldment at present is electric arc preheating mostly, and electric arc preheating is for jumbo size weldment, and the heating region is big, and is difficult to control, nevertheless will not reach accurate purpose of preheating to the jumbo size weldment, and the heating region will influence the material characteristic around the welding seam greatly simultaneously, reduces the welded joint quality.

Therefore, how to provide a laser preheating welding device that laser welding aluminum alloy preweld that suitability is strong and can improve weldment accuracy and preheat effect and welding efficiency is the technical problem that technical staff in the field need solve at present.

Patent document CN 106514075B discloses application of welding preheating device, which belongs to the technical field of welding preheating, and the application of welding preheating device, and the welding preheating device includes a body, and the body includes positioning mechanism and preheating mechanism, and still includes adjustment mechanism, and positioning mechanism sets up in welding seam side below, and preheating mechanism sets up at the bottom end face that is close to the welding seam, and adjustment mechanism connects between positioning mechanism and preheating mechanism, adjusts the degree of compressing tightly of preheating mechanism and welding seam bottom end face, through the step of equipment → installation and regulation → dismantlement. According to the invention, the preheating mechanism is positioned close to the preheating object through the positioning mechanism, and the adjusting mechanism adjusts the preheating mechanism to adjust the compaction degree between the preheating object and the preheating mechanism, so that the technical problem of poor control of preheating time or temperature is effectively solved. The structure and performance of the patent still leaves room for improvement.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a laser welding device with a preheating function and a preheating welding method.

According to the present invention, there is provided a laser welding apparatus having a preheating function, comprising: preheating the welding system, thewelding platform 10; the preheat welding system includes: welding afiber laser 1, asemiconductor laser 2, alaser preheating head 5 and alaser welding head 6; thewelding fiber laser 1 includes: atemperature controller 3; thetemperature controller 3 can detect the temperature of the preheatingsemiconductor laser 2 and the weldingoptical fiber laser 1; thetemperature controller 3 can control the temperature of thewelding fiber laser 1; thesemiconductor laser 2 and theoptical fiber laser 1 are externally provided with alaser preheating head 5 and alaser welding head 6 which are used for adjusting focal length and working distance to obtain light spots with proper sizes; thewelding stage 10 is disposed at a lower portion of the preheating welding system.

Preferably, the preheat welding system further comprises: adrive power supply 4; thetemperature controller 3 can utilize cooling water to cool the laser, and is externally provided with adriving power supply 4 for controlling the laser to start.

Preferably, the method further comprises the following steps: aweldment 9;

the preheat welding system further includes: an infraredtemperature measurement sensor 7;

the infraredtemperature measurement sensor 7 can be used for detecting the preheating temperature and the welding temperature of theweldment 9.

Preferably, the preheat welding system further comprises: a precise tracking andpositioning sensor 8;

the accurate tracking andpositioning sensor 8 can be used for visually recognizing the welding seam.

Preferably, the method further comprises the following steps: a control system;

and thetemperature controller 3, thedriving power supply 4, the infraredtemperature measuring sensor 7, thesemiconductor laser 2, thewelding fiber laser 1, thelaser preheating head 5 and thelaser welding head 6 are all connected to a control system.

Preferably, the method further comprises the following steps: the device comprises aheight adjuster 11, apositioning piece 12, apressing rod 13 and alocking pin 14; thepositioning piece 12 can fix the position of theweldment 9; theheight adjuster 11 is nested in thepositioning piece 12; thepressing rod 13 can press theweldment 9; the height adjuster 11 longitudinally fixes thepressing rod 13;

thelocking pin 14 can be screwed to theclamping lever 13.

The invention aims to provide a laser preheating welding device which can further improve the welding quality and the production efficiency, can further improve the accurate preheating effect, the welding efficiency and the welding quality of a weldment and is suitable for welding a rocket fuel storage tank body structure.

The purpose of the invention is realized by the following technical scheme: the utility model provides a laser preheating welding device that laser welding aluminum alloy preheats before welding, laser preheating welding device is including preheating welding system and welded platform, preheats semiconductor laser and welds the fiber laser and connect laser preheating head and laser welder head respectively, installs infrared temperature sensor and accurate tracking position sensor on every laser head.

The invention provides a preheating welding method, which adopts a laser welding device with a preheating function, and comprises the following steps:

step S1: setting a temperature controller for detecting the preheating semiconductor laser and the welding fiber laser;

step S2: arranging a laser preheating head and a laser welding head outside the semiconductor laser and the optical fiber laser for adjusting the focal length and the working distance to obtain light spots with proper sizes;

step S3: the temperature controller is adopted to cool the laser by using cooling water, and a driving power supply for controlling the laser to start is arranged outside the laser.

Step S4: the welding fixture comprises a welding platform, wherein a tooling fixture for clamping the weldment and a base platform for supporting the tooling fixture are arranged on the welding platform, and the tooling fixture can move relative to the base platform.

Preferably, the method further comprises the following steps:

step S5: an infrared temperature measuring sensor for detecting the preheating temperature and the welding temperature of the weldment and an accurate tracking and positioning sensor for visually identifying the welding line are arranged in the preheating welding system.

Preferably, the method further comprises the following steps:

step S6: firstly, heating the welding seam of a weldment by a laser preheating head according to a route positioned by a precise tracking and positioning sensor, and monitoring the temperature of the welding seam of the weldment by using an infrared temperature measuring sensor;

step S7: when the temperature of the welding seam reaches the welding requirement, welding the welding seam by using the laser welding head, monitoring the temperature of the welding seam by using the infrared temperature measuring sensor, and scanning all the welding seams by using the accurate tracking and positioning sensor;

step S8: and a laser welding head is utilized to weld according to the route positioned by the accurate tracking positioning sensor, and then one welding operation is completed, namely one welding operation is completed, and at the moment, the welding of the optical fiber laser and the control system is stopped. And moving the accurate tracking and positioning sensor, the laser preheating head and the laser welding head to the next welding line, and starting to perform the next preheating welding operation.

The invention provides a laser preheating welding device for laser welding aluminum alloy pre-welding, which comprises a preheating welding system and a welding platform, wherein the preheating welding system comprises a temperature controller for detecting a preheating semiconductor laser and a welding fiber laser, the outer parts of the semiconductor laser and the fiber laser are respectively provided with a laser preheating head and a laser welding head for adjusting focal length and working distance to obtain light spots with proper sizes, the temperature controller utilizes cooling water to cool the laser, and the outer part of the temperature controller is provided with a driving power supply for controlling the laser to start; the welding platform is provided with a tool clamp for clamping a weldment and a base platform for supporting the tool clamp, and the tool clamp can move relative to the base platform.

The invention provides a laser welding device for preheating before welding, which comprises: laser preheating system and laser welding platform. The laser preheating welding system comprises a semiconductor laser and a fiber laser, wherein the semiconductor laser is used for outputting laser with the wavelength of 800nm and laser with the wavelength of 1060nm, the fiber laser is arranged outside the laser, and a laser preheating head and a laser welding head are arranged outside the laser, and the laser preheating head and the laser welding head are used for adjusting the focal length and the working distance to obtain light spots with proper sizes; the welding platform is provided with a tool clamp for clamping a weldment and a working platform for supporting the tool clamp, wherein the tool clamp can move relative to the working platform. According to the invention, the welding seam of the welding piece is preheated by adopting the large-size diameter laser beam of the semiconductor laser, the welding pieces with different structures and sizes can be heated, the applicability is strong, the heating efficiency is high, the preheating region is accurate, and the problems of preheating of redundant parts outside the welding seam and internal and external temperature difference of the welding piece do not exist.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention adopts a heating mode of laser induced current heating instead of surface heat conduction, so that weldments with different structures can be preheated and welded, and the applicability is stronger;

2. the invention adopts a laser heating mode, has more accurate preheating range than an electric arc heating mode, can control laser beams in real time and has convenient operation. Meanwhile, the laser heating induction current heating mode is adopted to enable the interior of the weldment to generate current. Therefore, the whole of the interior and the surface of the weldment is heated, and the problem of internal and external temperature difference of the weldment does not exist;

3. according to the invention, the preheating welding device is provided with the accurate tracking and positioning sensor, so that the welding seam is visually identified, and the welding quality is improved;

4. the invention adopts the laser preheating welding device to replace electric arc welding, thereby improving the welding efficiency. After welding one welding seam, the next welding seam is positioned and then scanned, so that the welding work can be carried out, and the welding machine is very convenient.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic diagram of a laser preheating welding device for a 2219 aluminum alloy flat plate structure in an embodiment of the invention;

FIG. 2 is a schematic diagram of a method for laser preheating and welding small-size weldments and large-size weldments in an embodiment of the present invention;

FIG. 3 is a schematic overall view of a laser preheating welding device for a 2219 aluminum alloy flat plate butt joint structure in an embodiment of the present invention;

FIG. 4 is an overall schematic view of a laser preheating welding clamping device for a 2219 aluminum alloy flat plate butt joint structure in the embodiment of the invention;

the method comprises the following steps of 1-an optical fiber laser, 2-a semiconductor laser, 3-a temperature controller, 4-a driving power supply, 5-a laser preheating head, 6-a laser welding head, 7-an infrared temperature measuring sensor, 8-an accurate tracking and positioning sensor, 9-2219 aluminum alloy flat plate butt welding piece, 10-a base platform, 11-a height adjuster, 12-a positioning piece, 13-a large-force pressing rod, 14-a locking pin, 15-a semiconductor laser beam, 16-an optical fiber laser beam, 17-a welding line and 18-a preheating area.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Referring to fig. 1, 2, 3 and 4, fig. 1 is a schematic structural diagram of a laser preheating welding device in a specific embodiment of the present invention, fig. 2 is a schematic structural diagram of a laser preheating welding technology in the present invention, fig. 3 is a schematic overall diagram of a laser preheating welding device in the present invention, and fig. 4 is a schematic overall structural diagram of a laser preheating welding clamping device in a specific embodiment of the present invention.

A laser preheating welding device for laser welding aluminum alloy pre-welding preheating comprises the following steps:

in a specific implementation technical scheme, the invention provides a laser preheating welding device for laser welding aluminum alloy pre-welding, which comprises a preheating welding system and a welding platform, wherein the preheating welding system comprises a temperature controller for detecting a preheating semiconductor laser and a welding optical fiber laser, the outsides of the semiconductor laser and the optical fiber laser are respectively provided with a laser preheating head and a laser welding head for adjusting focal length and working distance to obtain a light spot with a proper size, the temperature controller utilizes cooling water to cool the laser and is externally provided with a driving power supply for controlling the laser to start, the welding platform is provided with a tool clamp for clamping a welding piece and a base platform for supporting the tool clamp, and the tool clamp can move relative to the base platform.

When the preheating welding device is applied, firstly, the welding seam of the workpiece is heated by thelaser preheating head 5 according to the route positioned by the accuratetracking positioning sensor 8, the temperature of the welding seam of the workpiece is monitored by the infraredtemperature measuring sensor 7, then, when the temperature of the welding seam reaches the welding requirement, the welding seam is welded by thelaser welding head 6, the temperature of the welding seam is monitored by the infraredtemperature measuring sensor 7, meanwhile, all welding seams are scanned by the accuratetracking positioning sensor 8, finally, one-time welding work is completed after the welding is performed by thelaser welding head 6 according to the route positioned by the accuratetracking positioning sensor 8, namely, one-time welding work is completed, and at the moment, the weldingoptical fiber laser 1 and the control system are stopped. And moving the accuratetracking positioning sensor 7, thelaser preheating head 5 and thelaser welding head 6 to the next welding line, and starting the next preheating welding operation.

Preferably, the preheating welding system comprises atemperature controller 3 for detecting the preheatingsemiconductor laser 2 and thewelding fiber laser 1, and an operator can judge whether the laser is in a normal working range according to the temperature value of the laser detected by thetemperature controller 3 so as to ensure the safety of the working.

Preferably, the preheating welding system comprises a drivingpower supply 4 for controlling the laser to start the preheatingsemiconductor laser 2 and thewelding fiber laser 1, and an operator can control the device to start in time so as to avoid generating faults and damaging equipment.

In order to further improve the precision degree of the preheating welding device, preferably, in the embodiment of the present invention, the preheating welding system further includes an infraredtemperature measurement sensor 7 for detecting the preheating temperature and the welding temperature of theweldment 9, and a precisiontracking positioning sensor 8 for visually recognizing the weld joint.

Preferably, the welding platform is provided with a tooling fixture for clamping theweldment 9 and abase platform 10 for supporting the tooling fixture, and the tooling fixture can move relative to thebase platform 10.

Preferably, the tooling fixture is provided with aheight adjuster 11 for controlling the clamping height, theheight adjuster 11 is sleeved on apositioning part 12 for fixing the position of theweldment 9, theheight adjuster 11 is longitudinally fixed with a large-force pressing rod 13 for pressing the weldment, and alocking pin 14 for screwing the large-force pressing rod is sleeved above the large-force pressing rod.

The application process of the laser preheating welding device for the rocket fuel storage tank provided by the specific implementation technical scheme of the invention is as follows:

firstly, setting a tool, fixing aweldment 9 to be welded at a set position, arranging tool fixtures supported by abase platform 10 around theweldment 9, pressing theweldment 9 by the tool fixtures, positioning a weld joint 17 of theweldment 9 before welding by using the accurate tracking andpositioning sensor 8, starting the infraredtemperature measurement sensor 7 to detect the temperature of the weld joint of theweldment 9, and enabling thelaser preheating head 5 and thelaser welding head 6 to correspond to the weld joint 17 positioned by the accurate tracking andpositioning sensor 8;

then, preheating a weldment, heating apreheating area 18 at awelding seam 17 of theweldment 9 by using a large-diameter light spotsemiconductor laser beam 15 generated by asemiconductor laser 2 according to a positioning route of the accuratetracking positioning sensor 8 by using thelaser preheating head 5, and monitoring the temperature at the welding seam of theweldment 9 by using the infraredtemperature measuring sensor 7;

welding a weldment, when the temperature of theweldment 9 meets the welding requirement, welding a welding seam by using an opticalfiber laser beam 16 emitted by alaser welding head 6, monitoring the temperature of the welding seam of theweldment 9 by using an infraredtemperature measuring sensor 7, scanning all welding seams by using a precise tracking andpositioning sensor 8, completing one welding operation after thelaser welding head 6 performs welding according to a path positioned by the precise tracking andpositioning sensor 8, then stopping the weldingoptical fiber laser 1 and a control system, and finally moving the precise tracking andpositioning sensor 8, thelaser preheating head 5 and thelaser welding head 6 to the next welding seam for preheating welding.

Therefore, the invention has the following beneficial effects:

the invention adopts a heating mode of laser induction current heating instead of surface heat conduction, so that weldments with different structures can be preheated and welded, and the applicability is strong.

The invention adopts a laser heating mode, has more accurate preheating range than an electric arc heating mode, can control laser beams in real time and is convenient to operate. Meanwhile, the laser heating induction current heating mode is adopted to enable the interior of the weldment to generate current. Thereby make inside and the whole heating in surface of weldment, so, the weldment does not have the problem of inside and outside difference in temperature.

According to the invention, the preheating welding device is provided with the accurate tracking and positioning sensor to visually identify the welding line, so that the welding quality is improved.

The invention adopts the laser preheating welding device to replace electric arc welding, thereby improving the welding efficiency. After welding one welding seam, the next welding seam is positioned and then scanned, so that the welding work can be carried out, and the welding machine is very convenient.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims (9)

1. A laser welding apparatus with a preheating function, characterized by comprising: preheating a welding system, a welding platform (10);

the preheat welding system includes: welding a fiber laser (1), a semiconductor laser (2), a laser preheating head (5) and a laser welding head (6);

the welding fiber laser (1) comprises: a temperature controller (3);

the temperature controller (3) can detect the temperature of the preheating semiconductor laser (2) and the welding optical fiber laser (1);

the temperature controller (3) can control the temperature of the welding fiber laser (1);

the semiconductor laser (2) and the optical fiber laser (1) are externally provided with a laser preheating head (5) and a laser welding head (6) which are used for adjusting focal length and working distance to obtain light spots with proper sizes;

the welding platform (10) is arranged at the lower part of the preheating welding system.

2. The laser welding apparatus with a preheating function according to claim 1, wherein the preheating welding system further includes: a drive power supply (4);

the temperature controller (3) can utilize cooling water to cool the laser, and is externally provided with a driving power supply (4) for controlling the laser to start.

3. The laser welding apparatus with a preheating function according to claim 1, characterized by further comprising: a weldment (9);

the preheat welding system further includes: an infrared temperature measurement sensor (7);

the infrared temperature measurement sensor (7) can be used for detecting the preheating temperature and the welding temperature of the weldment (9).

4. The laser welding apparatus with a preheating function according to claim 3, wherein the preheating welding system further comprises: a precise tracking and positioning sensor (8);

the accurate tracking and positioning sensor (8) can be used for visually identifying the welding seam.

5. The laser welding apparatus with a preheating function according to claim 1, characterized by further comprising: a control system;

the temperature controller (3), the driving power supply (4), the infrared temperature measuring sensor (7), the semiconductor laser (2), the welding fiber laser (1), the laser preheating head (5) and the laser welding head (6) are all connected to the control system.

6. The laser welding apparatus with a preheating function according to claim 1, characterized by further comprising: the device comprises a height adjuster (11), a positioning piece (12), a pressing rod (13) and a locking pin (14);

the positioning piece (12) can fix the position of the weldment (9);

the height adjuster (11) is nested in the positioning piece (12);

the pressing rod (13) can press the weldment (9);

the height adjuster (11) longitudinally fixes the pressing rod (13);

the locking pin (14) can be screwed to the clamping lever (13).

7. A preheating welding method, characterized in that the laser welding apparatus with preheating function according to any one of claims 1 to 6 is used, comprising:

step S1: setting a temperature controller for detecting the preheating semiconductor laser and the welding fiber laser;

step S2: arranging a laser preheating head and a laser welding head outside the semiconductor laser and the optical fiber laser for adjusting the focal length and the working distance to obtain light spots with proper sizes;

step S3: a temperature controller is adopted to cool the laser by using cooling water, and a driving power supply for controlling the laser to start is arranged outside the laser;

step S4: the welding fixture comprises a welding platform, wherein a tooling fixture for clamping the weldment and a base platform for supporting the tooling fixture are arranged on the welding platform, and the tooling fixture can move relative to the base platform.

8. The preheat welding method of claim 7, further comprising:

step S5: an infrared temperature measuring sensor for detecting the preheating temperature and the welding temperature of the weldment and an accurate tracking and positioning sensor for visually identifying the welding line are arranged in the preheating welding system.

9. The preheat welding method of claim 7, further comprising:

step S6: firstly, heating the welding seam of a weldment by a laser preheating head according to a route positioned by a precise tracking and positioning sensor, and monitoring the temperature of the welding seam of the weldment by using an infrared temperature measuring sensor;

step S7: when the temperature of the welding seam reaches the welding requirement, welding the welding seam by using the laser welding head, monitoring the temperature of the welding seam by using the infrared temperature measuring sensor, and scanning all the welding seams by using the accurate tracking and positioning sensor;

step S8: after welding is carried out by utilizing the laser welding head according to the route positioned by the accurate tracking positioning sensor, one welding work is finished, namely one welding work is finished, and at the moment, the welding of the optical fiber laser and the control system is stopped; and moving the accurate tracking and positioning sensor, the laser preheating head and the laser welding head to the next welding line, and starting to perform the next preheating welding operation.

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