Laser friction hybrid welding system and laser friction hybrid welding process

Abstract

The invention discloses a laser friction hybrid welding system and a laser friction hybrid welding process, and belongs to the field of welding. According to the technical scheme, the laser friction hybrid welding system comprises a laser module and a feeding module, the feeding module comprises a first feeding assembly and a second feeding assembly, the first feeding assembly comprises a first main shaft device, and the output end of the first main shaft device is connected with a first clamping device; the second feeding assembly comprises a second main shaft device and a linear driving device, the driving end of the linear driving device is connected with the second main shaft device, the output end of the second main shaft device is connected with a second clamping device, and the first clamping device directly faces the second clamping device; the laser module comprises a laser head, and the laser head is located above the position between the first clamping device and the second clamping device. According to the scheme, friction welding and laser welding are conducted synchronously, welding heat is guaranteed, workpieces are fully welded, meanwhile, due to the fact that the workpieces are heated through laser after abutting, the stability of the shapes of the workpieces is guaranteed, and the problems of flash and the like are solved.

Description

Technical Field

[0001] The invention relates to the field of welding, in particular to a laser friction composite welding system and a laser friction composite welding process. Background Art

[0002] Friction welding is a solid-state welding technology mainly used for joining metal materials. Its working principle is that two workpieces rotate relative to each other under axial pressure, and the friction between the interfaces generates heat, which heats the metal to a plastic state. Then, under the action of pressure, the rotation is stopped and forging pressure is applied. The thermal-mechanical coupling causes element diffusion and organizational phase change at the interface, so that the joint forms a tight metallurgical bond.

[0003] In the above process, the heat source between the two workpieces is completely provided by frictional heat. When welding coarse and thick workpieces, the frictional heat in the joint end faces of the workpieces gradually decreases from the rotation center to the outside, which easily leads to defects such as unwelded and uneven texture.

[0004] Laser processing can rapidly heat up the workpiece through high-energy lasers to achieve the effects of melting and vaporization. Taking advantage of this feature, laser assistance is sometimes introduced in rotary friction welding, such as Figure 1 As shown, the current method is to irradiate the end faces of the two workpieces with lasers before the end faces of the workpieces contact during the axial feeding of the friction welding, so as to quickly heat up the end faces of the workpieces to compensate for the problem of insufficient heat generated by friction.

[0005] The shortcomings of the current laser-assisted rotary friction welding process are: the laser power cannot be too high or the irradiation time cannot be too long, otherwise it will cause excessive melting of the workpiece end face substrate, resulting in workpiece deformation and a large amount of flash during welding extrusion; and the laser input energy is controlled at a low level. Before the two workpiece end faces come into contact, the heated workpiece end faces will cause a sudden drop in temperature due to high-speed rotation in the air. During the welding process, the main energy is still friction heat, and the effect of laser-assisted heating is limited. Summary of the invention

[0006] The present invention aims at the problem that insufficient heat in current rotary friction welding and laser-assisted rotary friction welding affects welding quality, and provides a laser friction composite welding system.

[0007] To solve the above problems, the technical solution adopted by the present invention is a laser friction composite welding system, including a laser module and a feeding module, the feeding module includes a first feeding assembly and a second feeding assembly, the first feeding assembly includes a first spindle device, the output end of the first spindle device is connected to a first clamping device; the second feeding assembly includes a second spindle device and a linear drive device, the driving end of the linear drive device is connected to the second spindle device, the output end of the second spindle device is connected to a second clamping device, and the first clamping device is directly opposite to the second clamping device; the laser module includes a laser head, and the laser head is located above the line between the first clamping device and the second clamping device. The welding system of this scheme clamps two workpieces respectively by the first clamping device and the second clamping device, rotates the two workpieces by the first spindle device and the second spindle device, and the linear drive device performs axial feeding. After the two workpieces contact, the laser irradiates the joint and heats the outer edge of the workpiece. This scheme allows friction welding and laser welding to be performed simultaneously, ensuring sufficient welding heat and fully fusing the workpieces. At the same time, due to the laser heating after the workpieces collide, the shape of the workpiece is guaranteed to be stable, and the problems such as flash are reduced.

[0008] As a preferred embodiment of a laser friction hybrid welding system, the output end of the first spindle device is connected to a first flywheel through a clutch, and the first clamping device is mounted on the first flywheel, and / or, the output end of the second spindle device is connected to a second flywheel through a clutch, and the second clamping device is mounted on the second flywheel. When the workpieces are in contact welding, the power input of the spindle device can be cut off by the clutch, so that the flywheel inertia drives the workpiece to rotate, which can better adapt to the speed synchronization during the workpiece welding process, eliminate the reverse torque on the spindle device, protect the equipment and improve the welding quality, reduce the speed control requirements for the spindle device, and facilitate program debugging and operation.

[0009] As a preferred embodiment of the laser friction hybrid welding system, it also includes a main machine bed, the first spindle device and the linear drive device are fixedly mounted on the main machine bed, the main machine bed is also provided with a guide rail, a movable slide is slidably mounted on the guide rail, and the second clamping device is mounted on the movable slide. The second spindle device is mounted on the main machine bed through the guide rail, and the guide rail guides the feeding direction, which is suitable for high thrust occasions and improves the feeding accuracy.

[0010] As a preferred embodiment of the laser friction hybrid welding system, the first clamping device includes a first spring sleeve and a first clamping hydraulic cylinder for driving the first spring sleeve; the second clamping device includes a second spring sleeve and a second clamping hydraulic cylinder for driving the second spring sleeve. The spring sleeve is used to clamp the workpiece, and the workpiece can be easily and quickly disassembled.

[0011] As a preferred embodiment of a laser friction hybrid welding system, the laser module further includes an axial motion component, the laser head is mounted on the axial motion component, and the axial motion component can at least drive the laser head to move in the opposite direction of the first clamping device and the second clamping device. The position of the laser head can be adjusted to adapt to workpieces of different lengths, and the laser position can also be offset. It can not only be placed on the interface of the workpiece, but also can be rotated at multiple angles. It is not affected by the placement position of the workpiece, the process parameters of the rotary friction welding, etc. It can be applied to any position of the interface between the two workpieces. At the same time, the weld quality can be improved by adjusting the position of the laser heat source, which is also applicable to fillet welding.

[0012] On the other hand, the present invention also provides a laser friction composite welding process, comprising the following steps: S1. Clamp the first workpiece on the first clamping device and clamp the second workpiece on the second clamping device; S3. The first spindle device drives the first workpiece to rotate at a first speed, and the second spindle device drives the second workpiece to rotate at a second speed; S3. The linear drive device drives the second spindle device to move closer to the first spindle device; S4. When the end surface of the first workpiece contacts the end surface of the second workpiece, the laser head projects a laser, and the laser continuously irradiates the bonding interface between the first workpiece and the second workpiece; S5. The linear drive device drives the second spindle device to continue to apply top pressure to the second workpiece in the direction of the first spindle, and the first workpiece and the second workpiece are welded and fused; S6. Turn off the laser module and the feeding module.

[0013] This process places the laser heat source at the interface between the two workpieces. Compared with single rotary friction welding, it provides additional heat input when welding larger-sized bars, which increases the heat input at the interface between the two workpieces and transforms it into an incomplete solid-phase connection, promoting material fluidity, facilitating the formation of metallurgical bonding, reducing defects such as incomplete penetration, and thereby improving the mechanical properties of the welded joint.

[0014] As a preferred implementation of the laser friction hybrid welding process, in step S4 and step S5, the periphery of the bonding area between the first workpiece and the second workpiece is in a molten state, and the interior is in a molten state.

[0015] As a preferred implementation scheme of the laser friction composite welding process, in step S3, the first spindle device drives the first flywheel to rotate, the first flywheel drives the first clamping device to rotate, and when the speed of the first flywheel reaches the first speed, the first spindle device is disengaged from the first flywheel. When the workpieces are in contact welding, the power input of the spindle device can be cut off by the clutch, so that the flywheel inertia drives the workpiece to rotate, which can better adapt to the speed synchronization during the workpiece welding process, eliminate the reverse torque on the spindle device, protect the equipment and improve the welding quality, reduce the speed control requirements for the spindle device, and facilitate program debugging and operation.

[0016] As a preferred implementation of the laser friction hybrid welding process, in step S4, when the first workpiece and the second workpiece are made of different materials, the laser head moves a distance x, 0 < x ≤ 200 mm, toward the workpiece with a lower softening degree through the axis motion system, so that the first workpiece and the second workpiece are at the same softening degree. The laser position is adjustable, which is flexible and convenient.

[0017] As a preferred embodiment of the laser friction hybrid welding process, the zero focus of the laser head is located at the edge of the bonding interface between the first workpiece and the second workpiece.

[0018] It can be seen from the above technical aspects that the advantages of the present invention are: 1. The present invention places the laser heat source at the interface between the two workpieces, which provides additional heat input when welding larger-sized bars compared to single rotary friction welding, thereby increasing the heat input at the interface between the two workpieces and converting it into an incomplete solid-phase connection, promoting material fluidity, facilitating the formation of metallurgical bonding, reducing defects such as incomplete penetration, and thereby improving the mechanical properties of the welded joint.

[0019] 2. In the present invention, the first workpiece is rotated by the spindle system, and the second workpiece is fed toward the first workpiece by the upset forging system. When the second workpiece contacts the rotating first workpiece, the laser heat source is started to increase the heat input at the interface between the first workpiece and the second workpiece.

[0020] 3. The laser heat source used in the present invention is highly flexible. It can not only be placed on the interface between the first workpiece and the second workpiece, but also can be rotated at multiple angles. It is not affected by the placement of the workpieces, the rotary friction welding process parameters, etc. It can be applied to any position of the interface between the two workpieces. At the same time, the weld quality can be improved by adjusting the position of the laser heat source, and it is also suitable for fillet welding.

[0021] 4. The present invention uses laser welding for compounding. Compared with other welding methods, such as MIG welding, TIG welding and other welding methods, it does not require wire feeding, has a small heat-affected zone, and does not produce spatter during welding, and can accurately control the welding position. Rotary friction welding has a small heat input and does not have defects such as pores and slag inclusions that occur in fusion welding.

[0022] 5. The present invention is suitable for butt welding of bars, which is beneficial to improving the welding quality of bars with larger diameters, and the laser position is adjustable, which is flexible and convenient.

[0023] 6. The present invention applies a laser heat source during the welding process. Compared with the use of laser heating in advance, the heat source of the entire process is relatively stable, the heat transferred from the laser to the weld will not decrease over time, and there is no need to change the shape and size of the laser beam spot considering the thickness of the workpiece.

[0024] 7. The present invention utilizes a combination of laser welding and rotary friction welding. The laser heating area is small in size, and a large area of ​​the periphery of the workpiece will not melt. The heat is transferred to the inside of the workpiece, so that the workpiece quickly reaches a molten state and achieves connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0026] Figure 1 It is a schematic diagram of the principle of laser-assisted friction welding in the prior art.

[0027] Figure 2 It is a schematic diagram of the structure of embodiments 1 and 2 of the present invention.

[0028] Figure 3 It is a schematic diagram of the end face state of a workpiece in the second embodiment of the present invention.

[0029] Description of main reference numerals 1. The first spindle device, 2. The first flywheel, 3. The first clamping hydraulic cylinder, 4. The first spring sleeve, 5. The first workpiece, 6. The second workpiece, 7. The laser head, 8. The second spring sleeve, 9. The second spindle device, 10. The linear drive device, 11. The guide rail, 12. The main machine bed, 13. The second clamping hydraulic cylinder, 14. The second flywheel. DETAILED DESCRIPTION

[0030] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0031] Embodiment 1 like Figure 2 As shown, a laser friction composite welding system includes a main machine bed 12, on which a laser module and a feed module are provided: The laser module includes an axial motion component, on which a laser head 7 is mounted. The axial motion component can adopt a structure similar to that of a laser cutting machine, that is, it includes a balance beam and a head module that can move along the beam (x-axis direction). The head module includes a slide that can move in the vertical direction (z-axis direction), and the laser head 7 is mounted on the slide. This is a common structure in the field of laser processing and will not be repeated here.

[0032] The feed module includes a first feed component and a second feed component. The first feed component includes a first spindle device 1, which is fixedly mounted on a main machine bed 12. The first spindle device provides rotational power for the workpiece and can use a rotary motor. The output end of the first spindle device 1 is connected to a first clamping device, which includes a first spring sleeve 4 and a first clamping hydraulic cylinder 3 for driving the first spring sleeve 4. After the workpiece is loaded into the first spring sleeve 4, the first clamping hydraulic cylinder retracts to allow the first spring sleeve to clamp the workpiece.

[0033] The second feed assembly includes a second spindle device 9 and a linear drive device 10, the linear drive device 10 is fixedly mounted on the main machine bed 12, the main machine bed 12 is also provided with a guide rail 11, a movable slide is slidably mounted on the guide rail 11, the second spindle device 9 is mounted on the movable slide, the driving end of the linear drive device 10 is connected to the second spindle device 9, the output end of the second spindle device 9 is connected to the second clamping device, the second clamping device includes a second spring sleeve 8 and a second clamping hydraulic cylinder 13 for driving the second spring sleeve 8, after the second workpiece is inserted into the second spring sleeve 8, the second clamping hydraulic cylinder 13 retracts to drive the second spring sleeve 8 to clamp the second workpiece, and the linear drive device 10 can adopt a friction welding upset forging device.

[0034] The first clamping device and the second clamping device are arranged opposite to each other, and the laser head 7 is located above the line between the first clamping device and the second clamping device (the line is along the y-axis direction).

[0035] In other embodiments, the clamping device may also be in the form of a chuck, and the layout of the first clamping device and the second clamping device may also be vertical (horizontal in this embodiment), and the laser head may be correspondingly arranged horizontally.

[0036] Embodiment 2 like Figure 2As shown, in this embodiment, the output end of the first spindle device 1 is connected to the first flywheel 2 through a clutch, and the first clamping device is installed on the first flywheel 2; the output end of the second spindle device 9 is connected to the second flywheel 14 through a clutch, and the second clamping device is installed on the second flywheel 14.

[0037] Embodiment 3 Based on the welding systems provided in the first and second embodiments, this embodiment further provides a laser friction composite welding process, including the following steps: S1. First, the end faces of the first workpiece 5 and the second workpiece 6 to be welded are polished to remove the oxide film and oil stains to expose the metal surface luster, and then the first workpiece 5 is clamped on the first clamping device, and the second workpiece 6 is clamped on the second clamping device. Specifically, the workpieces are loaded into the spring sleeve, and the spring sleeve is driven by the clamping hydraulic cylinder to clamp the workpieces; S3. The first spindle device 1 drives the first workpiece 5 to rotate at a first speed, and the second spindle device 9 drives the second workpiece 6 to rotate at a second speed; S3. The linear drive device 10 drives the second spindle device 9 to approach the first spindle device 1; S4. When the end surface of the first workpiece 5 contacts the end surface of the second workpiece 6, the laser head 7 projects a laser, and the laser continuously irradiates the bonding interface of the first workpiece 5 and the second workpiece 6, and the zero focus of the laser head 7 is located at the edge of the bonding interface of the first workpiece 5 and the second workpiece 6; S5. The linear drive device drives the second spindle device to continue to apply top pressure to the second workpiece in the direction of the first spindle, and the first workpiece 5 and the second workpiece 6 are welded and fused; S6. After the connection is achieved, turn off the laser module first, then turn off the feed module, and remove the welded workpiece from the spring sleeve.

[0038] like Figure 3 As shown, in step S4 and step S5, the periphery of the bonding area of ​​the first workpiece 5 and the second workpiece 6 is in a molten state, and the interior is in a molten state. In this process, the complete solid phase welding is converted to the local melting solid phase welding. The laser head directly acts on the edge area of ​​the first workpiece and the bottom workpiece where the heat generation is less and the plastic flow is poor, thereby increasing the edge temperature of the first workpiece and the second workpiece, enhancing the flow performance of the material, and improving the mixing degree of the material, which is beneficial to the metallurgical bonding between the first workpiece and the second workpiece, reducing the defects of the thicker diameter rod rotation friction welding and the like, and improving the mechanical properties of the weld joint.

[0039] In step S4, when the first workpiece 5 and the second workpiece 6 are made of different materials, the laser head moves a distance x, 0<x≤200mm, toward the workpiece with a lower softening degree through the axis motion system, so that the first workpiece and the second workpiece are at the same softening degree, thereby making the material flow evenly.

[0040] For the second embodiment, in step S3, the first spindle device 1 drives the first flywheel 2 to rotate, and the first flywheel 2 drives the first clamping device to rotate. When the rotation speed of the first flywheel 2 reaches the first rotation speed, the first spindle device 1 is disengaged from the first flywheel 2.

[0041] In the above process, the laser head 7 can be a continuous laser or a pulsed laser, and the heat input of the laser head can be accurately controlled to prevent large heat input from causing melting defects on the weld surface, increase the fluidity of the material, and improve the weld surface forming. The power of the laser head 7 is 1W-50000W; the speed at which the second workpiece feeds the first workpiece can be adjusted by the upsetting force applied by the upsetting system, which is related to the diameter of the rod. The workpiece rod diameter ranges from 10mm to 500mm.

[0042] Compared with pre-heating the two workpiece ends, the heat input during the entire welding process is not the same. If the two workpiece ends are heated in advance, before the two workpiece ends come into contact, the heated workpiece ends will drop sharply in temperature due to being in the air. Therefore, the main energy during the welding process is still friction heat, that is: Q=

[0043] After the two workpieces come into contact, a laser beam is applied above the contact interface of the two workpieces as an auxiliary heat source. The total heat in the whole process should be: Q 总 = +Q 激光 It can be seen from the above embodiments that the beneficial effect of the present invention is that the laser heat source is applied to the bonding interface of the two workpieces to enhance the heat input of the rotary friction welding. This method achieves incomplete solid-phase connection by increasing the heat input of the bonding interface when welding larger-sized bars, thereby promoting the fluidity of the material, helping to form a metallurgical bond, and reducing defects such as incomplete penetration, significantly improving the mechanical properties of the welded joint. In this technology, the first workpiece is rotated by a spindle system, and the second workpiece is fed to the first workpiece by an upsetting system. When the second workpiece contacts the rotating first workpiece, the laser heat source is started, further increasing the heat input of the bonding interface of the two workpieces. The laser heat source of the present invention has high flexibility. It can not only be placed on the bonding interface of the two workpieces, but also can be rotated at multiple angles. It is not limited by the placement position of the workpieces and the process parameters of the rotary friction welding. The heat source can be applied at any position, and the weld quality can be improved by adjusting the laser position. It is also suitable for fillet welding. Compared with traditional welding methods such as MIG welding and TIG welding, the present invention does not require wire feeding, has a small heat-affected zone, and does not generate spatter during welding. The welding position can be precisely controlled, and since the heat input of rotary friction welding is small, defects such as pores and slag inclusions in melting welding will not occur. This technology is particularly suitable for butt welding of bars, especially bars with larger diameters, and can improve the welding quality. The laser position is adjustable, and the operation is flexible and convenient. Applying a laser heat source during the welding process is more stable than using laser heating in advance. The heat transferred from the laser to the weld will not decrease over time, and there is no need to adjust the spot shape and size of the laser beam according to the thickness of the workpiece. The present invention combines laser welding with rotary friction welding. Since the laser heating area is small, there will be no large-scale melting of the periphery of the workpiece. The heat is mainly transferred to the inside of the workpiece, so that the workpiece quickly reaches a molten state and an effective connection is achieved.

[0044] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A laser friction hybrid welding system, comprising a laser module and a feed module, characterized in that: The feeding module comprises a first feeding assembly and a second feeding assembly, the first feeding assembly comprising a first spindle device (1), the output end of the first spindle device (1) being connected to a first clamping device; the second feeding assembly comprising a second spindle device (9) and a linear drive device (10), the driving end of the linear drive device (10) being connected to the second spindle device (9), the output end of the second spindle device (9) being connected to a second clamping device, the first clamping device being directly opposite to the second clamping device; The laser module comprises a laser head (7), and the laser head (7) is located above the line connecting the first clamping device and the second clamping device.

2. The laser friction hybrid welding system according to claim 1, characterized in that: The output end of the first spindle device (1) is connected to a first flywheel (2) via a clutch, and the first clamping device is mounted on the first flywheel (2); and / or the output end of the second spindle device (9) is connected to a second flywheel (14) via a clutch, and the second clamping device is mounted on the second flywheel (14).

3. The laser friction hybrid welding system according to claim 1, characterized in that: It also includes a main machine bed (12), the first spindle device (1) and the linear drive device (10) being fixedly mounted on the main machine bed (12), the main machine bed (12) also being provided with a guide rail (11), a movable slide being slidably mounted on the guide rail (11), and the second spindle device (9) being mounted on the movable slide.

4. The laser friction hybrid welding system according to claim 1, characterized in that: The first clamping device comprises a first spring sleeve (4) and a first clamping hydraulic cylinder (3) for driving the first spring sleeve (4); the second clamping device comprises a second spring sleeve (8) and a second clamping hydraulic cylinder (13) for driving the second spring sleeve (8).

5. The laser friction hybrid welding system according to claim 1, characterized in that: The laser module further comprises an axial motion component, the laser head (7) is mounted on the axial motion component, and the axial motion component is at least capable of driving the laser head (7) to move in a direction facing the first clamping device and the second clamping device.

6. A laser friction composite welding process, characterized in that: The following steps are involved: S1. Clamping a first workpiece (5) on a first clamping device, and clamping a second workpiece (6) on a second clamping device; S3. The first spindle device (1) drives the first workpiece (5) to rotate at a first speed, and the second spindle device (9) drives the second workpiece (6) to rotate at a second speed; S3. The linear drive device (10) drives the second spindle device (9) to move closer to the first spindle device (1); S4. When the end surface of the first workpiece (5) contacts the end surface of the second workpiece (6), the laser head (7) projects a laser, and the laser continuously irradiates the bonding interface between the first workpiece (5) and the second workpiece (6); S5. The linear drive device drives the second spindle device to continue to apply a top pressure to the second workpiece in the direction of the first spindle, and the first workpiece (5) and the second workpiece (6) are welded and fused; S6. Turn off the laser module and the feeding module.

7. The laser friction hybrid welding process according to claim 6, characterized in that: In the steps S4 and S5, the outer periphery of the bonding area of ​​the first workpiece (5) and the second workpiece (6) is in a molten state, and the inner part is in a molten state.

8. The laser friction hybrid welding process according to claim 6, characterized in that: In step S3, the first spindle device (1) drives the first flywheel (2) to rotate, and the first flywheel (2) drives the first clamping device to rotate. When the rotation speed of the first flywheel (2) reaches a first rotation speed, the first spindle device (1) is disengaged from the first flywheel (2).

9. The laser friction hybrid welding process according to claim 8, characterized in that: In step S4, when the first workpiece (5) and the second workpiece (6) are made of different materials, the laser head is moved by the axis motion system toward the workpiece with a lower softening degree by a distance x, 0<x≤200mm, so that the first workpiece and the second workpiece are at the same softening degree.

10. The laser friction hybrid welding process according to claim 8, characterized in that: The zero focus of the laser head (7) is located at the edge of the bonding interface between the first workpiece (5) and the second workpiece (6).

Images