A left and right double-head laser automatic welding jig system and welding method

Abstract

The application discloses a left-right double-head laser automatic welding jig system and a welding method, relates to the technical field of laser welding, and is suitable for automatically loading two sheet metal bending pieces in a left-right balanced arrangement mode, and then performing laser welding on the left-right corner joint seams of the sheet metal bending pieces in the jig. The system comprises a jig body, an opening and closing mechanism, a seam-reducing and pressing mechanism, left-right double laser welding heads, a detection interlocking unit and a control unit. The jig body is provided with a bearing platform, a fixed reference piece and a center limiting piece. The sheet metal bending pieces are sleeved on the fixed reference piece. The center limiting piece is located between the two sheet metal bending pieces and presses the two sheet metal bending pieces outward in an elastic sliding mode. When the in-place state of the opening and closing mechanism and / or the seam-reducing and pressing mechanism and the gap value of the corner joint seam meet the preset welding conditions, the control unit triggers the left-right double laser welding heads to perform synchronous welding, and when the conditions are not met, the control unit implements ignition interlocking. Therefore, the stability of the corner joint seam and the welding quality consistency are improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and in particular to a dual-head automatic laser welding fixture system and welding method. Background Technology

[0002] In the field of sheet metal structural component manufacturing, after bending and forming, sheet metal parts usually need to have the joints between adjacent panels welded to form a closed structure or meet strength, sealing, and appearance requirements. With the widespread application of laser welding technology in sheet metal processing, its advantages such as low heat input, fast welding speed, and good weld formation have led to its extensive use in the automated welding production of thin plates and precision sheet metal parts.

[0003] However, for sheet metal parts with bent structures, especially those with symmetrical or corner-to-corner configurations requiring welding, significant technological challenges remain in actual welding processes. On one hand, bent sheet metal parts often exhibit assembly tolerances at the corners, leading to inconsistent corner seam sizes. On the other hand, influenced by factors such as sheet metal elasticity and insufficient local rigidity, the corners are more prone to warping, misalignment, or gap changes under welding heat input, thus affecting the penetration stability and weld consistency of laser welding.

[0004] Existing laser welding fixtures mostly employ single-sided or overall clamping methods, which provide some support for straight welds or the central area. However, they often fail to provide targeted clamping and support for localized areas such as the left and right corners, making it difficult to effectively control the gaps at the left and right corners during the welding process. Furthermore, existing welding systems often use a single laser head to sequentially weld the left and right corners, resulting in a longer welding cycle and uneven heating of the left and right corners at different times, further exacerbating welding deformation and fluctuations in weld quality.

[0005] Furthermore, existing technologies lack sufficient collaborative design between welding fixtures and welding processes, failing to address the typical problem of welding gaps in the left and right corners, and thus failing to develop a stable and reliable clamping support structure and a matching automatic welding method, making it difficult to meet the demands of automated production with high consistency and high yield.

[0006] In summary, the existing technology has at least the following technical problems:

[0007] Existing laser welding fixtures lack specific clamping and support structures for the left and right corner gaps of sheet metal bending parts. When welding the left and right corners, the gap stability is poor, and it is difficult to guarantee the consistency of welding quality. Furthermore, the welding efficiency and automation adaptability need to be further improved. Summary of the Invention

[0008] The purpose of this invention is to provide a dual-head laser automatic welding fixture system and welding method to solve the problems of existing laser welding fixtures lacking targeted clamping and support structures for the left and right corner gaps of sheet metal bending parts, resulting in poor gap stability during welding of the left and right corners, difficulty in ensuring consistent welding quality, and the need for further improvement in welding efficiency and automation adaptability.

[0009] The preferred technical solutions among the many technical solutions provided by this invention can produce a variety of technical effects, which are described in detail below.

[0010] To address the aforementioned technical problems, the present invention provides the following technical solution:

[0011] This invention provides a dual-head automatic laser welding fixture system suitable for automatically loading two sheet metal bent parts in a balanced left-right arrangement, and then performing laser welding on their left and right corner joints within the fixture. The system includes a fixture body, a support platform, a fixed reference component, and a central limiting component. The sheet metal bent parts are fitted onto the fixed reference component, and the central limiting component is located between the two sheet metal bent parts and elastically slides outward to press them together. It also includes an opening and closing mechanism, comprising a pulling actuator and a pushing actuator; a joint-reducing pressing mechanism for reducing the corner joints, located on the left and right sides of the support platform; and two left and right dual laser welding heads, respectively facing the left and right corners of the two sheet metal bent parts. The system includes a joint arrangement and a detection interlocking unit, comprising at least one or more of a gap detection component and a positioning detection component, wherein the gap detection component is used to obtain the gap value of the corner joint of the sheet metal bending part, and the positioning detection component is used to obtain the positioning state of the opening and closing mechanism and / or the joint reduction and pressing mechanism; and a control unit electrically connected to the opening and closing mechanism, the left and right dual laser welding heads and the detection interlocking unit, for triggering the two left and right dual laser welding heads to perform synchronous welding when the positioning state and the gap value of the corner joint on the left and right sides of the two sheet metal bending parts meet the preset welding conditions, and implementing ignition interlocking on the two left and right dual laser welding heads when the preset welding conditions are not met.

[0012] In one embodiment, the gap-reducing pressing mechanism includes an outward-moving linkage group, driven by the pulling actuator, for moving the pressing member on the outward-moving linkage group outward in a direction away from the fixed reference member to form a loading channel. During the closing pressing stage, an elastic element provides elastic force to press against the sheet metal bending piece to reduce the corner joint on the front side; and two corner pressing claws, respectively disposed on the left side of the left sheet metal bending piece and the right side of the right sheet metal bending piece, and providing inward preload through elastic elements to reduce the corner joint on the front side of the two sheet metal bending pieces. During the closed pressing phase, the corner pressing claw is pressed against the fixed reference member to reduce the corner joint seam on the side; the corner pressing claw on the left side is moved outward by the outward linkage group and expands outward in a direction away from the fixed reference member to release the pressing of the sheet metal bending part; and the release holding group, driven by the push actuator, is used to apply a push to the corner pressing claw on the right side in the open waiting state to limit the pressing of the sheet metal bending part, and release the push during the closed pressing phase so that the corner pressing claw rebounds and presses against the sheet metal bending part under the action of the elastic element.

[0013] In one embodiment, the fixed reference component is a positioning block arranged through the left and right direction, and the two positioning blocks include a first fixed block and a second floating block; the sheet metal bending piece on the left is fitted onto the first fixed block, and the sheet metal bending piece on the right is fitted onto the second floating block; the first fixed block is fixedly mounted on the bearing platform; the bottom of the second floating block is provided with a slide rail assembly along the left and right direction, which is driven and pressed against the center limiting component by the corner pressing claw and the elastic element on the right; the pressing force of the pressing component and the corner pressing claw has a component force toward the first fixed block and the second floating block, so that the two sheet metal bending pieces form a gap-reducing positioning that returns to the reference zero of the fixed reference component during the closed pressing stage.

[0014] In one embodiment, the bottom of the central limiting member is provided with a guide sliding assembly in the left-right direction. Elastic elements are provided on both the left and right sides of the central limiting member, acting elastically on the first fixed block and the second floating block respectively. When the release pressure assembly is in the open-ready state, it pushes itself and the second floating block outward with the corner pressing claw on the right side. The two sides of the central limiting member have adaptive pressing surfaces that press against the sides of the two sheet metal bending parts. The central limiting member determines the direction of movement through the guide sliding assembly and limits the maximum pressing stroke through the adaptive pressing surface, the push actuator, and the elastic elements, forming a compliant pressing that can compensate for tolerances on both sides of the two sheet metal bending parts, thereby reducing the corner joint seam on the sides of the two sheet metal bending parts.

[0015] In one embodiment, the outward movement linkage group includes a first sliding pair and a linkage sliding pair; the pressing member is mounted on the first sliding pair, and the first sliding pair drives the pressing member to slide towards or away from the front direction of the two sheet metal bending parts located at the corner joint; the left corner pressing claw is mounted on the linkage sliding pair, and the linkage sliding pair drives the corner pressing claw to slide towards or away from the left side of the corresponding sheet metal bending part; the release pressing group includes a second sliding pair, and the right corner pressing claw is mounted on the second sliding pair, and the second sliding pair drives the corner pressing claw to slide towards or away from the right side of the corresponding sheet metal bending part; elastic elements are installed on the slide rods of the first sliding pair, the linkage sliding pair, and the second sliding pair.

[0016] In one embodiment, the gap detection component is a displacement / laser ranging sensor respectively installed at the left and right corners of the two sheet metal bending parts, with the detection direction consistent with the normal of the corner joint; the control unit uses the gap value of the corner joint on both sides of the two sheet metal bending parts not being greater than a preset gap threshold as one of the preset welding conditions that allow the left and right dual laser welding heads to ignite.

[0017] In one embodiment, the synchronous welding and safety interlocking logic of the control unit includes:

[0018] When both sheet metal bending parts simultaneously meet the preset welding conditions, the two left and right dual laser welding heads are triggered to ignite synchronously and execute synchronous welding cycles; when the gap value of the corner joint of one or both sides of any sheet metal bending part does not meet the preset welding conditions, the ignition of the left and right dual laser welding heads of the corresponding sheet metal bending part is prohibited.

[0019] In one embodiment, the system further includes a welding head calibration and anti-collision unit electrically connected to the control unit and an anti-collision detection program configured within the control unit; the welding head calibration and anti-collision unit includes a calibration reference component for establishing a spatial reference for the left and right dual laser welding heads relative to the fixture body; and an anti-collision detection component for detecting abnormal proximity between the left and right dual laser welding heads or attached optical components and the fixture body or the sheet metal bending component; when the anti-collision detection program is triggered, the control unit stops the ignition action of the left and right dual laser welding heads and performs the retraction action of the left and right dual laser welding heads.

[0020] A left-right dual-head automatic laser welding method is also provided, applied to a left-right dual-head automatic laser welding fixture system, including the following steps: S1, opening for assembly: controlling the opening and closing mechanism to drive the pull actuator to drive the outward movement linkage group of the gap reduction pressing mechanism to move outward, so that the pressing component provided on the outward movement linkage group moves outward in a direction away from the first fixed block and the second floating block to form a loading channel, and drives the left corner pressing claw to move outward in a direction away from the first fixed block to release the pressing of the sheet metal bending part; and controlling the push actuator to drive the release holding group to apply a push to the corner pressing claw to release the pressing of the sheet metal bending part away from the second floating block, so that the center limiting member moves outward with the second floating block in an elastic sliding manner and maintains the open assembly gap, and the center limiting member is located between the first fixed block and the second floating block, in the open assembly state;

[0021] S2. Automatic loading: The automatic loading fixture loads the two sheet metal bending parts on the left and right sides onto the fixed reference part of the fixture body, so that the sheet metal bending part on the left side is sleeved on the first fixed block and the sheet metal bending part on the right side is sleeved on the second floating block, thus completing the initial positioning.

[0022] S3, Closed Pressing to Reduce Gap: Control the pull actuator to return to its original position, so that the outward movement linkage group resets and rebounds under the action of the elastic element, driving the pressing component to press against the sheet metal bending part in the closed pressing stage, so as to reduce the corner joint on the front; control the push actuator to return to its original position to release the push of the pressing group, so that the corner pressing claw on the right side rebounds and presses against the sheet metal bending part under the action of the elastic element, while the corner pressing claw on the left side resumes pressing against the sheet metal bending part as the outward movement linkage group resets, and under the elastic external pressing cooperation of the center limiter, the two sheet metal bending parts form a gap-reducing positioning towards the zero reference of the fixed reference part in the closed pressing stage, so as to reduce the corner joint on the side.

[0023] S4. Detection and Interlocking: The detection interlocking unit is used to obtain the positioning status of the opening and closing mechanism and / or the gap reduction and pressing mechanism, and to obtain the gap value of the corner joint on the left and right sides of the two sheet metal bending parts; the positioning status and gap value are compared with the preset welding conditions.

[0024] S5. Dual-head synchronous welding: When the preset welding conditions are met, the two left and right dual laser welding heads are triggered to perform synchronous welding on the corner joints on the left and right sides of the two sheet metal bending parts; when the preset welding conditions are not met, the two left and right dual laser welding heads are interlocked for ignition.

[0025] In one embodiment, S4 and S5 include at least one of the following control strategies: when the gap value of the joint seam on one or both sides of any sheet metal bending part is greater than the preset gap threshold and / or the positioning state of any sheet metal bending part is not satisfied, the ignition of the corresponding left and right double laser welding heads is prohibited, and the opening and closing mechanism is controlled to repeat the closing and pressing seam reduction action of S3 once and then execute S4 again; before triggering synchronous welding, the welding head calibration and anti-collision unit is called to establish the spatial reference of the left and right double laser welding heads relative to the fixture body, and when the anti-collision detection component detects abnormal proximity, the ignition is stopped and the retraction action of the left and right double laser welding heads is executed.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) The stability of the gaps in the left and right corners is significantly improved.

[0028] This technical solution sets a fixed reference component and a central limiting component on the fixture body, so that two sheet metal bending parts are automatically loaded and fitted onto the fixed reference component in a left-right balanced arrangement. The central limiting component is located between the two sheet metal bending parts and presses the sides of the two sheet metal bending parts outward in an elastic sliding manner. This forms a combination of reference constraint and elastic external pressing support for the sheet metal bending parts, so that the sheet metal bending parts have a stable relative position relationship and continuous pressing constraint before welding. This helps to suppress the fluctuation of the left and right corner joints caused by assembly tolerance, bending springback or thermal deformation, thereby improving the controllability and stability of the left and right corner gaps.

[0029] (2) The joint reduction effect of corner joints is more direct and more targeted.

[0030] This technical solution sets up gap-reducing pressing mechanisms on the left and right sides of the bearing platform, which are driven by the pulling actuator and the pushing actuator of the opening and closing mechanism to clamp and press the corner joint areas of the sheet metal bending parts. Compared with traditional fixtures that only press the workpiece as a whole, this technical solution uses gap-reducing pressing mechanisms on the left and right sides plus external pressing of the central limiting part to form targeted pressing and support for the corner gaps, making it easier for the corner joints to meet the preset welding conditions, and structurally improving the consistency of the corner welding quality of the sheet metal bending parts.

[0031] (3) Improved welding consistency and yield, reducing the probability of defective welding.

[0032] This technical solution sets up a detection interlock unit, including at least a gap detection component and / or a positioning detection component, to obtain the gap value of the corner joint and the positioning status of the opening / closing mechanism / seam reduction and pressing mechanism. The control unit only triggers the left and right dual laser welding heads to perform synchronous welding when it determines that the positioning status and gap value meet the preset welding conditions; if the conditions are not met, ignition interlock is implemented. This "detection judgment - interlock control" mechanism can avoid direct ignition welding in the case of abnormal gap or inadequate clamping at the source, thereby reducing the risk of defects such as incomplete welding, lack of fusion, burn-through, and undercut, and improving welding consistency and process traceability.

[0033] (4) Efficiency improvement and enhanced automation adaptability

[0034] This technical solution employs dual laser welding heads, one on the left and one on the right, facing the corner seams of two sheet metal bending parts respectively. When conditions are met, synchronous welding is performed on the corner seams of a single sheet metal bending part. Compared with single welding head welding on each side sequentially, synchronous welding can shorten the cycle time, reduce the impact of workpiece posture changes and gap drift caused by sequential heating of the left and right corners, and better meet the cycle time production requirements after automatic loading, thus improving the automation adaptability of the production line.

[0035] (5) Enhanced safety and equipment protection capabilities

[0036] Ignition interlocking controls laser ignition behavior by determining the dual conditions of the position and gap value. From a process control perspective, this reduces the probability of accidental ignition or defective welding, lowers the risk of abnormalities to the workpiece, fixture, and laser head, and improves the safety and stability of system operation.

[0037] In summary, this technical solution, through the coordinated cooperation of fixed reference component positioning, elastic sliding external pressing of the central limiting component, left and right side reduced gap pressing, interlocking of gap value / position status detection, and synchronous welding of left and right double heads, enables the corner joints on both sides of the sheet metal bending parts to have better stability and controllability before welding. It also realizes condition judgment and synchronous welding control during the welding process, thereby improving the consistency of welding quality, production cycle and automation adaptability. Attached Figure Description

[0038] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is an isometric structural diagram of the assembly of the sheet metal bending part, the fixture body, the gap reduction pressing mechanism and the elastic element of the present invention.

[0040] Figure 2 This is a side view structural diagram of the assembly of the sheet metal bending part, the fixture body, the gap reduction pressing mechanism and the elastic element of the present invention;

[0041] Figure 3 This is a top view schematic diagram of the assembly of the fixture body, the gap-reducing pressing mechanism, and the elastic element of the present invention;

[0042] Figure 4 This is a first isometric structural schematic diagram of the assembly of the fixture body, the gap-reducing pressing mechanism, and the elastic element of the present invention;

[0043] Figure 5 This is a second isometric structural diagram of the assembly of the fixture body, the gap-reducing pressing mechanism, and the elastic element of the present invention;

[0044] Figure 6 This is a schematic diagram of the electrical connection between the control unit, the opening and closing mechanism, the left and right dual laser welding heads, and the joint calibration and anti-collision unit of the present invention.

[0045] Figure 7 This is a schematic diagram of the process steps of the automatic laser welding method with left and right dual heads according to the present invention.

[0046] The reference numerals in the attached figures are as follows:

[0047] 1. Sheet metal bending parts; 11. Corner joints;

[0048] 2. Fixture body; 21. Bearing platform; 22. Fixing reference component; 221. Positioning block; 222. First fixing block; 223. Second floating block; 23. Center limiting component; 231. Adaptive pressing surface; 24. Slide rail assembly; 25. Guide sliding assembly;

[0049] 3. Opening and closing mechanism; 31. Pulling actuator; 32. Pushing actuator;

[0050] 4. Joint reduction pressing mechanism; 41. Outward movement linkage group; 411. Pressing component; 412. First sliding pair; 413. Linkage sliding pair; 414. Inclined top block; 415. Rolling top column; 42. Corner pressing claw; 43. Release pressing group; 431. Second sliding pair;

[0051] 5. Dual laser welding heads (left and right);

[0052] 6. Interlock detection unit; 61. Gap detection assembly; 62. Position detection assembly;

[0053] 7. Control unit;

[0054] 8. Elastic elements;

[0055] 9. Connector calibration and anti-collision unit; 91. Calibration reference component; 92. Anti-collision detection component. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0057] The specific implementation provides a dual-head laser automatic welding fixture system and welding method, suitable for automatically loading two sheet metal bending parts in a left-right balanced arrangement, and then performing laser welding on their left and right corner joints within the fixture; the system includes a fixture body, an opening and closing mechanism, a joint reduction and pressing mechanism, left and right dual laser welding heads, a detection interlocking unit, and a control unit; the fixture body is provided with a bearing platform, a fixed reference component, and a central limiting component; the sheet metal bending parts are fitted onto the fixed reference component, and the central limiting component is located between the two sheet metal bending parts and presses the two sheet metal bending parts outward in an elastic sliding manner. For bent sheet metal parts, the control unit triggers simultaneous welding of the left and right dual laser welding heads when it determines that the opening and closing mechanism and / or the gap reduction and pressing mechanism are in position and that the gap value of the corner joint meets the preset welding conditions. If the conditions are not met, ignition interlocking is implemented. This improves the stability of the corner joint and the consistency of welding quality. It effectively solves the problem that existing laser welding fixtures lack targeted clamping and support structures for the left and right corner gaps of bent sheet metal parts, resulting in poor gap stability and difficulty in ensuring consistent welding quality when welding the left and right corners. Furthermore, the welding efficiency and automation adaptability need to be further improved.

[0058] The first implementation of a dual-head laser automatic welding fixture system, for example Figures 1 to 6As shown, this fixture is suitable for automatically loading two sheet metal bent parts 1 in a balanced left-right arrangement, and then performing laser welding on their left and right corner joints 11 within a fixture. The fixture includes a fixture body 2, a support platform 21, a fixed reference component 22, and a central limiting component 23. The sheet metal bent parts 1 are fitted onto the fixed reference component 22, and the central limiting component 23 is located between the two sheet metal bent parts 1 and elastically slides outward to press the two sheet metal bent parts 1 together. It also includes an opening and closing mechanism 3, including a pulling actuator 31 and a pushing actuator 32; a joint-reducing pressing mechanism 4 for reducing the corner joints 11, located on the left and right sides of the support platform 21; and two left and right double laser welding heads 5, respectively facing the left and right corner joints of the two sheet metal bent parts 1. The system includes a joint 11 arrangement; and a detection interlocking unit 6, comprising at least one or more of a gap detection component 61 and a positioning detection component 62. The gap detection component 61 is used to obtain the gap value of the corner joint 11 of the sheet metal bending part 1, and the positioning detection component 62 is used to obtain the positioning status of the opening and closing mechanism 3 and / or the gap reduction and pressing mechanism 4; and a control unit 7, electrically connected to the opening and closing mechanism 3, the left and right double laser welding heads 5 and the detection interlocking unit 6, for triggering the two left and right double laser welding heads 5 to perform synchronous welding when the positioning status and the gap value of the corner joint 11 on the left and right sides of the two sheet metal bending parts 1 meet the preset welding conditions, and implementing ignition interlocking for the two left and right double laser welding heads 5 when the preset welding conditions are not met.

[0059] Specifically, addressing the technical problems of existing laser welding fixtures, such as the lack of targeted clamping and support structures for the left and right corner gaps of sheet metal bending parts 1, poor gap stability, difficulty in ensuring welding consistency, and insufficient efficiency and automation adaptability, the dual-head automatic laser welding fixture system of this technical solution has at least the following technical benefits: significantly improved stability of the left and right corner gaps; this technical solution sets a fixed reference part 22 and a central limiting part 23 on the fixture body 2, so that the two sheet metal bending parts 1 are automatically loaded and fitted onto the fixed reference part 22 in a left-right balanced arrangement, and the central limiting part 23 is located between the two sheet metal bending parts 1 and presses the sides of the two sheet metal bending parts 1 outward in an elastic sliding manner; thus forming a combination of reference constraint and elastic external pressing support for the sheet metal bending parts 1, so that the sheet metal bending parts 1 obtain a stable relative position relationship and continuous pressing constraint before welding, which helps to suppress the fluctuations of the left and right corner joints 11 caused by assembly tolerances, bending springback or thermal deformation, thereby improving the controllability and stability of the left and right corner gaps.

[0060] The corner joint 11 has a more direct and targeted reduction effect. This technical solution sets up a joint reduction pressing mechanism 4 on the left and right sides of the bearing platform 21, which is driven by the pull actuator 31 and push actuator 32 of the opening and closing mechanism 3 to clamp and press the corner joint 11 area on both sides of the sheet metal bending part 1. Compared with the traditional fixture that only presses the workpiece as a whole, this technical solution forms a targeted pressing and support for the corner gap through the joint reduction pressing mechanism 4 set on the left and right sides and the external pressing of the center limiting part 23, making it easier for the corner joint 11 to meet the preset welding conditions, and structurally improving the consistency of the corner welding quality of the sheet metal bending part 1.

[0061] This improves welding consistency and yield, reducing the probability of defective welds. The technical solution includes a detection interlock unit 6, comprising at least a gap detection component 61 and / or a positioning detection component 62, used to acquire the gap value of the corner joint 11 and the positioning status of the opening / closing mechanism 3 / reducing gap pressing mechanism 4. The control unit 7 only triggers the left and right dual laser welding heads 5 to perform synchronous welding when the positioning status and gap value meet preset welding conditions; otherwise, ignition interlocking is implemented. This "detection judgment-interlock control" mechanism can prevent direct ignition welding at the source when the gap is abnormal or the clamping is inadequate, thereby reducing the risk of defects such as incomplete welds, lack of fusion, burn-through, and undercut, and improving welding consistency and process traceability.

[0062] Efficiency improvement and enhanced automation adaptability: This technical solution adopts left and right dual laser welding heads 5 respectively facing the left and right corner joints 11 of two sheet metal bending parts 1, and performs synchronous welding on the corner joints 11 of a single sheet metal bending part 1 when the conditions are met; Compared with single welding head side-by-side sequential welding, synchronous welding can shorten the cycle time, reduce the influence of workpiece posture changes and gap drift caused by the left and right corners being heated one after the other, and better meet the cycle time production requirements after automatic loading, thus improving the automation adaptability of the production line.

[0063] Enhanced safety and equipment protection capabilities; the ignition interlock controls laser ignition behavior based on the determination of both the in-position state and the gap value. From a process control perspective, this reduces the probability of accidental ignition or defective welding, lowers the risk of abnormalities to workpieces, fixtures, and laser heads, and improves the safety and stability of system operation.

[0064] In summary, this technical solution, through the coordinated cooperation of fixed reference component 22 positioning + center limiting component 23 elastic sliding external pressing + left and right side reduced gap pressing + gap value / position status detection interlock + left and right double head synchronous welding, enables the corner joints 11 on the left and right sides of the sheet metal bending part 1 to have better stability and controllability before welding, and realizes condition judgment and synchronous welding control during the welding process, thereby improving the consistency of welding quality, production cycle and automation adaptability.

[0065] As one alternative implementation method:

[0066] Regarding the specific structure of the aforementioned joint-reducing pressing mechanism 4, this embodiment is, for example... Figures 1 to 5 As shown, the gap reduction pressing mechanism 4 includes an outward movement linkage group 41, which is driven by a pull actuator 31 to move the pressing member 411 provided on the outward movement linkage group 41 outward in a direction away from the fixed reference member 22 to form a loading channel. During the closing pressing stage, the elastic element 8 provides elastic force to press against the sheet metal bending member 1 to reduce the corner joint 11 on the front.

[0067] Two corner pressing claws 42 are respectively located on the left side of the left sheet metal bending part 1 and the right side of the right sheet metal bending part 1, and are provided with inward pre-tightening force by elastic element 8, so that the two sheet metal bending parts 1 press against the fixed reference part 22 during the closing pressing stage to reduce the corner joint 11 on the side; the corner pressing claw 42 located on the left side is moved outward by the outward linkage group 41 and expands outward in the direction away from the fixed reference part 22 to release the pressing of the sheet metal bending part 1.

[0068] And release the holding assembly 43, driven by the push actuator 32, to apply a push to the right corner pressing claw 42 in the open waiting state to limit the pressing of the sheet metal bending part 1, and release the push in the closed pressing stage so that the corner pressing claw 42 springs back to press the sheet metal bending part 1 under the action of the elastic element 8.

[0069] In application, the gap-reducing pressing mechanism 4, through the coordinated actions of the outward movement linkage group 41, the corner pressing claw 42, and the release pressing group 43, forms different clamping states in the loading and welding stages respectively. In the open and ready-to-install state, the pull actuator 31 drives the outward movement linkage group 41 to move outward, so that the pressing component 411 and the left corner pressing claw 42 move outward synchronously, thereby releasing the loading space on the front and left side of the sheet metal bending part 1. At the same time, the push actuator 32 drives the release pressing group 43 to push out the right corner pressing claw 42, restricting its pressing on the right sheet metal bending part 1, so that the two sheet metal bending parts 1 can be smoothly installed into the fixed reference part 22 and complete the initial positioning.

[0070] During the closing and pressing stage, the pull actuator 31 and push actuator 32 return to their original positions, the outward moving linkage group 41 resets, and under the action of the elastic element 8, elastically presses the front of the sheet metal bending part 1. The left and right corner pressing claws 42, under the action of the elastic element 8, spring back inward and press against the left and right sides of the sheet metal bending part 1, thereby forming a synergistic gap reduction effect on the front and side of the corner joint 11. Through this structure and its action sequence, the corner area obtains continuous, stable, and targeted clamping support before welding, suppressing gap fluctuations caused by assembly errors, bending springback, or thermal deformation, thereby improving the consistency of welding quality at the left and right corners and reducing the probability of welding defects.

[0071] In other embodiments, the linkage between the outward moving linkage group 41, the linkage sliding pair 413, and the corner pressing claw 42 is achieved by means of inclined top block 414, rolling top column 415, slider, etc.; the pressing surface of the corner pressing claw 42 is set with a toothed structure to adapt to sheet metal bending parts 1 with different bending angles or plate thicknesses; the elastic element 8 is selected as a spring.

[0072] Regarding the specific configuration of the aforementioned fixed reference member 22, this embodiment is as follows: Figures 1 to 5 As shown, the fixed reference component 22 is a positioning block 221 arranged through the left and right directions. The two positioning blocks 221 include a first fixed block 222 and a second floating block 223. The sheet metal bending component 1 on the left is fitted onto the first fixed block 222, and the sheet metal bending component 1 on the right is fitted onto the second floating block 223. The first fixed block 222 is fixedly mounted on the bearing platform 21. The bottom of the second floating block 223 is provided with a slide rail assembly 24 along the left and right directions, which is driven and pressed to the center limiting component 23 by the corner pressing claw 42 on the right and the elastic element 8. The pressing force of the pressing component 411 and the corner pressing claw 42 has a component force toward the first fixed block 222 and the second floating block 223, so that the two sheet metal bending components 1 form a gap reduction positioning that returns to the reference zero of the fixed reference component 22 during the closed pressing stage.

[0073] In application, the fixed reference component 22 is set up by a combination of the first fixed block 222 and the second floating block 223 to provide a stable and adaptive positioning reference for the two sheet metal bending parts 1. The first fixed block 222 is fixed to the support platform 21 and serves as the main reference for overall clamping; the second floating block 223 is slidably set on the support platform 21 in the left and right direction through the slide rail assembly 24, and is pressed against the center limiting component 23 by the corner pressing claw 42 on the right side and the elastic element 8, while pushing the center limiting component 23 to press against the first fixed block 222.

[0074] Through the aforementioned linkage sliding structure, during the closing pressing stage, the pressing force generated by the front pressing component 411 and the left and right corner pressing claws 42 all have a component force toward the first fixed block 222 and the second floating block 223, so that the two sheet metal bending parts 1 gradually return to the reference zero during the pressing process, realizing passive compensation and automatic correction of the left and right corner joints 11; this reference zeroing positioning method can effectively reduce the dependence on the loading accuracy, make the workpiece position relationship before welding more consistent, thereby improving the stability of corner welding quality.

[0075] In other embodiments, the sliding stroke of the second floating block 223 is limited by a limiting member or an adjustable stop; the first fixed block 222 and the second floating block 223 are designed as replaceable structures to adapt to sheet metal bending parts 1 of different models or sizes; the slide rail assembly 24 adopts a linear guide rail, dovetail groove or roller guide structure.

[0076] Regarding the specific configuration of the aforementioned center limiting member 23 and its linkage with the fixed reference member 22, this embodiment... Figures 1 to 5 As shown, the bottom of the central limiting member 23 is provided with a guide sliding assembly 25 in the left and right direction. The left and right sides of the central limiting member 23 are provided with elastic elements 8, which act on the first fixed block 222 and the second floating block 223 respectively with elastic force. When the release holding assembly 43 is in the open ready-to-install state, it pushes itself and the second floating block 223 to move outward with the corner pressing claw 42 on the right side. The two sides of the central limiting member 23 have adaptive pressing surfaces 231 that press against the sides of the two sheet metal bending parts 1. The central limiting member 23 determines the direction of movement through the guide sliding assembly 25, and limits the maximum pressing stroke through the adaptive pressing surface 231, the push actuator 32, and the elastic element 8, so as to form a compliant pressing that can compensate for the tolerance on the two sides of the two sheet metal bending parts 1, thereby reducing the corner joint seam 11 on the sides of the two sheet metal bending parts 1.

[0077] When applied, the central limiting member 23 is positioned between the two sheet metal bending members 1 and slides in a restricted manner in the left and right directions via the guide sliding assembly 25. At the same time, the elastic elements 8 on its left and right sides apply elastic forces to the first fixed block 222 and the second floating block 223 respectively.

[0078] In the open, ready-to-load state, the pressure holding assembly 43 pushes the right corner pressing claw 42, causing the central limiting member 23 and the second floating block 223 to move outward synchronously, thus providing sufficient central space for loading. During the closed pressing stage, the central limiting member 23, under the action of the elastic element 8, presses the two sheet metal bending parts 1 outward to both sides, forming a coordinated pressing with the left and right corner pressing claws 42, so that both sides of the sheet metal bending parts 1 are supported in a compliant manner and with tolerance compensation. Through this central external pressing structure, the relative offset of the two sheet metal bending parts 1 before and during welding can be further suppressed, improving the symmetry and stability of the left and right corner joints 11.

[0079] In other embodiments, the adaptive pressing surface 231 of the center limiting member 23 can be configured as a replaceable module; the stiffness of the elastic element 8 can be adjusted according to the plate thickness or welding process parameters.

[0080] Regarding the specific configuration of the aforementioned outward movement linkage group 41, release and holding group 43, and springback clamping structure, this implementation is as follows: Figures 1 to 5 As shown, the outward movement linkage group 41 includes a first sliding pair 412 and a linkage sliding pair 413; the pressing member 411 is installed on the first sliding pair 412, and the first sliding pair 412 drives the pressing member 411 to slide towards or away from the front direction of the two sheet metal bending parts 1 located at the corner joint 11; the left corner pressing claw 42 is installed on the linkage sliding pair 413, and the linkage sliding pair 413 drives the corner pressing claw 42 to slide towards or away from the left side of the corresponding sheet metal bending part 1.

[0081] The release pressure holding assembly 43 includes a second sliding pair 431, and the corner pressing claw 42 on the right side is mounted on the second sliding pair 431. The second sliding pair 431 drives the corner pressing claw 42 to slide toward or away from the right side of the sheet metal bending part 1. Elastic elements 8 are all mounted on the slide rods of the first sliding pair 412, the linkage sliding pair 413, and the second sliding pair 431.

[0082] In application, the first sliding pair 412, the linked sliding pair 413, and the second sliding pair 431, through their respective sliding directions and elastic rebound characteristics, achieve independent control of front pressing, left corner pressing, and right corner pressing, respectively. The pull actuator 31 drives the first sliding pair 412 and the linked sliding pair 413 to move outward or return synchronously, allowing the front pressing component 411 and the left corner pressing claw 42 to automatically switch working states during the loading and welding stages. The push actuator 32, through the second sliding pair 431, restricts or releases the right corner pressing claw 42, thus forming asymmetrical timing control of the left and right corner pressing. This separate sliding and elastic rebound structure makes the gap-reducing pressing action smoother and more reliable, further reducing the risk of workpiece displacement caused by rigid impact.

[0083] In other embodiments, each sliding pair adopts a combination structure of guide rod and slider; the elastic element 8 can adopt a multi-stage elastic combination.

[0084] Regarding the specific settings of the aforementioned gap detection component 61, as follows: Figure 6 As shown, the gap detection component 61 is a displacement / laser ranging sensor set on the left and right corners of the two sheet metal bending parts 1 respectively, and the detection direction is consistent with the normal of the corner joint 11; the control unit 7 uses the gap value of the corner joint 11 on both the left and right sides of the two sheet metal bending parts 1 not being greater than the preset gap threshold as one of the preset welding conditions that allow the left and right double laser welding heads 5 to ignite.

[0085] In application, the gap detection component 61 uses displacement or laser ranging sensors at the left and right corners to detect the corner joint 11 in real time and transmits the detection results to the control unit 7. The control unit 7 only allows the left and right dual laser welding heads 5 to ignite and weld when it detects that both left and right corner joints 11 are within the preset gap threshold range. Through the detection interlocking mechanism, welding can be effectively avoided when the gap is abnormal or the pressing is incomplete, thereby reducing the risk of defects such as incomplete welding and lack of fusion, and improving welding consistency.

[0086] In other embodiments, the gap detection component 61 can be replaced by visual inspection, structured light inspection, or inductive displacement inspection; the detection results can be used for adaptive adjustment of welding power.

[0087] Regarding the specific settings of the aforementioned arrival detection component 62, as follows: Figure 6 As shown, the positioning detection component 62 adopts a visual detection method, which identifies the positioning status of the joint reduction and pressing mechanism 4 by taking pictures and image recognition calculation; and uses positioning switches provided on the pull actuator 31 and push actuator 32 to identify the positioning status of the opening and closing mechanism 3 by the signal status of the positioning switches.

[0088] Among them, the pulling actuator 31 and the pushing actuator 32 are telescopic cylinders installed on the fixture body 2.

[0089] A second implementation example of a dual-head laser automatic welding fixture system Figures 1 to 6 As shown, the difference between this embodiment and the first embodiment is that the synchronous welding and safety interlocking logic of the control unit 7 includes: when the two sheet metal bending parts 1 simultaneously meet the preset welding conditions, the two left and right double laser welding heads 5 are triggered to ignite synchronously and execute the synchronous welding cycle; when the gap value of the single or double corner joint 11 of any sheet metal bending part 1 does not meet the preset welding conditions, the ignition of the left and right double laser welding heads 5 of the corresponding sheet metal bending part 1 is at least prohibited.

[0090] When the control unit 7 determines that the corner joints 11 of the two sheet metal bending parts 1 meet the preset welding conditions, the left and right dual laser welding heads 5 are ignited synchronously and execute synchronous welding cycles, thereby avoiding uneven heating and gap changes caused by welding the left and right corners sequentially; when the corner joints 11 of one or both sides of any sheet metal bending part 1 do not meet the conditions, the control unit 7 prohibits the corresponding welding head from igniting, so as to realize the safety interlock control of the welding process.

[0091] In other embodiments, the control unit 7 may select to perform operations in single-sided welding, reduced-power pre-welding, or rework mode based on the detection results of the gap detection component 61 and the position detection component 62.

[0092] The third implementation example of the dual-head laser automatic welding fixture system Figures 1 to 6 As shown, the difference between this embodiment and the first embodiment is that it also includes a welding head calibration and anti-collision unit 9 electrically connected to the control unit 7 and an anti-collision detection program configured in the control unit 7; the welding head calibration and anti-collision unit 9 includes a calibration reference 91 for establishing a spatial reference for the left and right dual laser welding heads 5 relative to the fixture body 2; and an anti-collision detection component 92 for detecting abnormal proximity between the left and right dual laser welding heads 5 or their attached optical components and the fixture body 2 or sheet metal bending parts; when the anti-collision detection program is triggered, the control unit 7 stops the ignition action of the left and right dual laser welding heads 5 and performs the retraction action of the left and right dual laser welding heads 5.

[0093] When applied, the welding head calibration and anti-collision unit 9 establishes the spatial relationship between the left and right dual laser welding heads 5 and the fixture body 2 through the calibration reference component 91, and monitors the relative distance between the welding head and the sheet metal bending part 1 or the fixture in real time through the anti-collision detection component 92 during the welding process.

[0094] When an abnormal approach is detected, the control unit 7 immediately stops ignition and drives the welding head to retract, thereby protecting the welding head and the fixture.

[0095] In other implementations, collision avoidance detection may employ a multi-sensor fusion approach; calibration data may be stored for use during automatic model changeover.

[0096] Based on the above embodiments of the dual-head laser automatic welding fixture system, a dual-head laser automatic welding method is provided, which is applied to the dual-head laser automatic welding fixture system, such as... Figure 7As shown, the process includes the following steps, S1 to S5, in sequence: S1, Opening for loading: The opening and closing mechanism is controlled to drive the pull actuator to move the outward linkage group of the gap reduction pressing mechanism outward, so that the pressing component provided on the outward linkage group moves outward in a direction away from the first fixed block and the second floating block to form a loading channel, and drives the corner pressing claw on the left side to move outward in a direction away from the first fixed block to release the pressing of the sheet metal bending part; and the push actuator is controlled to drive the release holding group to push the corner pressing claw away from the second floating block to release the pressing of the sheet metal bending part, so that the center limiting member moves outward with the second floating block in an elastic sliding manner and maintains the open loading gap, and the center limiting member is located between the first fixed block and the second floating block, in the open loading state;

[0097] S2. Automatic loading: The automatic loading fixture loads the two sheet metal bending parts on the left and right sides onto the fixed reference part of the fixture body, so that the sheet metal bending part on the left side is fitted onto the first fixed block and the sheet metal bending part on the right side is fitted onto the second floating block, thus completing the initial positioning.

[0098] S3, Closed Pressing to Reduce Gap: Control the pull actuator to return to its original position, so that the outward movement linkage group resets and rebounds under the action of the elastic element, driving the pressing component to press against the sheet metal bending part in the closed pressing stage, so as to reduce the corner joint on the front; control the push actuator to return to its original position to release the push of the pressing group, so that the corner pressing claw on the right side rebounds and presses against the sheet metal bending part under the action of the elastic element, while the corner pressing claw on the left side resumes pressing against the sheet metal bending part as the outward movement linkage group resets, and under the elastic external pressing cooperation of the center limiter, the two sheet metal bending parts form a gap-reducing positioning towards the zero reference of the fixed reference part in the closed pressing stage, so as to reduce the corner joint on the side.

[0099] S4. Detection and Interlocking: The detection interlocking unit is used to obtain the positioning status of the opening and closing mechanism and / or the gap reduction and pressing mechanism, and to obtain the gap value of the corner joint on the left and right sides of the two sheet metal bending parts; the positioning status and gap value are compared with the preset welding conditions.

[0100] S5. Dual-head synchronous welding: When the preset welding conditions are met, the two left and right dual laser welding heads are triggered to perform synchronous welding on the corner joints on the left and right sides of the two sheet metal bending parts; when the preset welding conditions are not met, the two left and right dual laser welding heads are interlocked for ignition.

[0101] S4 and S5 include at least one of the following control strategies: when the gap value of the corner joint of any sheet metal bending part on one or both sides is greater than the preset gap threshold and / or the positioning state of any sheet metal bending part is not satisfied, the ignition of the corresponding left and right double laser welding heads is prohibited, and the opening and closing mechanism is controlled to repeat the closing and pressing gap reduction action of S3 once and then execute S4 again; before triggering synchronous welding, the welding head calibration and anti-collision unit is called to establish the spatial reference of the left and right double laser welding heads relative to the fixture body, and when the anti-collision detection component detects abnormal proximity, the ignition is stopped and the retraction action of the left and right double laser welding heads is executed.

[0102] When applied, by integrating clamping action, gap reduction pressing action, detection interlock logic and left and right double-head synchronous welding sequence into the same welding method, the sheet metal bending parts are always in a controlled clamping and support state before and after welding.

[0103] In step S1, through the coordinated control of the pull actuator and the push actuator, the outward movement linkage group, the corner pressing claw, and the center limiting component are simultaneously put into the open and ready-to-load state, providing sufficient space for automatic loading. In step S2, the two sheet metal bending parts are fitted onto the first fixed block and the second floating block in a left-right balanced manner, achieving rapid and fault-tolerant initial positioning. In step S3, through the coordinated action of the outward movement linkage group reset, the release pressing group reset, the corner pressing claw elastic rebound, and the center limiting component elastic external pressing, the sheet metal bending parts simultaneously form a reduced-gap pressing state towards the fixed reference part in both the front and side directions, thereby stabilizing and unifying the gap conditions of the left and right corner joints before welding. In step S4, the detection interlocking unit judges the clamping position and the corner joint gap value, and only allows the welding step to proceed when the preset welding conditions are met. In step S5, the left and right dual laser welding heads are simultaneously ignited and perform welding, avoiding gap changes or deformation differences in the left and right corners due to sequential welding from the perspectives of time and heat input.

[0104] By continuously executing the above steps, the corner joint is stabilized, reduced, and kept within a controllable range before welding. At the same time, during the welding process, interlocking logic is used to avoid welding with defects. This effectively solves the problems of poor stability of left and right corner gaps, difficulty in ensuring welding consistency, and insufficient reliability of automated welding in the existing technology. It also improves the overall welding cycle time and automation adaptability while ensuring welding quality.

[0105] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A dual-head automatic laser welding fixture system, suitable for automatically loading two sheet metal bending parts in a balanced left-right arrangement, and then performing laser welding on the corner joints on both sides of the two sheet metal bending parts, characterized in that... The system includes a fixture body, an opening and closing mechanism, a gap-reducing pressing mechanism, left and right dual laser welding heads, a detection interlocking unit, and a control unit. The fixture body is provided with a bearing platform, a fixed reference component, and a central limiting component. The bearing platform is provided with a fixed reference component and a central limiting component. The fixed reference component consists of two positioning blocks arranged through the left and right directions, which are a first fixed block and a second floating block, respectively. The first fixed block is fixedly mounted on the bearing platform. The bottom of the second floating block is provided with a slide rail assembly. The sheet metal bending component on the left is fitted into the first fixed block, and the sheet metal bending component on the right is fitted into the second floating block. The central limiting member slides in a restricted manner in the left and right direction through the guide sliding assembly. The left and right sides of the central limiting member are provided with first elastic elements and act on the first fixed block and the second floating block respectively with elastic force. The central limiting member is located between two sheet metal bending parts and can elastically slide to press the two sheet metal bending parts outward. The opening and closing mechanism includes a pulling actuator and a pushing actuator; the gap-reducing pressing mechanism includes an outward moving linkage group, a left corner pressing claw, a right corner pressing claw, and a release pressing group; the outward moving linkage group includes a first sliding pair and a linkage sliding pair; the left corner pressing claw and the right corner pressing claw are respectively located on the left side of the left sheet metal bending part and the right side of the right sheet metal bending part; The pressing component is mounted on the first sliding pair, and the left corner pressing claw is mounted on the linkage sliding pair; the release pressing assembly includes a second sliding pair, and the right corner pressing claw is mounted on the second sliding pair; The first sliding joint, the linked sliding joint, and the second sliding joint are all equipped with second elastic elements on their sliding rods. The pull actuator drives the first sliding joint and the linked sliding joint to move outward or return synchronously, so that the first sliding joint moves the pressing component closer to or away from the front side of the two sheet metal bending parts, and the linked sliding joint moves the left corner pressing claw closer to or away from the left side of the corresponding sheet metal bending part. The push actuator restricts or releases the right corner pressing claw through the second sliding joint, so that the second sliding joint moves the right corner pressing claw closer to or away from the right side of the corresponding sheet metal bending part. During the closing and pressing stage, the pull actuator and push actuator return to their original positions, the outward linkage group resets, and under the action of the second elastic element, elastically presses the front side of the sheet metal bending part. The left corner pressing claw and the right corner pressing claw, under the action of the second elastic element, respectively spring back inward and press against the left side of the left sheet metal bending part and the right side of the right sheet metal bending part. The two laser welding heads are positioned facing the corner joints on the left and right sides of the two sheet metal bending parts, respectively. The interlock detection unit includes at least a gap detection component and a position detection component. The gap detection component is used to obtain the gap value of the corner joint of the sheet metal bending part, and the position detection component is used to obtain the position status of the opening and closing mechanism and / or the joint reduction and pressing mechanism. The control unit is electrically connected to the opening and closing mechanism, the left and right dual laser welding heads, and the detection interlocking unit. It is used to trigger the two left and right dual laser welding heads to perform synchronous welding when the positioning state and the gap value of the corner joint on the left and right sides of the two sheet metal bending parts meet the preset welding conditions, and to implement ignition interlocking on the two left and right dual laser welding heads when the preset welding conditions are not met.

2. The dual-head automatic laser welding fixture system according to claim 1, characterized in that, When the release holding assembly is in the open ready-to-install state, the central limiting member pushes itself and the second floating block outward along with the right corner pressing claw; the two sides of the central limiting member have adaptive pressing surfaces that press against the sides of the two sheet metal bending parts; the central limiting member determines the direction of movement through the guide sliding assembly, and limits the maximum pressing stroke through the adaptive pressing surface, the push actuator, and the first elastic element, so as to form a compliant pressing that can compensate for tolerances on the sides of the two sheet metal bending parts, thereby reducing the corner joint of the two sheet metal bending parts.

3. The dual-head automatic laser welding fixture system according to claim 2, characterized in that, The gap detection component consists of displacement / laser ranging sensors installed on the corner joints on the left and right sides of the two sheet metal bending parts, with the detection direction aligned with the normal of the corner joints. The control unit uses the gap value of the corner joints on the left and right sides of the two sheet metal bending parts not exceeding a preset gap threshold as one of the preset welding conditions that allow the left and right dual laser welding heads to ignite.

4. The dual-head automatic laser welding fixture system according to claim 3, characterized in that, The system also includes a welding head calibration and anti-collision unit electrically connected to the control unit, and an anti-collision detection program configured within the control unit; the welding head calibration and anti-collision unit includes a calibration reference component for establishing a spatial reference for the left and right dual laser welding heads relative to the fixture body; and an anti-collision detection component for detecting abnormal proximity between the left and right dual laser welding heads or attached optical components and the fixture body or sheet metal bending parts; when the anti-collision detection program is triggered, the control unit stops the ignition action of the left and right dual laser welding heads and performs the retraction action of the left and right dual laser welding heads.

5. A method for automatic laser welding with dual heads, applied to the automatic laser welding fixture system with dual heads as described in claim 4, characterized in that, The method includes the following steps: S1. Open for loading: Control the opening and closing mechanism to drive the pull actuator to move the outward linkage group of the gap reduction pressing mechanism outward, so that the pressing component on the outward linkage group moves outward in a direction away from the first fixed block and the second floating block to form a loading channel, and drives the left corner pressing claw to move outward away from the first fixed block to release the pressing on the sheet metal bending part on the left; and control the push actuator to drive the release pressing group to push the right corner pressing claw away from the second floating block to release the pressing on the sheet metal bending part on the right, so that the center limiting member moves outward with the second floating block in an elastic sliding manner and maintains the open loading gap, and the center limiting member is located between the first fixed block and the second floating block, in the open loading state; S2. Automatic loading: The two sheet metal bending parts are loaded onto the fixed reference part of the fixture body by the automatic loading fixture, so that the sheet metal bending part on the left is fitted onto the first fixed block and the sheet metal bending part on the right is fitted onto the second floating block, thus completing the initial positioning. S3, Closed Pressing to Reduce Gap: Control the pull actuator to return to its original position, so that the outward movement linkage group resets and rebounds under the action of the second elastic element, driving the pressing component to press against the sheet metal bending part during the closed pressing stage, so as to reduce the corner joint on the front; control the push actuator to return to its original position to release the push of the pressing group, so that the corner pressing claw on the right side rebounds and presses against the sheet metal bending part on the right side under the action of the second elastic element, while the corner pressing claw on the left side resumes pressing against the sheet metal bending part on the left side as the outward movement linkage group resets, and under the elastic external pressing cooperation of the center limiter, the two sheet metal bending parts form a gap-reducing positioning towards the zero reference of the fixed reference part during the closed pressing stage, so as to reduce the corner joint; S4. Detection and Interlocking: The positioning status of the opening and closing mechanism and / or the gap reduction and pressing mechanism is obtained through the detection and interlocking unit, and the gap value of the corner joint on the left and right sides of the two sheet metal bending parts is obtained; the positioning status and gap value are compared with the preset welding conditions. S5. Dual-head synchronous welding: When the preset welding conditions are met, the two left and right dual laser welding heads are triggered to perform synchronous welding on the corner joints on the left and right sides of the two sheet metal bending parts; when the preset welding conditions are not met, the two left and right dual laser welding heads are interlocked for ignition.

6. The automatic laser welding method with left and right dual heads according to claim 5, characterized in that, Before triggering dual-head synchronous welding, the welding head calibration and anti-collision unit is called to establish a spatial reference between the left and right dual laser welding heads and the fixture body. When the anti-collision detection component detects abnormal proximity, ignition is stopped and the retraction action of the left and right dual laser welding heads is executed.

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