A welding device for sheet members and a working method thereof

Abstract

The application discloses a welding device for plate members and a working method thereof, which comprises a single-shaft machine tool and a welding device arranged on the side of the single-shaft machine tool. The plate to be welded has a first surface, a second surface and a third surface. The first surface is the top surface of the bent plate member. The second surface is formed by bending the length direction side of the first surface, and constitutes a first bent surface. The third surface is formed by bending the width direction side of the first surface, and constitutes a second bent surface. The butt edges of the first bent surface and the second bent surface constitute four weld seams to be welded. The four weld seams to be welded are welded in sequence in the clockwise or counterclockwise direction. The top ends of the last two weld seams to be welded, the device solves the problems of unstable fixing of the box body and missing of the left and right side notch detection reference in the prior art, and achieves the effects of accurately identifying and fixing the workpiece before welding, and providing a unified reference for synchronous detection and subsequent correction of the double-sided notches.

Description

Technical Field

[0001] This invention relates to the field of plate welding technology, and more specifically, to a welding apparatus for plate components and a method of operation thereof. Background Technology

[0002] Currently, box-shaped components, formed by bending and welding sheet metal, are widely used in sheet metal processing and metal component manufacturing. These components are typically made by repeatedly bending flat sheet metal into a specific shape, followed by welding the bent and joined edges to complete the overall assembly. Common sheet metal component welding equipment on the market usually includes fixtures for fixing the workpiece and welding equipment for performing the welding. The bent sheet metal is fixed to the fixture, and then the welding equipment performs welding along the butt joint.

[0003] In actual production, especially for aluminum alloy sheet components, due to precision deviations in the bending process and the springback of the aluminum alloy sheet after bending, the butt joint surfaces of the bent surfaces often fail to fit ideally, forming gaps at the top of the weld. Furthermore, for components requiring multiple bends, the thermal stress generated during the initial welding process accumulates within the component and is gradually released, concentrating at the last two free edges to be welded, further widening the gap. If this gap is not detected and addressed before welding and proceeds directly to the laser welding process, the gap will exceed the allowable range of laser welding, making it difficult for the welding beam to effectively fuse the gap simultaneously, resulting in defects such as incomplete welds or missed welds. In addition, the welding heat input exacerbates local deformation, making it difficult for the gap area to close after welding, ultimately leading to substandard product dimensions. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a welding device for plate components and its working method.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A welding apparatus for sheet metal components includes a single-axis machine tool and welding equipment disposed beside the single-axis machine tool. The sheet metal to be welded has a first side, a second side, and a third side. The first side is the top surface of the bent sheet metal component. The second side is formed by bending one side of the first side along its length, constituting a first bent surface. The third side is formed by bending one side of the first side along its width, constituting a second bent surface. The butt joint edges of the first and second bent surfaces form four weld seams. The four weld seams are welded sequentially in a clockwise or counterclockwise direction. The tops of the last two weld seams form notches at the intersection of the first bent surface and the second bent surfaces on their left and right sides. The receiving equipment is equipped with a camera for detecting the notch; the single-axis machine tool is also equipped with a preliminary positioning reference mechanism and a clamping inner support correction mechanism; the preliminary positioning reference mechanism includes a platform and a positioning rotating part; the platform is fixed on the single-axis machine tool and is used to support the plate to be welded; there are two positioning rotating parts, which are respectively arranged on the left and right sides of the platform, for diagonally clamping and fixing the plate to be welded, and providing a positioning reference for the detection of the camera; the clamping inner support correction mechanism has two sets, left and right, which are respectively used to lift the first bending surface and the second bending surface of the corresponding weld area from the inside, and to press down and correct the lifted part from the outside to reduce the corresponding notch.

[0006] By adopting the above technical solution, the problems of unstable box fixing and lack of detection benchmarks for the left and right side gaps in the existing technology are solved, achieving the effect of accurately identifying and fixing the workpiece before welding, and providing a unified benchmark for the synchronous detection and subsequent correction of the double-sided gaps.

[0007] The invention is further configured such that: both positioning and rotating parts are L-shaped pressure arms, and the two L-shaped pressure arms are respectively disposed on the left and right sides of the platform; the pressing end of the left L-shaped pressure arm abuts against the upper left corner of the plate component to be welded, and the pressing end of the right L-shaped pressure arm abuts against the lower right corner of the plate component to be welded, and the two L-shaped pressure arms form diagonal pressing in the diagonal direction of the plate component to be welded.

[0008] The present invention is further configured such that: the preliminary positioning reference mechanism also includes a driving unit; the driving unit is provided on the platform and there are two of them, and the output ends of the two driving units are respectively connected to the positioning rotating unit, and when the driving unit is started, it can drive the positioning rotating unit to move upward toward the plate to be welded.

[0009] The present invention is further configured such that: the pressing internal support correction mechanism has two sets, the two sets of pressing internal support correction mechanisms are respectively set corresponding to the notches on the left and right sides of the plate to be welded, and are both located below the platform and the plate to be welded pressed onto the platform; each set of pressing internal support correction mechanism includes a first mounting part, a vertical drive member and a first mating part; the first mounting part is located below the platform; the vertical drive member is located at the top of the first mounting part; the first mating part is located at the output end of the vertical drive member, and the first mating part faces the inner side of the first bending surface and the second bending surface on the corresponding side.

[0010] The present invention is further configured such that: the first mating part includes a first abutting surface and a second abutting surface; both the first abutting surface and the second abutting surface are cuboid structures, and the end face of the cuboid structure and the contact surface with the inner side of the plate to be welded are chamfered structures, and there is a clearance groove between the first abutting surface and the second abutting surface, the clearance groove being away from the position of the weld to be welded.

[0011] The present invention is further configured such that: the first abutting surface and the second abutting surface are higher than the top plane of the first mating part; the first abutting surface is used to abut the inner side of the first bending surface, and the second abutting surface is used to abut the inner side of the second bending surface.

[0012] The present invention is further configured such that: the clamping internal support correction mechanism includes four sets of horizontal moving parts, four sets of downward driving members, four sets of downward pressing parts, and four sets of protrusions. Among the four sets of horizontal moving parts, two sets correspond to the left notch and are respectively located on both sides of the notch, and the other two sets correspond to the right notch and are respectively located on both sides of the notch. Each set of horizontal moving parts is slidably disposed on the platform and close to one side of the positioning rotating part. Each set of downward driving members is disposed on the top of the corresponding horizontal moving part. Each set of downward pressing parts is slidably disposed on the outside of the output rod of the corresponding downward driving member, and the downward pressing part is an L-shaped structure. The L-shaped structure has two first contact surfaces and second contact surfaces that contact the plate to be welded. The first contact surface is used to contact the side of the corresponding side bending surface, and the second contact surface is used to contact the outer side of the corresponding side bending surface. Each set of protrusions is disposed on the corresponding second contact surface, and the protrusions are triangular protrusion structures, and the protrusions are close to the side of the weld to be welded.

[0013] The invention is further configured such that each set of pressing parts also includes a horizontal mounting frame and a horizontal slide rail; the horizontal mounting frame is mounted on the top of the shelf and has a pair; the horizontal slide rail is slidably mounted on the horizontal mounting frame, and the top of the horizontal slide rail is connected to the horizontal moving part.

[0014] The present invention is further configured such that: each pressing part further includes a buffer unit; the buffer unit is disposed on the pressing part, and the buffer unit includes a limiting rod, a fixing plate and a buffer portion; there are multiple limiting rods respectively disposed on the top of the pressing drive member, and the limiting rods and the pressing part are clearance-fitted; the fixing plate is disposed on the outside of the multiple limiting rods, and the fixing plate is located below the pressing part; there are multiple buffer portions respectively sleeved on the outside of the limiting rods, and both ends of the multiple buffer portions abut against the fixing plate and the bottom of the pressing part respectively.

[0015] By adopting the above technical solution, when the weld cools and shrinks, the elastic potential energy stored in the buffer section pushes the pressing section downward to fill the shrinkage gap. This keeps the contact pressure of the pressing section basically constant, allowing the weld to solidify and cool under relatively low rigid restraint, reducing residual stress and ensuring the regularity of the box body after welding.

[0016] A welding method, using a welding apparatus for plate components as described above, includes the following steps: S1. Place the plate component to be welded on the platform, and activate the two drive units of the preliminary positioning reference mechanism to drive the two L-shaped positioning rotating parts on the left and right to rotate upwards on the plate, so that the clamping ends of the two L-shaped pressure arms abut against the upper corner of one side of the plate and the lower corner of the other side, respectively, to complete the macro-fixation of the plate by diagonal clamping and establish the positioning reference. With the plate fixed, the camera on the welding equipment takes pictures of the notch located at the intersection of the first bending surface and the second bending surface to obtain the size and shape information of the notch, and to determine whether there is a height difference and whether it needs to be corrected. S2. Based on the detection results of S1, when a height difference and a gap are determined to exist, the internal support correction mechanism is activated. First, the vertical drive component pushes the first mating part upward, extending from the bottom of the plate into the inner side of the box, so that the first and second abutment surfaces protruding on the first mating part abut against the inner sides of the corresponding first and second bending surfaces, forming a support reference. The clearance groove between the two abutment surfaces is aligned with the weld root to prevent the internal support force from acting directly on the weld root. Subsequently, based on the height difference detected by S, it is determined whether the first bending surface or the second bending surface is too high. The four sets of horizontal moving parts respectively drive the corresponding downward drive component, downward part, and protrusion to move as a whole to the correction position on both sides of the gap. For each gap, the downward drive component on the higher side pushes the L-shaped downward part. Moving downwards, its first contact surface contacts the side of the high-side bending surface, and the second contact surface presses against the outer surface of the high-side bending surface, performing vertical downward pressure correction on the high-side bending surface; at the same time, the triangular protrusion on the second contact surface embeds into the weld area next to the notch during the downward pressure process, squeezing the high-side bending surface from the outside inwards; the downward pressure part located on the other side of the notch contacts and cooperates with the high-side bending surface, forming opposing cooperation from both sides of the notch, causing the base materials on both sides of the notch to move towards each other, and the notch to converge inwards and shrink; during the vertical downward pressure process, the buffer unit located between the downward pressure drive and the downward pressure part works, the downward pressure part slides along the limit rod that is fitted with it, compressing the buffer part sleeved on the outside of the limit rod, converting the rigid downward pressure into an elastic correction force, which is flexibly applied to the high-side bending surface; S3. After S2 has been corrected and the lower pressure part is kept elastically pressed, the welding equipment performs laser welding along the weld seam to be welded. During the welding process, when the high side bending surface undergoes a small displacement due to thermal expansion and contraction caused by the welding heat, the compressed buffer part absorbs or compensates for the displacement through its own passive expansion and contraction, so that the pressure of the lower pressure part on the high side bending surface remains basically constant, and the weld seam completes solidification and cooling under a relatively rigid constraint.

[0017] In summary, this application includes at least one of the following beneficial technical effects: By setting up a preliminary positioning reference mechanism, the problems of unstable box fixing and lack of detection reference for the left and right side gaps in the existing technology are solved. This achieves the effect of accurately identifying and fixing the workpiece before welding and providing a unified reference for the synchronous detection and subsequent correction of the gaps on both sides.

[0018] By setting up a clamping and internal support correction mechanism, during external correction, two sets of downward driving components on both sides of each notch operate independently. The downward driving component drives the L-shaped downward pressing part to move downward, with its first contact surface contacting the side of the corresponding side bending surface, providing horizontal limitation; the second contact surface presses against the outer surface of the corresponding side bending surface, performing a vertical downward pressing action. During the movement of the horizontal moving part, the triangular protrusion on the second contact surface gradually abuts against the weld area next to the notch, squeezing the corresponding side bending surface from the outside inward and approaching the notch. After determining the higher side based on the detected height difference, the downward driving component corresponding to the higher side actively applies force, and the downward pressing part on the other side contacts and cooperates with the bending surface of the higher side, forming a counter-cooperative relationship from both sides of the notch, causing the base materials on both sides of the notch to move towards each other, and the notch to passively converge inward, thereby cooperating with the first mating part to effectively reduce the height difference and shrink the notch.

[0019] By incorporating a buffer unit, when the downward-pressing drive unit drives the lowering part to descend and conform to the second bending surface, the lowering part compresses the buffer part sleeved on the outside of the limiting rod. This compression process converts rigid downward pressure into elastic corrective force, which is flexibly applied to the higher side bending surface. During subsequent laser welding, when the higher side bending surface undergoes a slight upward displacement due to thermal expansion, this displacement pushes the lowering part to further compress the buffer part, which is absorbed without generating rigid resistance. When the weld cools and contracts, the elastic potential energy stored in the buffer part pushes the lowering part downward to fill the contraction gap. This keeps the contact pressure of the lowering part essentially constant, allowing the weld to solidify and cool under relatively low rigid restraint, reducing residual stress and ensuring a neat post-weld housing. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of a welding device for sheet metal components according to the present invention. Figure 2 This is a three-dimensional structural diagram of a welding apparatus for sheet metal components according to the present invention, showing the sheet metal to be welded in a placed state. Figure 3 This is a three-dimensional structural diagram of a preliminary positioning reference mechanism for a welding device for sheet metal components according to the present invention; Figure 4 This is a top view of the first and second bending surfaces of the plate to be welded according to the present invention. Figure 5 This is a partial three-dimensional structural view of the weld seam of the plate to be welded according to the present invention; Figure 6 This is a three-dimensional structural diagram of the compressive internal support correction mechanism of the present invention; Figure 7 for Figure 6 Enlarged structural diagram at point A in the middle; Figure 8This is a front cross-sectional view of the first mating part of the present invention in a state where it is raised and in contact with the inner side of the plate to be welded. Figure 9 A perspective view of the horizontal moving part of the present invention driving the downward pressing drive and the downward pressing part in a moving state; Figure 10 for Figure 9 Enlarged structural diagram at point B; Figure 11 This is a top perspective view of the first contact surface and the protrusion of the pressing part of the present invention. Figure 12 This is a frontal cross-sectional view of the pressing part and the first mating part of the present invention in the state of pressing the plates to be welded together with the inner and outer sides respectively.

[0021] Explanation of reference numerals in the attached drawings: 1. Single-axis machine tool; 2. Welding equipment; 3. Preliminary positioning reference mechanism; 31. Table; 32. Positioning rotating part; 33. Drive part; 4. Pressing inner support correction mechanism; 41. First mounting part; 42. Vertical drive component; 43. First mating part; 431. First abutting surface; 432. Second abutting surface; 44. Horizontal moving part; 45. Downward driving component; 46. Downward pressing part; 47. Protrusion; 48. Horizontal mounting frame; 49. Horizontal slide rail; 401. Buffer unit; 4011. Limiting rod; 4012. Fixing plate; 4013. Buffer part. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0024] Please see Figures 1-12 The present invention provides the following technical solutions: Example 1, see Figures 4-5 The state change process involves bending aluminum alloy sheets into shape and then laser welding to complete the overall assembly. In the welding process, the box is first placed on the platform 31 and fixed by the preliminary positioning mechanism, and then the welding equipment 2 welds the vertical seams on the left and right sides.

[0025] However, after completing the first few welds, a gap appears at the top bend joint of the last two vertical welds. This gap is mainly caused by two factors: First, the previous bending process itself has precision deviations; the aluminum alloy sheet springs back after bending, causing the joint surfaces of the first and second bends to not fit perfectly, leaving a gap at the bend intersection. Second, the thermal stress generated during the earlier welding process gradually accumulates and releases within the enclosure. Since the final weld area is located on the free edge of the enclosure, the stress concentrates here, further widening the already small gap and forming a noticeable gap.

[0026] This gap is often unnoticed by operators before welding and is not addressed, allowing the workpiece to proceed directly to the laser welding process. Because the gap exceeds the allowable range of laser welding, the welding beam cannot effectively fuse the gap simultaneously, leading to defects such as incomplete welds and missed welds. Furthermore, the welding heat input further exacerbates local deformation, making it difficult for the gap to close after welding. Ultimately, the final product dimensions are substandard, and both weld strength and appearance are unacceptable.

[0027] To solve the above-mentioned technical problems, this embodiment provides a welding device for sheet metal components, including a single-axis machine tool 1 and a welding device 2 disposed beside the single-axis machine tool 1. The sheet metal to be welded has a first surface, a second surface, and a third surface. The first surface is the top surface of the bent sheet metal component. The second surface is formed by bending one side of the first surface along its length, constituting a first bent surface. The third surface is formed by bending one side of the first surface along its width, constituting a second bent surface. The mating edges of the first and second bent surfaces form four weld seams. The four weld seams are welded sequentially in a clockwise or counterclockwise direction. The tops of the last two weld seams form notches at the intersection of the first bent surface and the second bent surfaces on their left and right sides. The receiving device 2 is equipped with a camera for detecting the notch; the single-axis machine tool 1 is also equipped with a preliminary positioning reference mechanism 3 and a clamping inner support correction mechanism 4; the preliminary positioning reference mechanism 3 includes a table 31 and a positioning rotation part 32; the table 31 is fixed on the single-axis machine tool 1 and is used to support the plate to be welded; there are two positioning rotation parts 32, which are respectively arranged on the left and right sides of the table 31, for diagonally clamping and fixing the plate to be welded, and providing a positioning reference for the detection of the camera; the clamping inner support correction mechanism 4 has two sets, left and right, which are respectively used to lift the first bending surface and the second bending surface of the corresponding side of the weld area to be welded from the inside, and to press down and correct the lifted part from the outside to reduce the corresponding notch.

[0028] During operation, the platform 31 in the initial positioning reference mechanism 3 supports the plate to be welded. Two positioning rotating parts 32 diagonally press the plate from the left and right sides respectively, achieving basic fixation and establishing a stable positioning reference. Subsequently, the camera on the welding equipment 2 takes pictures of the two notches to obtain their respective dimensions and shapes. Based on the test results, the left and right sets of pressing and supporting correction mechanisms 4 are activated: they lift the first and second bending surfaces on the corresponding sides from the inside of the plate to form a support reference; simultaneously, they press down and correct the area from the outside, reducing the corresponding notches and providing an accurate assembly state for subsequent laser welding. This embodiment solves the problem of the notches on the left and right sides of the box not being detected and corrected simultaneously, ensuring the accuracy of subsequent welding.

[0029] See Figure 2 and Figure 3 Both positioning and rotating parts 32 are L-shaped pressure arms, which are respectively located on the left and right sides of the platform 31. The pressing end of the left L-shaped pressure arm abuts against the upper left corner of the plate component to be welded, and the pressing end of the right L-shaped pressure arm abuts against the lower right corner of the plate component to be welded. The two L-shaped pressure arms form diagonal pressing in the diagonal direction of the plate component to be welded.

[0030] In this embodiment, two L-shaped pressure arms apply force to the plate from the left and right sides of the platform 31, with one pressing end against the upper corner of one side of the plate and the other against the lower corner of the other side. This diagonal arrangement forms a cross-pressing action, restricting the overall displacement and rotation of the plate from two directions, ensuring the stability of the plate position during subsequent internal support and external pressing.

[0031] See Figure 3 The preliminary positioning reference mechanism 3 also includes a drive unit 33; the drive unit 33 is provided on the platform 31 and there are two of them, and the output ends of the two drive units 33 are respectively connected to the positioning rotation unit 32. When the drive unit 33 is started, it can drive the positioning rotation unit 32 to move upward toward the plate to be welded.

[0032] In this embodiment, the drive unit 33 may be a rotary cylinder or a servo motor. In this embodiment, in order to improve the accuracy of the positioning rotary unit 32, the drive unit 33 is preferably a servo motor.

[0033] In Example 2, after detecting the gap with a camera and deciding to correct it, it is necessary to further analyze the reasons why the gap is difficult to close.

[0034] The enclosure panels are made of aluminum alloy. The first surface is the top surface of the bent panel component. The second surface is formed by bending one side of the first surface along its length, creating the first bent surface. The third surface is formed by bending the second surface away from the first surface, creating the second bent surface. In the bending process, the first and second bent surfaces are formed sequentially. Due to the springback phenomenon of aluminum alloy panels after bending, and the inconsistent springback amounts of the two bent surfaces, coupled with the greater influence of the cumulative error of the previous bend on the end face position of the later bent surface, a height difference will appear between the mating end faces of the first and second bent surfaces in actual production. That is, the end face of one bent surface is higher than the end face of the other bent surface, forming a gap that is difficult to close naturally.

[0035] Due to the combined effects of bending process deviations, springback, and spot welding stress, a height difference exists between the mating surfaces of the first and second bending surfaces, resulting in a gap between them. In this embodiment, the gap is the opening formed at the intersection of the first and second bending surfaces. Due to the springback and cumulative error after bending the aluminum alloy sheet, this gap is usually elliptical or teardrop-shaped, meaning that the two sides of the gap have an arc transition, with the larger opening facing outwards from the intersection of the bends, and the smaller opening extending towards the root of the weld. During laser welding, the welding beam cannot effectively fuse the base material on both sides of the gap simultaneously, leading to a weak weld. Furthermore, since the gap is formed by the first and second bending surfaces, if downward pressure is applied only from the higher bending surface, the other bending surface lacks the necessary compression, making it difficult for the base material on both sides of the gap to effectively move towards each other.

[0036] See Figure 6 The clamping internal support correction mechanism 4 has two sets, which are respectively located at the notch positions on the left and right sides of the plate to be welded, and are both located below the platform 31 and the plate to be welded pressed onto the platform 31. Each set of clamping internal support correction mechanism 4 includes a first mounting part 41, a vertical drive member 42 and a first mating part 43. The first mounting part 41 is located below the platform 31. The vertical drive member 42 is located at the top of the first mounting part 41. The first mating part 43 is located at the output end of the vertical drive member 42, and the first mating part 43 faces the inner side of the first bending surface and the second bending surface on the corresponding side.

[0037] In this embodiment, the vertical drive component 42 can be an electric push rod or a hydraulic cylinder. In this embodiment, the vertical drive component 42 is preferably an electric push rod. After the housing is fixed by the positioning and rotating part 32, each vertical drive component 42 pushes the first mating part 43 upward, so that the first mating part 43 extends from the bottom of the housing plate into the inner side of the housing and approaches the inner wall of the first bending surface and the second bending surface until the first abutting surface 431 and the second abutting surface 432 protruding on the first mating part 43 contact the inner side of the first bending surface and the second bending surface, respectively. At this time, the first mating part 43 provides a support reference for the first bending surface and the second bending surface from the inside, and its clearance groove is directly opposite the weld root position to avoid the internal support force acting directly on the weld root. The first mating part 43 and the positioning and rotating part 32 on the outside together constrain the plate to prevent overall deformation under the internal support force and subsequent external downward pressure.

[0038] See Figure 7 The first mating part 43 includes a first abutting surface 431 and abutting surface 432; both the first abutting surface 431 and the second abutting surface 432 are cuboid structures, and the end face of the cuboid structure and the contact surface with the inner side of the plate to be welded are chamfered. Furthermore, there is a clearance groove between the first abutting surface 431 and the second abutting surface 432, which is far away from the position of the weld to be welded.

[0039] The chamfered ends of the first contact surface 431 and the second contact surface 432 are designed to prevent scratching the contact surfaces of the plates and to ensure uniform stress distribution. Furthermore, the clearance groove is positioned directly opposite the weld root, leaving space for the edges on the back of the weld. This ensures that the internal support force acts only on the planar area of ​​the bending surface and does not directly contact the weld root, causing root deformation or hindering external correction. Additionally, the end faces of the first contact surface 431 and the second contact surface 432 are chamfered to accommodate the inner bending angles of the first and second bending surfaces.

[0040] See Figure 7 The first abutting surface 431 and the second abutting surface 432 are higher than the top plane of the first mating part 43; the first abutting surface 431 is used to abut the inner side of the first bending surface, and the second abutting surface 432 is used to abut the inner side of the second bending surface.

[0041] The first contact surface 431 and the second contact surface 432 protrude from the top plane of the first mating part 43. Thus, when the inner support rises, only these two protruding surfaces contact the inner sides of the first and second bending surfaces, forming localized and targeted support. This structure concentrates the supporting force on the bending surface area that needs correction, avoiding unnecessary interference to other parts.

[0042] See Figure 8 , Figure 9 and Figure 11The internal support correction mechanism 4 also includes four sets of horizontal moving parts 44, four sets of downward driving members 45, four sets of downward pressing parts 46, and four sets of protrusions 47. Of the four sets of horizontal moving parts 44, two sets correspond to the left notch and are respectively located on both sides of the notch, and the other two sets correspond to the right notch and are respectively located on both sides of the notch. Each set of horizontal moving parts 44 is slidably mounted on the platform 31 and close to one side of the positioning rotating part 32. Each set of downward driving members 45 is located on the top of the corresponding horizontal moving part 44. Each set of downward pressing parts 46... The pressing part 46 is slidably disposed on the outside of the output rod of the corresponding pressing drive member 45, and the pressing part 46 is an L-shaped structure. The L-shaped structure has two first contact surfaces and second contact surfaces that contact the plate to be welded. The first contact surface is used to contact the side of the corresponding side bending surface, and the second contact surface is used to contact the outer side of the corresponding side bending surface. Each set of protrusions 47 is disposed on the corresponding second contact surface, and the protrusions 47 are triangular protrusion structures, and the protrusions 47 are close to the side of the weld to be welded.

[0043] In this embodiment, the protrusion 47 is preferably made of copper alloy, which utilizes its excellent thermal conductivity to dissipate welding heat in a timely manner, preventing the protrusion from overheating and deforming or sticking to the aluminum alloy workpiece. Figure 11 As shown, the protrusion 47 is a wedge-shaped protrusion with a front guide ramp arranged along the horizontal movement direction, which faces the notch side. During external correction, the pressing drive 45 drives the L-shaped pressing part 46 downward, with its first contact surface contacting the side surface of the corresponding side bend and its second contact surface contacting the outer side surface of the corresponding side bend. Subsequently, the horizontal moving part 44 drives the pressing part 46 and the protrusion 47 to move closer to the notch. During the movement, the front guide ramp of the protrusion 47 first contacts the weld area next to the notch; as the horizontal moving part 44 continues to move towards the notch, the front guide ramp slides relative to the contact surface, converting the horizontal movement into an inward pressing force on the corresponding side bend, causing a slight elastic deformation or displacement of the corresponding side bend towards the center of the notch. Since two sets of downward pressing and pushing components are provided on each side of each notch, the two sets of protrusions 47 simultaneously press inward from both sides of the notch, the base materials on both sides of the notch move closer to each other, and the notch gradually converges and shrinks, thereby cooperating with the first mating part 43, effectively reducing the height difference and shrinking the notch.

[0044] In this embodiment, the protrusion 47 is designed as a protrusion rather than a flat contact for the following reasons: First, the base materials on both sides of the notch require a large force to move towards each other. The contact area between the protrusion 47 and the area beside the notch is small, so under the same total thrust, the force is concentrated on a local area beside the notch, which can produce effective opposite displacement of the base materials on both sides of the notch with a small horizontal movement. If a flat contact is used, the contact area is large and the force is dispersed, requiring a significantly larger total thrust to achieve the same effect, which can easily cause overall deformation of other parts of the housing. Second, the front guide slope of the protrusion 47 makes the contact process gradual. As the horizontal moving part 44 moves, the front guide slope gradually embeds into the area beside the notch, avoiding rigid impact and local pressure damage, and making the force on both sides of the notch uniform. Third, the protrusion 47 is close to the side of the weld but does not cover the center of the weld, so it does not block the laser welding beam and ensures that subsequent laser welding can proceed normally.

[0045] See Figure 9 Each set of pressing parts 46 also includes a horizontal mounting bracket 48 and a horizontal slide rail 49; the horizontal mounting bracket 48 is located on the top of the shelf 31 and has a pair; the horizontal slide rail 49 is slidably mounted on the horizontal mounting bracket 48, and the top of the horizontal slide rail 49 is connected to the horizontal moving part 44.

[0046] In this embodiment, a hydraulic cylinder is provided on the horizontal mounting bracket 48 for driving the horizontal slide rail 49 to move. When the hydraulic cylinder is activated, it pushes the horizontal slide rail 49 to move along the horizontal mounting bracket 48, so that the pressing part 46 accurately reaches the correction position above the corresponding side bending surface.

[0047] In Example 3, when the pressing part 46 corrects the excessively high bending surface, although it can reduce the height difference and shrink the gap, if the pressing part 46 adopts a rigid structure to directly press it, new problems will arise.

[0048] Aluminum alloys have a high coefficient of thermal expansion. During laser welding, the weld area undergoes a rapid heating and cooling cycle. When the weld is heated, the material expands and its volume increases; when the weld cools, the material contracts and its volume decreases.

[0049] If the lower pressure part 46 remains rigidly pressed after correction, when the weld expands due to heat, the expansion displacement is blocked by the rigid pressure head and difficult to release, generating extremely high compressive stress inside the weld. When the weld cools and contracts, the material needs to shrink, but the rigid pressure head does not allow it to retract freely, causing the weld to be stretched and generating extremely high tensile stress inside. This residual welding stress caused by rigid constraints will cause the entire box to tilt slightly or the sidewalls to be uneven after welding.

[0050] See Figure 10 and Figure 11Each pressing part 46 also includes a buffer unit 401; the buffer unit 401 is disposed on the pressing part 46 and includes a limiting rod 4011, a fixing plate 4012 and a buffer part 4013; the limiting rod 4011 has multiple limiting rods and is respectively disposed on the top of the pressing drive member 45, and the limiting rod 4011 and the pressing part 46 are clearance-fitted; the fixing plate 4012 is disposed on the outside of the multiple limiting rods 4011 and is located below the pressing part 46; the buffer part 4013 has multiple buffers and is respectively sleeved on the outside of the limiting rods 4011, and both ends of the multiple buffer parts 4013 abut against the fixing plate 4012 and the bottom of the pressing part 46 respectively.

[0051] In this embodiment, the pressing part 46 has a circular opening for the output rod of the pressing drive member 45 to pass through, and the outer diameter of the output rod of the pressing drive member 45 is smaller than the circular opening. In the initial state, that is, when the pressing drive member 45 is not activated, the pressing part 46 is abutted by the buffer part 4013 and stays below the output rod of the pressing drive member 45. In this embodiment, the buffer part 4013 is preferably a telescopic spring. When the pressing drive member 45 drives the pressing part 46 to descend and fit against the higher side bending surface, the pressing part 46 can compress the buffer part 4013 sleeved on the outside of the limiting rod 4011. This compression process converts the rigid downward pressure into an elastic corrective force, which is flexibly applied to the second bending surface. During subsequent laser welding, when the second bending surface undergoes a slight upward displacement due to thermal expansion, this displacement pushes the pressing part 46 to further compress the buffer part 4013, which is absorbed without generating rigid resistance. When the weld cools and contracts, the elastic potential energy stored in the buffer part 4013 pushes the pressing part 46 downward to fill the contraction gap. This keeps the contact pressure of the pressing part 46 essentially constant, allowing the weld to solidify and cool under relatively low rigid restraint, reducing residual stress and ensuring a neat box shape after welding.

[0052] Example 4: A welding method using a welding apparatus for plate components as described above, comprising the following steps: S1. Place the plate component to be welded on the platform 31, and activate the two drive units 33 of the preliminary positioning reference mechanism 3 to drive the two left and right L-shaped positioning rotating units 32 to rotate upwards on the plate, so that the pressing ends of the two L-shaped pressure arms abut against the upper corner of one side of the plate and the lower corner of the other side, respectively, to complete the macro-fixation of the plate by diagonal pressing and establish the positioning reference. With the plate fixed, the camera on the welding equipment 2 takes pictures of the notch located at the intersection of the first bending surface and the second bending surface to obtain the size and shape information of the notch, and to determine whether there is a height difference and whether it needs to be corrected. S2. Based on the detection results of S1, when it is determined that there is a height difference and a gap, the internal support correction mechanism 4 is activated. First, the vertical drive component 42 pushes the first mating part 43 upward, extending from the bottom of the plate into the inner side of the box, so that the first abutment surface 431 and the second abutment surface 432 protruding on the first mating part 43 abut against the inner side of the first bending surface and the second bending surface on the corresponding side, forming a support reference. The clearance groove between the two abutment surfaces is directly opposite the root of the weld, avoiding the internal support force from acting directly on the root of the weld. Then, based on the height difference detected by S1, it is determined whether the first bending surface is too high or the second bending surface is too high. The four sets of horizontal moving parts 44 respectively drive the corresponding downward driving component 45, downward pressing part 46 and protruding part 47 to move as a whole to the correction position on both sides of the gap. For each gap, the downward driving component 45 located on the higher side pushes the L-shaped downward pressing part 46. As it moves downward, its first contact surface contacts the side of the high-side bending surface, and the second contact surface presses against the outer surface of the high-side bending surface, performing vertical downward pressure correction on the high-side bending surface; at the same time, the triangular protrusion 47 on the second contact surface is embedded into the weld area next to the notch during the downward pressure process, squeezing the high-side bending surface from the outside inward; the downward pressure part 46 located on the other side of the notch contacts and cooperates with the high-side bending surface, forming opposing cooperation from both sides of the notch, so that the base materials on both sides of the notch move closer together, and the notch converges and shrinks inward; during the vertical downward pressure process, the buffer unit 401 located between the downward pressure drive 45 and the downward pressure part 46 works, the downward pressure part 46 slides along the limit rod 4011 that is fitted with it, compressing the buffer part 4013 sleeved on the outside of the limit rod 4011, converting the rigid downward pressure into an elastic correction force, which is flexibly applied to the high-side bending surface; S3. After S2 has been corrected and the pressing part 46 remains elastically pressed, the welding equipment 2 performs laser welding along the weld seam to be welded. During the welding process, when the high side bending surface undergoes a slight displacement due to thermal expansion and contraction caused by the welding heat, the compressed buffer part 4013 absorbs or compensates for the displacement through its own passive expansion and contraction, so that the pressing part 46 maintains a basically constant contact pressure on the high side bending surface, and the weld seam completes solidification and cooling under a relatively rigid constraint.

[0053] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A welding apparatus for plate components, comprising a single-axis machine tool (1) and welding equipment (2) disposed beside the single-axis machine tool (1), characterized in that: The plate to be welded has a first side, a second side, and a third side. The first side is the top surface of the plate component after bending. The second side is formed by bending one side of the first side along its length, thus forming the first bending surface. The third side is formed by bending one side of the first side along its width, thus forming the second bending surface. The mating edges of the first and second bending surfaces form four weld seams to be welded. The four weld seams to be welded are welded in sequence in a clockwise or counterclockwise direction; The tops of the last two weld seams to be welded form a notch at the intersection of the first bending surface and the second bending surfaces on the left and right sides. A camera for detecting the notch is installed on the welding equipment (2); The single-axis machine tool (1) is also equipped with a preliminary positioning reference mechanism (3) and a pressing internal support correction mechanism (4); The preliminary positioning reference mechanism (3) includes a platform (31) and a positioning rotation part (32); the platform (31) is fixed on the single-axis machine tool (1) and is used to support the plate to be welded; there are two positioning rotation parts (32), which are arranged on the left and right sides of the platform (31) respectively, and are used to diagonally press and fix the plate to be welded, and provide a positioning reference for the detection of the camera. The pressing and internal support correction mechanism (4) has two sets, left and right, which are used to lift the first and second bending surfaces of the weld area to be welded from the inside and press down on the lifted part from the outside to reduce the corresponding gap.

2. The welding apparatus for plate components according to claim 1, characterized in that: Both positioning and rotating parts (32) are L-shaped pressure arms, which are respectively located on the left and right sides of the platform (31); the pressing end of the left L-shaped pressure arm abuts against the upper left corner of the plate component to be welded, and the pressing end of the right L-shaped pressure arm abuts against the lower right corner of the plate component to be welded, and the two L-shaped pressure arms form diagonal pressing in the diagonal direction of the plate component to be welded.

3. The welding apparatus for plate components according to claim 2, characterized in that: The preliminary positioning reference mechanism (3) also includes a drive unit (33); the drive unit (33) is located on the platform (31) and there are two of them, and the output ends of the two drive units (33) are respectively connected to the positioning rotation unit (32). When the drive unit (33) is started, it can drive the positioning rotation unit (32) to move upward toward the plate to be welded.

4. The welding apparatus for plate components according to claim 3, characterized in that: The pressing inner support correction mechanism (4) has two sets. The two sets of pressing inner support correction mechanisms (4) are respectively set to the notches on the left and right sides of the plate to be welded, and are both located below the platform (31) and the plate to be welded pressed onto the platform (31). Each set of internal support and correction mechanisms (4) includes a first mounting part (41), a vertical drive part (42), and a first mating part (43). The first mounting part (41) is located below the shelf (31); the vertical drive member (42) is located at the top of the first mounting part (41); the first mating part (43) is located at the output end of the vertical drive member (42), and the first mating part (43) faces the inner side of the first bending surface and the second bending surface on the corresponding side.

5. The welding apparatus for plate components according to claim 4, characterized in that: The first mating part (43) includes a first abutting surface (431) and a second abutting surface (432); both the first abutting surface (431) and the second abutting surface (432) are cuboid structures, and the end face of the cuboid structure and the inner contact surface of the plate to be welded are chamfered structures, and there is a clearance groove between the first abutting surface (431) and the second abutting surface (432), which is far away from the weld seam to be welded.

6. The welding apparatus for plate components according to claim 5, characterized in that: The first abutting surface (431) and the second abutting surface (432) are protruding on the first mating part (43), and the first abutting surface (431) and the second abutting surface (432) are higher than the top plane of the first mating part (43); the first abutting surface (431) is used to abut the inner side of the first bending surface, and the second abutting surface (432) is used to abut the inner side of the second bending surface.

7. A welding apparatus for plate components according to claim 4, characterized in that: The clamping internal support correction mechanism (4) also includes four sets of horizontal moving parts (44), four sets of downward driving parts (45), four sets of downward pressing parts (46) and four sets of protrusions (47). Among the four sets of horizontal moving parts (44), two sets correspond to the left notch and are respectively located on both sides of the notch, and the other two sets correspond to the right notch and are respectively located on both sides of the notch. Each set of horizontal moving parts (44) is slidably disposed on the shelf (31) and close to one side of the positioning rotating part (32); each set of downward driving parts (45) is disposed on the top of the corresponding horizontal moving part (44); Each pressing part (46) is slidably disposed on the outside of the output rod of the corresponding pressing drive (45), and the pressing part (46) is an L-shaped structure. The L-shaped structure has two first contact surfaces and second contact surfaces that are in contact with the plate to be welded. The first contact surface is used to contact the side of the corresponding side bending surface, and the second contact surface is used to contact the outer side of the corresponding side bending surface. Each set of protrusions (47) is provided on the corresponding second mating surface, and the protrusions (47) are triangular protrusion structures, and the protrusions (47) are close to the side of the weld to be welded.

8. A welding apparatus for plate components according to claim 7, characterized in that: Each set of pressing parts (46) also includes a horizontal mounting bracket (48) and a horizontal slide rail (49); the horizontal mounting bracket (48) is located on the top of the shelf (31) and has a pair; the horizontal slide rail (49) is slidably mounted on the horizontal mounting bracket (48), and the top of the horizontal slide rail (49) is connected to the horizontal moving part (44).

9. A welding apparatus for plate components according to claim 7, characterized in that: Each pressing part (46) also includes a buffer unit (401); the buffer unit (401) is provided on the pressing part (46), and the buffer unit (401) includes a limiting rod (4011), a fixing piece (4012) and a buffer part (4013). The limiting rod (4011) has multiple ones and is respectively provided on the top of the pressing drive (45), and the limiting rod (4011) and the pressing part (46) are in clearance fit; The fixing plate (4012) is located on the outside of the multiple limiting rods (4011), and the fixing plate (4012) is located below the pressing part (46); The buffer part (4013) has multiple parts and is respectively sleeved on the outside of the limiting rod (4011), and the two ends of the multiple buffer parts (4013) abut against the bottom of the fixing piece (4012) and the pressing part (46) respectively.

10. A method of operating a welding apparatus for plate components, using the welding apparatus as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Place the plate component to be welded on the platform (31), start the two drive units (33) of the preliminary positioning reference mechanism (3), and drive the two left and right L-shaped positioning rotating units (32) to rotate upwards on the plate, so that the pressing ends of the two L-shaped pressure arms abut against the upper corner of one side of the plate and the lower corner of the other side, respectively, and complete the macro-fixation of the plate by diagonal pressing to establish the positioning reference; when the plate is fixed, the camera on the welding equipment (2) takes pictures of the notch located at the intersection of the first bending surface and the second bending surface to obtain the size and shape information of the notch, and determine whether there is a height difference and whether it needs to be corrected; S2. Based on the detection results of S1, when it is determined that there is a height difference and a gap, the internal support correction mechanism (4) is activated. First, the vertical drive component (42) pushes the first mating part (43) to rise and extend into the inner side of the box from the bottom of the plate, so that the first abutting surface (431) and the second abutting surface (432) protruding on the first mating part (43) abut against the inner side of the first bending surface and the second bending surface on the corresponding side, forming a support reference. The clearance groove between the two abutting surfaces is directly opposite the root of the weld, so as to avoid the internal support force from acting directly on the root of the weld. Subsequently, based on the height difference detected by S1, it is determined whether the first bending surface or the second bending surface is too high; the four sets of horizontal moving parts (44) respectively drive the corresponding pressing drive (45), pressing part (46) and protrusion (47) to move as a whole to the correction position on both sides of the notch; for each notch, the pressing drive (45) located on the higher side pushes the L-shaped pressing part (46) downward, its first contact surface is in contact with the side of the bending surface on the higher side, and the second contact surface is pressed on the outer side of the bending surface on the higher side, performing vertical pressing correction on the bending surface on the higher side; at the same time, the triangular protrusion (47) on the second contact surface is pressed down during the pressing process. The weld area embedded next to the notch is squeezed from the outside to the inside of the high side bending surface; the pressing part (46) on the other side of the notch contacts and cooperates with the high side bending surface, forming a counter-cooperation from both sides of the notch, so that the base material on both sides of the notch moves closer to each other, and the notch converges and shrinks inward; during the vertical pressing process, the buffer unit (401) between the pressing drive (45) and the pressing part (46) works, the pressing part (46) slides along the limiting rod (4011) that is fitted with it, and compresses the buffer part (4013) sleeved on the outside of the limiting rod (4011), converting the rigid pressing force into an elastic correction force, which is flexibly applied to the high side bending surface; S3. After S2 is completed and the pressing part (46) is kept in an elastically pressed state, the welding equipment (2) performs laser welding along the weld seam to be welded. During the welding process, when the high side bending surface undergoes a small displacement due to thermal expansion and contraction caused by the welding heat, the compressed buffer part (4013) absorbs or compensates for the displacement through its own passive expansion and contraction, so that the pressing part (46) maintains a basically constant contact pressure on the high side bending surface, and the weld seam completes solidification and cooling under a relatively rigid constraint.

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