CN111872559B

CN111872559B - Laser welding device and working method thereof

Info

Publication number: CN111872559B
Application number: CN202010775063.XA
Authority: CN
Inventors: 周超
Original assignee: Changsha Chenzi Automation Technology Co ltd
Current assignee: Changsha Chenzi Automation Technology Co ltd
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2022-05-13
Anticipated expiration: 2040-08-05
Also published as: CN111872559A

Abstract

The invention relates to a laser welding device and a working method thereof, belonging to the field of laser welding. The welding device is mainly used for solving the problems that welding defects are easily caused due to small laser spots caused by workpiece production errors in the tailor welding and fillet welding of laser, and welding wires are easily deviated from an original molten pool to cause the welding defects and the like in the laser wire feeding welding. The laser welding device consists of two parts, namely a light path part and a welding wire swinging mechanism part. In the light path part, laser passes through the collimating mirror and is projected to the house-shaped reflecting mirror, and then is focused by the parabolic focusing mirror to form double-strip-shaped laser spots. And in the light path part, the lens is fully water-cooled, so that the lens is very suitable for high-power laser output. The welding wire swing mechanism mainly comprises a driving motor, an upper swing arm, a lower swing arm, a wire feeding fixed block and the like.

Description

Laser welding device and working method thereof

Technical Field

The invention relates to the field of laser welding, in particular to laser tailor-welding, fillet welding and laser wire feeding welding.

Background

With the development of laser, high-power laser welding is widely applied in industry, and particularly laser tailor welding, fillet welding and laser wire feeding welding are widely applied in the fields of automobiles, shipbuilding, aerospace, mines and the like. Such as unequal thick plate welding in automobiles, thick plate welding in shipbuilding, titanium plate welding in aerospace and the like.

At present, because laser spots of a laser welding light path are smaller relative to a splicing seam system, even if thick-core-diameter optical fibers are selected for transmission, welding defects are very easily generated in laser splicing welding, fillet welding and wire feeding welding applications. In laser tailor-welding, gaps are easily generated in butt joint of tailor-welded workpieces due to manufacturing errors of the workpieces. When a laser is used for welding such a workpiece, defects such as missing welding or weld recess are very likely to occur, and fillet welding is also similar to this. In the laser wire feeding welding, the wire feeding path and the laser track have slight deviation, the welding effect is defective, and the welding quality can not meet the requirement.

Based on the defects easily generated in the welding process, the method has the following advantages that: 201811204834.9 the problem of large production defect of welding workpiece gap is solved by using the vibrating mirror scanning device to replace a straight welding line. Chinese patent application No.: 201910925437.9 also adopts galvanometer welding to solve the limitation in laser welding. The method of utilizing the galvanometer scanning to solve the defects easily caused by small light spots in the laser welding can be summarized as a method of utilizing the laser swing to solve the problems in the laser welding. The existing laser-combined wire feeding welding is generally to directly feed a welding wire into a molten pool of a spot of a point or into a molten pool scanned by a laser galvanometer. The characteristic of this method is that the laser is a spot or a scanning spot, and the welding wire is fed along the track.

Disclosure of Invention

The invention aims to provide a simple, convenient and stable laser welding device, and aims to solve the technical problems that in the prior art, laser tailor-welding, fillet welding and laser wire feeding welding are easy to generate limitation or defects due to poor work of workpieces or relatively small light spots and the like.

The technical scheme includes that the laser welding device can convert laser emitted by a laser into double-strip-shaped light spots to be projected on a processing surface, and a welding wire is fed into a molten pool in a swinging mode to be used for laser welding. The laser welding device is divided into two parts, a laser light path part and a welding wire swinging mechanism. The laser light path part comprises a collimating mirror, a CCD monitoring device, a house type reflecting mirror, a parabolic focusing mirror, a focusing protective mirror and the like. The collimating mirror converts the light beam into parallel light beam, and the parallel light beam is thrown into the room-type reflecting mirror, the room-type reflecting mirror is arranged below the collimating mirror and is arranged at an angle of 45 degrees with the light path of the collimating mirror, the thrown parallel light is reflected into two symmetrical partial lights, the center of the room-type reflecting mirror and the center of the collimating mirror are on the same axis, the parabolic focusing mirror and the room-type reflecting mirror are arranged in parallel in a mode of facing the surface of the room-type reflecting mirror, and the laser light reflected by the room-type reflecting mirror is focused on the processing surface to form double strip-shaped light spots. The welding wire swing mechanism mainly comprises a mounting plate, a driving motor, an upper swing arm, a lower swing arm, a welding wire fixing block and the like, wherein the driving motor is connected with the upper swing arm, the lower swing arm is embedded in the upper swing arm, and the driving motor drives the swing arm to drive the welding wire to do reciprocating motion in the laser bar-shaped light spots.

Further: the collimating mirror is arranged below the optical fiber and above the house-shaped reflecting mirror, and the protecting mirror is arranged above the collimating mirror to protect the collimating mirror. The center of the collimation lens, the center of the core diameter of the optical fiber and the center of the room-type reflection lens are on the same axis.

Further: the CCD spectroscope in the CCD device is arranged below the collimating mirror, and the vision is transmitted into the CCD camera through the CCD transmission device.

Further: the house type reflector is arranged below the collimating mirror and is arranged at an angle of 45 degrees with a light beam penetrating through the collimating mirror, the house type reflector is an elliptical mirror surface, the elliptical mirror surface consists of two symmetrical elliptical half surfaces, the two symmetrical elliptical half surfaces are symmetrically distributed on two sides of an elliptical long axis similar to two surfaces of a house, and the two elliptical half surfaces and the corresponding elliptical mirror surface form an angle smaller than 1 degree. The room-type reflector is arranged on the lens mounting seat, the back surface of the room-type reflector is provided with two interfaces, and a water inlet interface and a water return interface form a circulating water path with the outside.

Further: the parabolic focusing mirror is installed opposite to the roof-type reflecting mirror surface, the angle between the parabolic focusing mirror and the incident direction of a light path reflected by the roof-type reflecting mirror is 45 degrees, the parabolic focusing mirror is installed on the lens installation seat, and after receiving laser, the parabolic focusing mirror reflects and focuses the laser on a processing surface to form two symmetrical bilinear light spots.

Further: the welding wire swing mechanism comprises a driving motor, an upper swing arm, a lower swing arm, a welding wire fixing block and the like. The driving motor is in key connection with the upper swing arm, the lower swing arm is sleeved in the upper swing arm and is pressed tightly by the spring device, the spring device is mainly used for preventing the lower swing arm from colliding, and the wire feeding fixing block is connected with the lower swing arm.

Further: the driving motor drives the swing arm, the swing arm reciprocates to enable the welding wire to swing left and right in the double-strip laser facula for welding, and the swing amplitude of the welding wire is smaller than the width of the double-strip laser facula.

Drawings

Fig. 1 is a schematic structural diagram of a welding device according to a preferred embodiment of the present invention, showing the external structural components of the welding device.

Fig. 2 is a cross-sectional view of a welding apparatus according to a preferred embodiment of the present invention, mainly illustrating the components in the optical path and the projection path of the optical path.

Fig. 3 is a schematic structural diagram of a roof mirror according to a preferred embodiment of the present invention, mainly illustrating the external profile and main features of the roof mirror.

Fig. 4 is a schematic diagram of the laser and wire feeding tracks of the welding device of the present invention, mainly illustrating the relationship between the wire feeding track and the laser track.

Detailed Description

The following description of the preferred embodiments of the present invention will be provided in conjunction with the accompanying drawings to describe the technical solutions of the present invention in detail, but not to limit the present invention to the scope of the embodiments described.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1, fig. 2 is an external schematic view and a cross-sectional view of a laser welding apparatus according to a preferred embodiment of the invention. In the welding device, an optical fiber laser interface 101, a collimating protective lens mounting module 102 and a collimating lens mounting module 103 are arranged. The collimation protection lens installation module 102 is horizontally provided with a collimation protection lens 104 shown in the figure 2, the collimation protection lens 104 is installed in the collimation protection lens installation module 102 through a drawer type, and the collimation protection lens installation module 102 is provided with a temperature sensor which can sense the temperature of the protection lens in a contact manner and transmit the temperature to an external control unit. The collimating mirror 105 shown in fig. 2 is horizontally installed in the collimating mirror installing module 103, and the collimating mirror 105 is fixed in the collimating mirror installing module 103 through a copper pressing ring. The collimating protective lens 104 is installed below the optical fiber and above the collimating lens 105, and the collimating protective lens module 102 is above the collimating lens installing module 103. The collimating protective lens 104 has a protective effect on the collimating lens 105, and effectively prevents various contaminations of the collimating lens 105 in the optical fiber plugging process. The laser of the laser welding device is transmitted to the device through an optical fiber 300, and the laser passes through the collimating protective lens 104 and is transmitted to the collimating lens 105. The collimating lens 105 is an aspheric lens, and laser emitted by the optical fiber is changed into parallel beams after passing through the collimating lens 105. The collimating protective lens and the collimating lens are made of quartz or K9. In other embodiments, the laser light is transmitted through the optical fiber to the welding device and collimated by the mirror focusing mirror, so that the laser light is not required to be installed in parallel, but only transmitted to the center of the mirror surface, the collimating mirror is installed in a face-to-face manner with the roof, and the collimating mirror forms an angle of 45 degrees with the incident direction and the reflecting direction of the laser light.

In this embodiment, the CCD spectroscope 114 is mounted in the CCD mounting block 111 shown in fig. 1, and the welding line can be clearly observed by the CCD camera 112 via the CCD transfer device 113.

In the embodiment, the roof mirror 120 shown in fig. 1 is located right below the collimator 105, and the parallel laser beams from the collimator 105 are projected onto the roof mirror 120. In fig. 2, after being reflected by the room-type reflector 120, the light beam is spread along two sides of the room-type reflector 120 along the symmetrical axis, and the spreading angle corresponds to two surfaces of the room-type reflector and the mirror surface of the room-type reflector. The roof mirror 120 is mounted on the mirror mounting base 140 at an oblique angle of 45 degrees with respect to the incident direction of the laser beam axis. In the present embodiment, the lens mounting base 140 is an integral structure, the middle of the lens mounting base is hollow, one end of the lens mounting base is provided with the room-type reflector 120, the other end of the lens mounting base is provided with the parabolic focusing mirror 150, and the room-type reflector 120 and the parabolic focusing mirror 150 are fixed on the lens mounting base 140 by bolts and positioning pins. After the laser is reflected by the room-type reflector 120, the light beam passes through the inner hole of the lens mounting base 140 and is projected to the parabolic focusing mirror 150, the parabolic focusing mirror 150 is mounted face to face with the room-type reflector 120 and is parallel to the room-type reflector 120, so that the laser can be incident on the parabolic focusing mirror 150 at 45 degrees after passing through the room-type reflector 120. The light beam is focused by the parabolic focusing mirror 150, and forms double-strip-shaped light spots through the protective condenser 171, and the formed double-strip-shaped light spots are perpendicular to the major axis of the mirror surface ellipse of the room-type reflecting mirror 120. The focusing protective lens 171 is mounted on the protective lens base 160 to prevent welding slag and smoke from contaminating the light path during welding.

In this embodiment, the room mirror 120 is an elliptic mirror, and the elliptic mirror of the room mirror shown in fig. 3 is further divided into two semielliptic surfaces, which are symmetrical to each other along the major axis of the ellipse, are inclined to each other, and form an angle of not more than 1 degree with the mirror, similar to two surfaces of a room, depend on each other, and are inclined to each other. In other embodiments, the two halves of the roof mirror may be symmetrical along the minor axis of the ellipse, or symmetrical along the oblique line of symmetry of the ellipse.

In this embodiment, the cooling module 130 in fig. 1 is a water path cooling module, which has a cooling tank inside for supplying cooling water, and has two water path interfaces with the outside, one path for water supply and one path for water return. A contact cooling collimation protective lens 104, a collimation lens 105 and a CCD spectroscope 114. In the room-type reflector 120, the parabolic focusing mirror 150 is made of copper or aluminum, cooling grooves are formed in the lenses, two connectors are arranged on the back of each lens, one connector is used for water inlet, and the other connector is used for water return. The optical fiber cooling port, the cooling module 130, the room reflector 120 and the parabolic focusing mirror 150 form a series water path.

The side blowing device 170 is installed on the protective lens base 160, the air blowing port of the side blowing device 170 is in a horizontal line belt shape, the two pieces are separately packaged, the inner piece and the outer piece are fixed by bolts, and the high-pressure air of the side blowing device 170 effectively protects the focusing protective lens 171 from being polluted. The material of the side blowing device is copper material.

In the present embodiment, the driving motor 182 of the wire swinging mechanism is mounted on the fixing plate 183 together with the lens mount 140. The drive motor 182 is above the lens mount 140 while the fixing plate 183 is connected to the flange 200.

The servo motor 182 drives the swing arm to swing, and the swing arm is composed of an upper swing arm 184 and a lower swing arm 185. The lower swing arm 185 is nested in the upper swing arm 184, the lower swing arm 185 is pressed through the spring 188, when the swing arm 185 collides with a welding workpiece, the spring 188 can play a role in buffering, the lower swing arm is positioned through the round pin, the round pin is fixed in the upper swing arm, after collision occurs, the lower swing arm can be quickly recovered through the round pin, meanwhile, a sensor (not marked in the figure) is arranged on the side face of the lower swing arm 185, and when the lower swing arm collides, the sensor can immediately send a signal to the outside. The wire feed nozzle 187 is secured in the wire feed fixture 186. The wire feed nozzle 187 can be adjusted forward and backward, left and right, in the wire feed fixing block 186. The wire feeding fixing bracket 181 is fixed on the fixing plate 183 to support the wire tube. The drive motor 182 reciprocates the swing arm side-to-side, which drives the feed nozzle 187 to reciprocate the wire 188 under the laser spot while the external wire feeder drives the wire into the weld pool.

The invention also comprises a working method of the welding device, which mainly comprises the following steps.

S1, inserting the welding device into the optical fiber, connecting the optical fiber with the laser, and ensuring that the water path and the air path are normal.

S2 spot with low power. A stainless steel sheet is prepared, and a laser beam is emitted at a low power of usually 500W or less, leaving a laser stripe spot on the steel sheet.

And S3, adjusting the CCD camera to observe the light spots, and adjusting the CCD according to the positions of the light spots to enable the crosshair in the CCD camera to be aligned to the centers of the light spots.

S4, the left and right positions of the fixed wire feeding block 186, and the position and angle of the wire feeding nozzle 187 away from the flare are adjusted so that the welding wire 188 is centered on the flare.

S5, aligning the adjusted light spot with the required welding seam, and adjusting the swing amplitude of the welding wire according to the welding seam, wherein the swing amplitude of the welding wire shown in the figure 4 is smaller than the width of the light spot. According to the quality of welding seam, laser power, the parameters of welding wire amplitude of oscillation and wire-feeding speed can be repeatedly regulated.

Claims

1. The utility model provides a laser welding device, the laser beam with optic fibre transmission converts into two bar faculas, combines the swing of welding wire to be used for laser welding, its characterized in that: the welding device comprises a laser light path part and a welding wire swinging mechanism part which are combined, wherein the laser light path part projects laser beams to a room-type reflector through a collimating mirror for reflection, and forms double strip-shaped light spots through focusing and reflection of a parabolic focusing mirror, the formed double strip-shaped light spots are perpendicular to the elliptical long axis of the room-type reflector surface and perpendicular to the welding advancing direction, the room-type reflector of the welding device is an elliptical mirror surface, the elliptical mirror surface consists of two symmetrical elliptical half surfaces, the two symmetrical elliptical half surfaces are symmetrically distributed similar to two surfaces of a room, an angle smaller than 1 degree is formed between the two elliptical half surfaces and a plane, the welding wire swinging mechanism comprises a mounting plate, a driving motor, an upper swinging arm, a lower swinging arm and a welding wire fixing block, and is driven by the driving motor to drive the swinging arm to drive welding wires to reciprocate in the laser strip-shaped light spots, the swing range of the welding wire is smaller than the width of a laser welding spot, the upper swing arm is connected with the driving motor through a key, the lower swing arm is sleeved in the upper swing arm and is pressed tightly through a spring device, and the welding wire fixing block is connected with the lower swing arm.

2. The laser welding apparatus according to claim 1, wherein: the laser welding device is characterized in that a collimating mirror is arranged above the room-type reflecting mirror, a collimation protective mirror is arranged above the collimating mirror, light beams projected to the room-type reflecting mirror are guaranteed to be parallel light beams, and the collimating mirror and the collimation protective mirror in the laser welding device are made of quartz or K9.

3. The laser welding apparatus according to claim 2, characterized in that: welding set arranged the CCD subassembly, CCD's spectroscope is between collimating mirror and room type speculum, and the CCD subassembly still includes CCD camera, CCD transmission device, utilizes the CCD spectroscope, and the welding seam can be observed through CCD transmission device to the CCD camera, and the facula can also be observed to the CCD camera in order to adjust the CCD subassembly according to the facula position, makes the cross in the CCD camera aim at the facula center.

4. The laser welding apparatus according to claim 1, wherein: the welding device is characterized in that a room-type reflector of the welding device is arranged below a collimating mirror, the angle of the mirror surface of the room-type reflector and the angle of the central line of the collimating mirror form an angle of 45 degrees, and the central point of the room-type reflector and the central point of the collimating mirror are on the same axis.

5. The laser welding apparatus according to claim 4, characterized in that: the two symmetrical ellipse half surfaces are distributed on two sides of the ellipse long axis, or distributed on two sides of the ellipse short axis, or distributed on the oblique symmetry line of the ellipse.

6. The laser welding apparatus according to claim 1, or claim 4, or claim 5, wherein: the parabolic focusing mirror surface of the welding device and the mirror surface of the house type reflecting mirror need to be installed face to face, the normal direction of the positive center of the parabolic focusing mirror surface and the incident direction of the light path form an angle of 45 degrees, the parabolic focusing mirror surface of the welding device and the house type reflecting mirror are made of copper or aluminum materials, and the welding device is cooled in the full water path.

7. The laser welding apparatus according to claim 6, characterized in that: a protective lens base is arranged below the parabolic focusing lens, a side blowing device is arranged on the protective lens base, an air blowing port of the side blowing device is in a transverse line belt shape, the two pieces are separately arranged, and the inner piece and the outer piece are fixed by bolts.

8. The laser welding apparatus according to claim 1, characterized in that: the welding device is characterized in that a driving motor of a welding wire swinging mechanism part of the welding device is arranged above a lens mounting seat and is arranged on a fixing plate together with the lens mounting seat, the fixing plate is connected with a flange, and the center line of a motor shaft of the driving motor and the center position of a light spot are in the same plane.

9. The laser welding apparatus according to claim 1, characterized in that: the working method of the welding device is that the driving motor drives the swing arm, and the swing arm reciprocates to enable the welding wire to reciprocate left and right in the double-strip-shaped light spots for welding.