Transformer box edge processing method and processing equipment

Abstract

The invention discloses a transformer box edge machining method and machining equipment, a whole steel plate is adopted for welding, the size of the whole steel plate in the width direction is large, the rigidity of the whole steel plate and box edge square steel have asymmetry, the box edge square steel is a narrow strip, and the bending resistance and torsional rigidity of the box edge square steel are relatively low. And the rigidity of the whole steel plate in the plane is great. When a welding seam is cooled and contracted, huge contractility tries to pull the steel plate to deform, but the rigidity of the steel plate is enough to resist the local contractility, so that the steel plate cannot pull the whole steel plate. In addition, deformation is suppressed, which does not mean that the contractile force disappears. The force can be stored in the welding part in the form of residual stress. In other words, the materials in the welding seam area bear huge tensile stress, the surrounding steel plates bear pressure stress, a balance state is achieved on the whole, and therefore visible bending or torsional deformation is avoided macroscopically, and the leveling difficulty can be lowered.

Description

Technical Field

[0001] This application relates to the field of transformer technology, and more specifically, to a method and equipment for processing transformer tank edges. Background Technology

[0002] The tank edge of a transformer oil tank is generally made by welding three sections of square steel of different lengths onto a leveled long strip. A single set of tank edges often bends and twists due to the welding stress of the weld, requiring multiple leveling operations. This not only makes leveling difficult and inefficient, but also often causes leakage problems due to uneven weld feet.

[0003] Therefore, how to reduce the difficulty of leveling has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a method and equipment for processing the edge of a transformer box, so as to reduce the difficulty of leveling.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] In a first aspect, this application provides a method for processing the edge of a transformer box, including:

[0007] M sets of box edge square steel are welded on the whole steel plate, and each set of box edge square steel includes n box edge square steel.

[0008] The entire steel plate following the square steel of the welding box is leveled and welded.

[0009] The box is divided into m sections, each of which consists of n square steel bars.

[0010] In some embodiments, welding m sets of box-side square steel along the entire steel plate includes:

[0011] Position the entire steel plate;

[0012] The m sets of boxes are arranged and positioned on the whole steel plate along the width direction of the square steel, and the boxes extend along the length direction of the square steel.

[0013] Simultaneous welding of m×n box-edge square steel.

[0014] In some embodiments, in the simultaneous welding of m×n box edge square steel bars, welding is performed from both ends toward the middle for each box edge square steel bar.

[0015] In some embodiments, the weld height does not exceed 3 mm.

[0016] In some embodiments, the m-strip boxes are divided using a common-edge cutting method.

[0017] In some embodiments, the perpendicularity of the cut along the segmented m-strip box is less than 0.1 mm.

[0018] In some embodiments, the width of the entire steel plate is 1.5m to 3m, including the endpoints; the value of m ranges from 6 to 13, including the endpoints.

[0019] Secondly, this application provides a transformer box edge processing equipment, including a welding device, a leveling device and a dividing device. The welding device is used to weld m groups of box edge square steel on a whole steel plate, and each group of box edge square steel includes n box edge square steel.

[0020] The leveling device is used to level the entire steel plate after welding the square steel of the box.

[0021] The dividing device is used to divide the box edge into m sections, and each box edge includes n box edge square steel bars.

[0022] In some embodiments, the transformer box edge processing equipment further includes a conveying device arranged between the welding device, the leveling device, and the dividing device to convey steel plates.

[0023] In some embodiments, the leveling device includes a 7-roller or 9-roller leveling machine.

[0024] As can be seen from the above example, this application uses a single steel plate for welding. The width of this single steel plate is relatively large, resulting in an asymmetry in rigidity between the single steel plate and the box rim square steel: the box rim square steel is a narrow, long strip with relatively low bending and torsional stiffness. In contrast, the single steel plate has extremely high rigidity in the plane. When the weld cools and contracts, the enormous contraction force attempts to deform the steel plate, but the plate's inherent rigidity is sufficient to resist this localized contraction force, preventing it from "pulling" the entire plate. Furthermore, the suppression of deformation does not mean the contraction force disappears. This force is "stored" inside the welded component as residual stress. In other words, the material in the weld area bears enormous tensile stress, while the surrounding steel plate bears compressive stress, achieving an overall equilibrium. This macroscopically avoids visible bending or torsional deformation, thereby reducing the difficulty of leveling.

[0025] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 A cross-sectional schematic diagram of a whole steel plate with welded box-edge square steel provided for an embodiment of this application;

[0028] Figure 2 This is a schematic diagram of a transformer box edge processing method provided in an embodiment of this application;

[0029] Figure 3 A schematic diagram of a welding process provided in an embodiment of this application;

[0030] Figure 4 A schematic diagram of a leveling process provided in an embodiment of this application;

[0031] Figure 5 This is a schematic diagram of a transformer box edge processing device provided in an embodiment of this application;

[0032] Figure 6 A schematic diagram of a welding apparatus provided in an embodiment of this application;

[0033] Among them, 1-a whole steel plate; 2-square steel for the box edge;

[0034] 10 - Welding device; 20 - Leveling device; 30 - Dividing device;

[0035] 101-Support frame; 102-Lifting beam; 103-Welding torch; 104-Clamp; 121-Telescopic mechanism. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0037] Because current transformer box edge welding involves narrow, elongated strips, which are prone to bending and twisting deformations, multiple leveling operations are required to address these deformations in order to meet product quality standards. This process is repetitive, inefficient, and particularly challenging for leveling twisted deformations. To address this technical problem, this application discloses a method for processing transformer box edges.

[0038] See Figure 1 and Figure 2 The method for processing the transformer box edge includes:

[0039] Step S1: Weld m sets of box edge square steel 2 onto the whole steel plate 1. Each set of box edge square steel 2 includes n box edge square steel 2.

[0040] The single steel plate 1 has width, length, and thickness, where the width corresponds to the width of the single steel plate 1, the length corresponds to the length of the single steel plate 1, and the thickness corresponds to the thickness of the single steel plate 1. Unlike welding methods using narrow strips, this application uses a single steel plate 1 for welding. The single steel plate 1 has a larger width dimension, resulting in an asymmetry in rigidity between the single steel plate 1 and the box edge square steel 2: the box edge square steel 2 is a narrow strip with relatively low bending and torsional stiffness. The single steel plate 1, however, has extremely high rigidity in the plane. When the weld cools and contracts, the enormous contraction force attempts to deform the steel plate, but the steel plate's own rigidity is sufficient to resist this localized contraction force, preventing it from "pulling" the entire steel plate. Furthermore, the suppression of deformation does not mean the contraction force disappears. This force is "stored" inside the welded component as residual stress. In other words, the material in the weld area bears enormous tensile stress, while the surrounding steel plate bears compressive stress, achieving an overall equilibrium state, thus macroscopically preventing visible bending or torsional deformation.

[0041] The width of the entire steel plate 1 is 1.5m to 3m, including the endpoints. With improved processing equipment capabilities, the width of the entire steel plate 1 can be even greater. Therefore, for the above dimensions, m transformer box edges can be processed, where the value of m ranges from 6 to 13, including the endpoints. Each transformer box edge corresponds to n square steel bars.

[0042] See Figure 3 The welding process specifically includes the following steps:

[0043] Step S11: Positioning the entire steel plate 1. In some embodiments, a clamp 104 can be used during the positioning of the entire steel plate 1. Temporary clamps 104, such as C-clamps or F-clamps, can be set on the welding device 10 to temporarily clamp the workpiece, which is very flexible; or modular combination clamps 104 can be used, such as those composed of platforms, blocks, and clamps, which can quickly build a positioning system suitable for the shape of the workpiece like building blocks, with high precision and high efficiency. Magnetic clamps 104 can also be used, for example, using strong magnetic force to attract the steel plate, which is particularly suitable for positioning large flat plates and is extremely convenient to operate. In some embodiments, supports and blocks can be used during the positioning of the entire steel plate 1. The positioning block can be an iron block welded to the platform to quickly determine the edge of the workpiece; or a spiral support can be set, which can finely adjust the height to support the workpiece and correct its horizontal position; or anti-deformation (advanced positioning technique) can be applied, predicting the deformation that will occur after welding during positioning. For example, before welding a single-sided square steel plate, use a jack or clamp 104 to pre-bend the steel plate in the opposite direction at an angle (reverse deformation), and then tack weld it. In this way, after the weld cools and shrinks, the workpiece can return to a straight state.

[0044] Step S12: Arrange the m groups of boxes along the width direction of the square steel 2 on the whole steel plate 1 and position them. The boxes extend along the length direction of the square steel 2.

[0045] The positioning of the square steel 2 along the box edge can be achieved with the help of clamps 104, etc. The form of clamps 104 can be referenced to the positioning of the whole steel plate 1.

[0046] Step S13: Simultaneously weld m×n box-edge square steel bars 2.

[0047] Based on step S12, in some embodiments, m×n welding torches 103 are used to simultaneously weld m×n box rim square steel bars 2; or in some embodiments, 2m×n welding torches 103 are used to simultaneously weld m×n box rim square steel bars 2. Each box rim square steel bar 2 needs to form two weld seams with the entire steel plate 1. Each box rim direction corresponds to two welding torches 103, one welding torch 103 welds one weld seam, and the other welding torch 103 welds the other weld seam. For each of the box rim square steel bars 2, welding is performed from both ends towards the middle; welding from the middle towards both ends is also possible. To ensure welding quality, the weld height does not exceed 3mm.

[0048] Step S2: Level and weld the entire steel plate 1 along the square steel 2 of the box.

[0049] In this step, a flattening machine, also known as a leveling machine or straightening machine, is typically used for leveling. Based on the number of rollers and their operating principle, they are mainly divided into two categories: parallel roller flattening machines and presses (or plate rolling machines / three-roll plate rolling machines). Parallel roller flattening machines are the most commonly used and typical equipment. They consist of two rows of staggered work rollers. When the steel plate passes through these rollers, it undergoes repeated bending and counter-bending, much like straightening a wire by hand. This repeated plastic deformation redistributes and balances the originally uneven stress (caused by welding) within the steel plate, eliminating wavy, bent, and other deformations, resulting in a flat plate surface. For thicker steel plates, localized deformation, or in cases where a flattening machine is unavailable, presses (or plate rolling machines / three-roll plate rolling machines) use large hydraulic or mechanical presses, along with specialized flat anvils or molds, to perform "spot pressing" or "line pressing" correction on protruding or bent areas.

[0050] See Figure 4 Taking a multi-roll flatbed press as an example, the process includes the following steps:

[0051] Step S21: Preparation.

[0052] Safety inspection: Confirm that there are no foreign objects in or around the equipment and that the protective devices are in good working order.

[0053] Clean the plate surface: Remove weld slag, spatter, burrs and other hard objects from the surface of the steel plate to prevent them from damaging the surface of the leveling roller.

[0054] Confirm steel plate specifications: Determine the material, thickness, and original state (degree of deformation) of the steel plate in order to set equipment parameters.

[0055] Step S22: Equipment parameter setting.

[0056] This is the most crucial step, and the core is adjusting the roll gap and the amount of reduction.

[0057] Adjust the roll gap: Set the gap (roll gap) between the upper and lower rows of work rolls to be slightly smaller than the actual thickness of the steel plate. This "slightly smaller" amount is the reduction amount, which allows the steel plate to undergo sufficient plastic deformation as it passes through.

[0058] Principle: The thicker and stronger the sheet metal, the greater the required reduction. It's generally advisable to start with a smaller reduction for trial runs, gradually increasing it based on the results, to avoid overloading the equipment or damaging the steel sheet at once.

[0059] Adjusting the support rollers: For precision flatbed machines, it is also necessary to adjust the support rollers to eliminate the deflection deformation of the work rollers caused by the force, and ensure that the leveling effect is consistent throughout the width of the plate.

[0060] Step S23: Trial calibration and formal calibration.

[0061] Trial calibration: Take a small piece of scrap board of the same material as the workpiece for trial calibration, or send the end of the workpiece into the machine to preliminarily check the flatness and fine-tune the roller gap and pressing amount.

[0062] Formal calibration:

[0063] Feeding the steel plate: Smoothly feed the steel plate into the rollers. For long plates, an overhead crane or feeding table may be required.

[0064] Multiple passes: For severely deformed steel plates, multiple passes through the leveling machine are usually required. The first pass aims to eliminate most of the deformation, while subsequent passes use smaller reductions for fine leveling to achieve a higher degree of flatness.

[0065] Changing direction: Sometimes it is necessary to rotate the steel plate 90 degrees and pass it through again to correct the deformation perpendicular to the rolling direction.

[0066] Step S24: Inspection and post-processing.

[0067] Check flatness: Place the leveled steel plate on the platform and use a straightedge or feeler gauge to check whether its flatness meets the requirements of the drawings or process.

[0068] Post-processing: If it passes the test, it can proceed to the next process. If it is still uneven, it needs to be returned for re-leveling.

[0069] Step S3: Divide the box edge into m sections, each section consisting of n square steel bars 2. Dividing can be achieved using methods such as flame cutting (gas cutting), plasma cutting, laser cutting, or shearing (shearing machine).

[0070] To reduce material waste, common-edge cutting is used when dividing the m-packs. Furthermore, the perpendicularity of the cut is less than 0.1 mm when dividing the m-packs.

[0071] See Figure 5 This application provides a transformer box edge processing equipment, including a welding device 10, a leveling device 20, and a dividing device 30. The welding device 10 is used to weld m groups of box edge square steel bars 2 on a whole steel plate 1, each group of box edge square steel bars 2 including n box edge square steel bars 2; the leveling device 20 is used to level the whole steel plate 1 after welding the box edge square steel bars 2; the dividing device 30 is used to divide into m box edges, each box edge including n box edge square steel bars 2.

[0072] The transformer box processing configuration of this application allows for welding of a single sheet of steel plate 1. However, the sheet of steel plate 1 has a large width, resulting in an asymmetry in rigidity between it and the square steel 2 along the box edge. The square steel 2 is a narrow strip with relatively low bending and torsional stiffness, while the sheet of steel plate 1 exhibits extremely high rigidity in the plane. When the weld cools and contracts, the enormous contraction force attempts to deform the steel plate, but the steel plate's inherent rigidity is sufficient to resist this localized contraction force, preventing it from "pulling" the entire plate. Furthermore, the suppression of deformation does not mean the contraction force disappears. This force is "stored" within the welded component as residual stress. In other words, the material in the weld area bears enormous tensile stress, while the surrounding steel plate bears compressive stress, achieving an overall equilibrium. This macroscopically prevents visible bending or torsional deformation, thereby reducing the difficulty of leveling.

[0073] The welding device 10 of this application can be used for welding square steel. The welding device 10 may include a support frame 101, a lifting beam 102, a welding torch 103, and a clamp 104. The support frame 101 supports the entire steel plate 1. The lifting beam 102 is located above the support frame 101 and is used to mount the welding torch 103. The clamp 104 is mounted on the support frame 101 and is used to position the entire steel plate 1 and / or the box-edge square steel 2. It can be a temporary clamp, such as a C-clamp or F-clamp, for temporarily clamping the workpiece, which is very flexible; or a modular combination clamp, such as one composed of a platform, stops, and clamps, can be used to quickly construct a positioning system suitable for the workpiece shape, like building blocks, with high precision and efficiency. Magnetic clamps can also be used, for example, using strong magnetic force to attract steel plates, which is particularly suitable for positioning large flat plates and is extremely convenient to operate. In some embodiments, supports and stops can be used during the positioning of the entire steel plate 1. The positioning stops can be iron blocks welded to the platform for quickly determining the workpiece edge; or spiral supports can be installed, with adjustable height, to support the workpiece and correct its horizontal position; or reverse deformation (an advanced positioning technique) can be applied, anticipating the deformation that will occur after welding during positioning. For example, before welding a single-sided square steel plate, the steel plate is pre-bent in the opposite direction at an angle (reverse deformation) using jacks or clamps, and then tack-fixed. This allows the workpiece to return to a straight state after welding, cooling, and shrinking.

[0074] To facilitate adjustment of the distance between the welding torch 103 and the support frame 101, the welding device may further include a telescopic mechanism 121. The telescopic mechanism 121 is positioned between the base and the lifting beam 102, or between the support frame 101 and the lifting beam 102. The telescopic movement adjusts the distance between the welding torch 103 and the support frame 101, thereby adjusting the distance between the welding torch 103 and the box edge square steel. The number of welding torches 103 is twice the number of box edge square steel 2. For example, when there are 18 box edge square steel 2, the number of welding torches 103 is 36, with each pair of welding torches 103 corresponding to one box edge square steel 2.

[0075] The transformer box processing equipment also includes a conveying device, which is arranged between the welding device 10, the leveling device 20, and the dividing device 30 to convey steel plates. This conveying device may be a conveying roller.

[0076] The leveling device 20 includes a parallel roller platen and a press (or a plate rolling machine / three-roll plate rolling machine). Specifically, the leveling device 20 includes a 7-roll or 9-roll leveling machine.

[0077] A method for manufacturing transformer enclosure edges includes a whole steel plate 11 and square steel bars 2. Square steel bars 2 are welded onto the whole steel plate 11 in proportion. The square steel bars of corresponding sizes and spacing can be set according to the drawings. In this embodiment, referring to the attached drawings, the first layer of 12mm square steel bars is welded onto the whole steel plate 1 with a thickness of 30mm and a thickness of 2500mm×12000mm. The distance between the first layer and the second layer of 16mm square steel bars is 34mm. The distance between the second layer and the third layer of 16mm square steel bars is 67mm. 10mm is left on the outer side of the left enclosure edge and 30mm is left on the inner side of the right enclosure edge (including a 1mm slit). After cutting, the total width of one set of enclosure edges is 184mm. A total of 13 sets of enclosure edges of this size with a length of 156 meters can be manufactured from one steel plate, which is about the amount of enclosure edges used for 7 medium-sized transformers.

[0078] The entire steel plate is 30mm thick and 2500mm×12000mm in size. It is leveled and the oxide scale is removed. The square steel is between 6mm×mm and 16mm×16mm in size, with the length matching the steel plate. It is degreased.

[0079] Fix the square steel bars with magnetic clamps 104, ensuring that the square steel bar group is perpendicular to the steel plate, and fix three square steel bars as a group according to the distance required by the drawing.

[0080] A multi-welding gun 103 welding system is used, with each pair of welding guns 103 responsible for one square steel bar. Continuous symmetrical welding is used to reduce deformation, such as welding from both sides inward or from the middle to both sides.

[0081] After all square steel bars are welded, the entire steel plate is fed into a 7-roll or 9-roll leveling machine for leveling to ensure flatness ≤1mm / m.

[0082] Based on the total width of a single group of square steel bars (width of 3 square steel bars + gap between 2 square steel bars + 10mm reserved on the outside + 10-50mm reserved on the inside + cutting distance of 1-3mm) and the length of the tank edge, the laser cutting program optimizes the layout to reduce waste generation. The cutting speed is 8~12m / min, the verticality of the cut is ≤0.1mm, and there is no slag residue.

[0083] A laser scanner was used to check the parallelism of the square steel assemblies, and a 5x magnifying glass was used to inspect the surface quality of the welds.

[0084] Six transformer box edges were machined according to the steps described above, as shown in the table below:

[0085]

[0086] The terms "first" and "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units may include steps or units not listed, but rather not listed.

[0087] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for processing the edge of a transformer box, characterized in that, include: M sets of box edge square steel are welded on the whole steel plate, and each set of box edge square steel includes n box edge square steel. The entire steel plate following the square steel of the welding box is leveled and welded. The box is divided into m sections, each of which consists of n square steel bars.

2. The processing method as described in claim 1, characterized in that, The welding of m sets of box-shaped steel along the entire steel plate includes: Position the entire steel plate; The m sets of boxes are arranged and positioned on the whole steel plate along the width direction of the square steel, and the boxes extend along the length direction of the square steel. Simultaneous welding of m×n box-edge square steel.

3. The processing method as described in claim 2, characterized in that, In the simultaneous welding of m×n box edge square steel bars, for each box edge square steel bar, welding is performed from both ends toward the middle.

4. The processing method as described in claim 1, characterized in that, The weld height shall not exceed 3mm.

5. The processing method as described in claim 1, characterized in that, The m-strip boxes are cut using a common-edge cutting method.

6. The processing method as described in claim 1, characterized in that, The perpendicularity of the cut along the m-strip section is less than 0.1 mm.

7. The processing method as described in claim 1, characterized in that, The width of the entire steel plate is 1.5m to 3m, including the endpoints; the value of m ranges from 6 to 13, including the endpoints.

8. A transformer box edge processing device, characterized in that, It includes a welding device, a leveling device, and a dividing device. The welding device is used to weld m groups of box edge square steel bars on a whole steel plate, and each group of box edge square steel bars includes n box edge square steel bars. The leveling device is used to level the entire steel plate after welding the square steel of the box. The dividing device is used to divide the box edge into m sections, and each box edge includes n box edge square steel bars.

9. The transformer box edge processing equipment as described in claim 8, characterized in that, The transformer box processing equipment also includes a conveying device, which is arranged between the welding device, the leveling device and the dividing device to convey steel plates.

10. The transformer box edge processing equipment as described in claim 8, characterized in that, The leveling device includes a 7-roller or 9-roller leveling machine.

Images