A method for manufacturing a large-scale truss sheet body and a profile correction tool used thereby

Abstract

This invention discloses a method for manufacturing large-scale truss panels and a profile straightening fixture used therein. The manufacturing method enables precise control of welding deformation of the panel truss, meeting weld quality and dimensional accuracy requirements, and achieving efficient assembly and welding of similar panel trusses. The profile straightening fixture effectively solves the problem of hooked ends on the flanges after forming, ensuring smooth assembly and welding processes. This invention employs a straightening method combining rigid fixing and flame straightening to achieve rapid and efficient straightening of batches of channel steel. By adopting this method, the straightening cycle, equipment, and manpower input after truss assembly and welding are reduced, single-piece manufacturing efficiency is increased by more than 30%, and manufacturing costs are reduced by 20%, bringing positive impacts to enterprise production and development. Compared with existing technologies, this method has excellent market prospects and development space.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of large steel structure manufacturing, and particularly relates to a large-scale truss sheet manufacturing method and profile correction tool. BACKGROUND

[0002] The large-scale truss sheet is generally composed of profiles (channel steel, I-beam, etc.) and steel plates. In general, the steel structure truss is mainly applied to the engineering technical field, and the shape and position accuracy requirement is low. The large-scale truss sheet has high size and shape and position accuracy requirements. The truss sheet is mainly composed of channel steel, I-beam and steel plates. The thickness of the profile steel (channel steel and I-beam) is 6-10 mm, the outer contour size is 12 m in length and 2 m in width, and the structural schematic diagram is shown in FIG. 1. Figure 1 The deformation after assembly and welding is less than or equal to 5 mm, and the flatness is less than or equal to 3 mm. The structure is poor in rigidity, and welding deformation such as side bending and warping occurs during welding. It is difficult to guarantee the strict shape and position tolerance requirement by using the conventional assembly and welding method, which puts forward higher requirements on the manufacturing method.

[0003] How to design a method which is feasible, simple to operate, can realize accurate assembly and welding deformation control of the sheet-shaped truss, meet the welding quality and size accuracy, and can also realize efficient assembly and welding manufacturing of similar sheet-shaped trusses, improve the production efficiency and economic benefits is a technical problem to be solved at present. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a large-scale truss sheet manufacturing method and control method to solve the problems mentioned in the background.

[0005] A large-scale truss sheet manufacturing method, comprising the following steps, Step one, laying the plate and adjusting the workbench surface; the thick steel plate is laid on the workbench surface, and the flatness of the workbench surface is adjusted and controlled; Step two, part correction, the profile correction tool and correction method are used to correct the truss batch profiles; Step three, line marking after correction, the position line of each profile of the large-scale truss is drawn on the steel plate by using a stone pen and powder line lofting, and the welding shrinkage is reserved in advance in the length direction profile; the welding shrinkage is evenly distributed to the positioning size of each beam according to the length direction center line as the reference during line marking; the welding shrinkage is not reserved in the width direction, and the line marking is performed according to the drawing size; Step four, assembly. First, assemble the truss panels according to the marked ground lines, leaving the end profiles unassembled for now. During assembly, ensure the gaps between each component and strictly assemble according to the position lines to control straightness, perpendicularity, and parallelism. Draw the center lines of the length and width of the panel truss during assembly, and transfer the center lines to the side channel steel surface, punching center holes on all sides. Then, use a laser level to check the flatness of the panel truss. After passing the inspection, transfer each truss panel to electric welding. Step 5: Welding. Before welding, the area around the bevel to be welded, within twice the plate thickness, is ground smooth. The welded plate truss uses shielded gas welding, and flux-cored welding wire is used. During welding, the weld is rotated to ensure all weld seams are in a flat welding position. Welding is performed simultaneously and symmetrically by two welders from the center outwards. Welding uses low heat input and multiple layers / passes. After welding, the weld seams are inspected using non-destructive testing to ensure the weld quality meets requirements. Step Six: Assemble the ends. After completing the welding in Step Five above, measure the total length of the sheet truss and weld the end profiles after it meets the requirements. Through the precise control of the deformation of the batch steel profiles in the previous step, it is ensured that the truss can meet the form and position tolerance requirements of deformation ≤5mm and flatness ≤3mm after the overall assembly and welding without correction.

[0006] As a further optimization of the above-mentioned method for manufacturing large-scale truss panels, in step one, the flatness of the workbench surface is controlled within 1.5mm.

[0007] As a further optimization of the above-mentioned method for manufacturing large-scale truss panels, the profile straightening method in step two is as follows: First, determine the positioning plate according to the web size of the profile, place the profile to be straightened upside down in the positioning plate, use the pressure plate and clamp to press the web of the channel steel onto the workbench, and at the same time, use the wedge plate to tighten the flange side. Then, pull a powder line to re-measure the straightness of the profile, and finally, perform flame straightening on the flange of the profile according to its deformation.

[0008] As a further optimization of the above-mentioned method for manufacturing large-scale truss panels, step four ensures that the gap between each component is no greater than 1mm during assembly.

[0009] As a further optimization of the above-mentioned method for manufacturing large-scale truss panels, CO2 gas is used as the shielding gas during step five welding. The welding sequence is as follows: weld the bevel weld between the H-beam in the width direction and the continuous H-beam crossbeam → weld the bevel weld between the H-beam in the width direction and the two continuous channel steel crossbeams → weld the bevel weld between the H-beam in the width direction and the diagonal H-beam → weld the vertical weld between the H-beam in the width direction and the continuous crossbeam.

[0010] A profile straightening fixture includes a clamp, a pressure plate, two front and rear positioning plates, wedges, and bolts. The two positioning plates are fixed to the workbench, with their center lines aligned. The middle portion of each positioning plate is recessed to form a clamping part for engaging channel steel. Wedges are placed in the gap between the channel steel flange and the positioning plates to firmly fix both sides of the channel steel flange. The clamp is a C-shaped structure, with its lower end engaging the bottom plate of the workbench and its upper end positioned above the workbench. Bolts pass through threaded holes at the upper end of the clamp, and a pressure plate is provided at the lower end of the bolts. Tightening the bolts fixes the channel steel web plate below the pressure plate. The ends of the channel steel flanges are flame-straightening areas. After the channel steel is fixed as a whole, the flanges are flame-straightened according to the deformation at the ends.

[0011] Beneficial effects Compared with the prior art, the present invention has significant advantages and beneficial effects, achieving considerable technological progress and practicality, and possessing broad application value. It has at least the following advantages: 1. This invention provides a method for manufacturing large-scale truss panels. This method can achieve precise control of the welding deformation of the panel truss, meet the requirements of weld quality and dimensional accuracy, and can also achieve efficient welding and manufacturing of similar panel trusses, with extremely significant results.

[0012] 2. The present invention also provides a profile straightening fixture, which effectively solves the problem of hooking at both ends of the formed flange, and provides a guarantee for subsequent assembly and welding processes.

[0013] 3. Large-scale truss fabrication: By pre-reserving welding shrinkage allowance in the length direction of the main long steel sections, and not reserving welding shrinkage allowance in the width direction of the steel sections; laying large steel plates for ground layout and assembly, the end profiles are not welded first, and are finally welded after the remaining parts are welded and straightened; during welding, low heat input welding method and a reasonable welding sequence are used to effectively control welding deformation.

[0014] 4. This invention adopts a straightening method that combines rigid fixing and flame straightening. Specifically, a special positioning fixture is designed according to the profile dimensions of the channel steel. The profile to be straightened is placed upside down in the positioning plate. The channel steel to be straightened is fixed firmly using pressure plates, clamps, and wedges. After re-measuring the straightness and deformation by powder line, a local flame straightening method is used to achieve rapid and efficient straightening of a batch of channel steel.

[0015] 5. This invention can produce many beneficial effects in practical applications. By adopting this method, the correction cycle, equipment and manpower input after the truss assembly is welded together are reduced, the single-piece production efficiency is increased by more than 30%, and the manufacturing cost is reduced by 20%, which brings positive impacts to the production and development of enterprises. Attached Figure Description

[0016] Figure 1A schematic diagram of a large-scale truss sheet structure; Figure 2 This is a schematic diagram illustrating the actual application effect of the profile straightening fixture of the present invention; Figure 3 A schematic diagram illustrating the use of powder lines to assist in the re-measurement of deformation. Figure 4 This is a schematic diagram of the layout and marking process; Figure 5 A schematic diagram of the assembled truss panel; Figure 6 This is a schematic diagram showing the welding of the truss in its horizontal position and a partial enlarged view. Figure 7 A schematic diagram showing the side-mounted welding of the truss and a partially enlarged view; Figure 8 This is a schematic diagram of the truss panel assembly. Figure 9 A top view of the profile straightening fixture; Figure 10 This is a side view schematic diagram of the profile straightening fixture; In the diagram: 1. Workbench, 2. Clamp, 3. Bolt, 4. Pressure plate, 5. Positioning plate, 6. Wedge, 7. Channel steel web, 8. Channel steel flange, 9. Flame straightening area. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art, without creative effort, including formal modifications to the technical solutions described in the following embodiments or equivalent substitutions of some technical features, based on the inspiration of the present invention, are within the scope of protection of the present invention.

[0018] Example Please see Figures 1 to 10 , Figure 1 This is a schematic diagram of a large-scale truss panel structure, which has high requirements for dimensional and positional accuracy. The truss panel is mainly composed of channel steel, I-beams, and steel plates welded together. The thickness of the steel sections (channel steel and I-beams) is 6-10mm, and the outer contour dimensions are 12m in length and 2m in width. See the attached structural schematic diagram. Figure 1 The deformation after welding is ≤5mm, and the flatness is ≤3mm. This structure has poor rigidity, and welding deformations such as lateral bending and warping may occur during welding. Conventional welding methods are unlikely to guarantee its strict dimensional and positional tolerance requirements. To solve the above problems, this invention employs a straightening method combining rigid fixing and flame straightening. Specifically, a specialized positioning fixture is designed based on the channel steel's outline dimensions. The profile to be straightened is placed upside down in the positioning plate, and the channel steel is firmly fixed using pressure plates, flanges, and wedges. After re-measuring straightness and deformation using a powder line, localized flame straightening is performed, achieving rapid and efficient straightening of batches of channel steel. The specific implementation steps are as follows. Step 1: Laying the plate. Level the workbench surface, controlling the flatness to within 1.5mm. Lay a 16m long, 2.6m wide, and 50mm thick steel plate on the workbench surface and adjust it to be flat.

[0019] Step Two: Part Straightening. The channel steel profile is cold-pressed using a steel plate joining tool. To address the hooking phenomenon at both ends of the flange after forming, a profile straightening fixture and method were invented: A positioning plate is set according to the web size of the profile (a gap is reserved in the positioning plate for easy profile placement). The profile to be straightened is placed upside down in the positioning plate. The web of the channel steel is pressed tightly onto the platform using pressure plates and clamps. Simultaneously, wedge plates are used to tighten the flange sides. The specific fixture is as follows: Figure 2 As shown. Draw a pink thread, as... Figure 3 As shown, the straightness of the profile was re-measured, and the flange was flame-straightened according to its deformation. The flame-straightened area is shown in the figure. Figure 2 As shown. The above method can achieve batch straightening of profiles, and the flatness and straightness after straightening can be controlled within 2mm.

[0020] As attached Figure 2 , 9 As shown in Figure 10, the profile straightening fixture mentioned in step two above includes a clamp 2, a pressure plate 4, two front and rear positioning plates 5, a wedge 6, and a bolt 3. The two front and rear positioning plates 5 are fixed on the workbench 1, and the center lines of the two positioning plates 5 are aligned. The middle part of the positioning plate 5 is recessed inward to form a clamping part for clamping the channel steel web 7. The wedge 6 is placed in the gap between the channel steel wing plate 8 and the positioning plate 5 to firmly fix both sides of the channel steel wing plate 8. The clamp 2 is a C-shaped structural component. The lower end of the clamp 2 is clamped to the bottom plate of the workbench 1, and the upper end of the clamp 2 is located above the workbench 1. The bolt 3 passes through the threaded hole at the upper end of the clamp 2, and the lower end of the bolt 3 is provided with a pressure plate 4. By tightening the bolt 3, the channel steel web 7 is fixed below the pressure plate 4. The end of the channel steel wing plate 8 is the flame straightening area 9. After the channel steel is fixed as a whole, the channel steel wing plate 8 is flame straightened according to the deformation of the end.

[0021] Step 3: Marking. Use a chalk and powder to lay out the positions of each section of the large-scale truss on the steel plate. Using powder, mark the sections along the entire length by adding 15mm to the length as a pre-planned allowance for welding shrinkage. Figure 4As shown. When marking lines, use the centerline along the length direction as a reference to evenly distribute the 15mm welding shrinkage allowance across the positioning dimensions of each crossbeam. No welding shrinkage allowance is reserved in the width direction; simply mark lines according to the dimensions on the drawing.

[0022] Step Four: Assembly. Correctly selecting the assembly sequence is a powerful measure to prevent welding deformation. First, assemble the truss panels according to the marked layout lines. During assembly, do not assemble the end profiles immediately. Figure 5 As shown. During assembly, ensure that the gap between each component is no greater than 1mm, and strictly assemble according to the position lines to control straightness, perpendicularity, and parallelism. During assembly, draw the center lines in the length and width directions of the truss panels, transfer these center lines to the side channel steel surface, and punch center holes on all sides. Then, use a laser level to check the flatness of the truss panels. After passing the inspection, weld each truss panel together.

[0023] Step 5: Welding. Before welding, grind the area around the bevel to be welded to a thickness of 2 times the plate thickness until smooth. Welding of the sheet truss uses CO2 gas shielded welding, with Φ1.2mm flux-cored wire, YJ501-1, as the welding material. During welding, rotate the weld to ensure all weld joints are in a flat welding position. Welding sequence: Weld the bevel weld between the width-direction H-beam (part 2) and the continuous H-beam crossbeam (part 1) (e.g., ...). Figure 6 (Middle weld 1 and similar) → Bevel weld between the H-beam (part 2) and the two continuous channel beams (part 3) in the welding width direction (such as...) Figure 6 (Medium weld 2 and similar) → Bevel weld between the H-beam (part 2) and the oblique H-beam (part 4) in the welding width direction (such as...) Figure 6 (Middle weld 3 and similar) → Vertical weld between the I-beam (part 2) and the continuous crossbeam (parts 1 and 3) in the welding width direction (as shown in welds 4 and 5 and similar, the plate truss is flipped and upright, and the welding position is flat welded, such as...) Figure 7 (As shown). Welding is performed simultaneously and symmetrically by two welders from the center outwards. Low heat input and multi-layer, multi-pass welding are employed. After welding, non-destructive testing is performed on the weld to ensure that the weld quality meets requirements.

[0024] Step Six: Assemble the Ends. After completing all the above welds, measure the total length of the sheet truss and, if it meets the requirements, weld the end profiles. After welding, the sheet truss should look like this. Figure 8 As shown. Through precise control of the deformation of the batch steel sections, it can be ensured that the truss can meet the form and position tolerance requirements of deformation ≤5mm and flatness ≤3mm without correction after the overall assembly and welding.

[0025] 1. This invention provides a method for manufacturing large-scale truss panels. This method can achieve precise control of the welding deformation of the panel truss, meet the requirements of weld quality and dimensional accuracy, and can also achieve efficient welding and manufacturing of similar panel trusses.

[0026] 2. The present invention also provides a profile straightening fixture, which effectively solves the problem of hooking at both ends of the formed flange, and provides a guarantee for subsequent assembly and welding processes.

[0027] 3. Large-scale truss fabrication: By pre-reserving welding shrinkage allowance in the length direction of the main long steel sections, and not reserving welding shrinkage allowance in the width direction of the steel sections; laying large steel plates for ground layout and assembly, the end profiles are not welded first, and are finally welded after the remaining parts are welded and straightened; during welding, low heat input welding method and a reasonable welding sequence are used to effectively control welding deformation.

[0028] 4. This invention adopts a straightening method that combines rigid fixing and flame straightening. Specifically, a special positioning fixture is designed according to the profile dimensions of the channel steel. The profile to be straightened is placed upside down in the positioning plate. The channel steel to be straightened is fixed firmly using pressure plates, clamps, and wedges. After re-measuring the straightness and deformation by powder line, a local flame straightening method is used to achieve rapid and efficient straightening of a batch of channel steel.

[0029] 5. This invention can produce many beneficial effects in practical applications. By adopting this method, the correction cycle, equipment and manpower input after the truss assembly is welded together are reduced, the single-piece production efficiency is increased by more than 30%, and the manufacturing cost is reduced by 20%, which brings positive impacts to the production and development of enterprises.

[0030] This invention's manufacturing method enables precise control of welding deformation in sheet trusses, ensuring weld quality and dimensional accuracy. It also facilitates efficient welding of similar sheet trusses. The profile straightening fixture effectively solves the hooking problem at both ends of the formed flanges, guaranteeing subsequent assembly and welding processes. This invention employs a combination of rigid fixing and flame straightening to achieve rapid and efficient straightening of batches of channel steel. By adopting this method, the straightening cycle, equipment, and manpower input after truss assembly and welding are reduced, single-piece production efficiency is increased by over 30%, and manufacturing costs are reduced by 20%, bringing positive impacts to enterprise production and development. Compared to existing technologies, this method has excellent market prospects and development potential.

[0031] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the concept of the present invention.

Claims

1. A method for manufacturing a large-scale truss sheet, characterized in that: Includes the following steps, Step 1: Lay the plate and level the workbench; Lay the thick steel plate on the workbench and adjust and control the flatness of the workbench. Step 2, parts straightening: straightening the truss profiles in batches using profile straightening fixtures and methods; Step 3: After correction, mark the lines. Use a chalk and chalk line to lay out the position lines of each profile of the large-scale truss on the steel plate. Use chalk line to mark the lines. Allow for welding shrinkage in advance for the steel profiles along the entire length. When marking the lines, use the center line of the length direction as a reference to evenly distribute the welding shrinkage to the positioning dimensions of each beam. Do not allow for welding shrinkage in the width direction. Mark the lines according to the dimensions in the drawings. Step four, assembly. First, assemble the truss panels according to the marked ground lines, leaving the end profiles unassembled for now. During assembly, ensure the gaps between each component and strictly assemble according to the position lines to control straightness, perpendicularity, and parallelism. Draw the center lines of the length and width of the panel truss during assembly, and transfer the center lines to the side channel steel surface, punching center holes on all sides. Then, use a laser level to check the flatness of the panel truss. After passing the inspection, transfer each truss panel to electric welding. Step 5: Welding. Before welding, the area around the bevel to be welded, within twice the plate thickness, is ground smooth. The welded plate truss uses shielded gas welding, and flux-cored welding wire is used. During welding, the weld is rotated to ensure all weld seams are in a flat welding position. Welding is performed simultaneously and symmetrically by two welders from the center outwards. Welding uses low heat input and multiple layers / passes. After welding, the weld seams are inspected using non-destructive testing to ensure the weld quality meets requirements. Step Six: Assemble the ends. After completing the welding in Step Five above, measure the total length of the sheet truss and weld the end profiles after it meets the requirements. Through the precise control of the deformation of the batch steel profiles in the previous step, it is ensured that the truss can meet the form and position tolerance requirements of deformation ≤5mm and flatness ≤3mm after the overall assembly and welding without correction.

2. The method for manufacturing a large-scale truss sheet as described in claim 1, characterized in that: In step one, the flatness of the workbench surface is controlled within 1.5mm.

3. The method for manufacturing a large-scale truss sheet as described in claim 1, characterized in that: The profile straightening method in step two is as follows: First, determine the positioning plate according to the web size of the profile, place the profile to be straightened upside down in the positioning plate, use the pressure plate and clamp to press the web of the channel steel onto the workbench, and at the same time use the wedge plate to tighten the flange side. Then, pull a powder line and re-measure the straightness of the profile. Finally, perform flame straightening on the flange of the profile according to its deformation.

4. The method for manufacturing a large-scale truss sheet as described in claim 1, characterized in that: During the assembly process in step four, ensure that the gap between each component is no greater than 1mm.

5. The method for manufacturing a large-scale truss sheet as described in claim 1, characterized in that: In step five, CO2 gas is used as the shielding gas. The welding sequence is as follows: weld the bevel weld between the H-beam and the continuous H-beam beam in the width direction → weld the bevel weld between the H-beam and the two continuous channel beams in the width direction → weld the bevel weld between the H-beam and the diagonal H-beam in the width direction → weld the vertical weld between the H-beam and the continuous beam in the width direction.

6. A profile straightening fixture based on the method of any one of claims 1 to 5, characterized in that: The straightening fixture includes a clamp, a pressure plate, two front and rear positioning plates, wedges, and bolts. The two positioning plates are fixed to the workbench, with their center lines aligned. The middle part of the positioning plates is recessed to form a clamping part for engaging the channel steel. Wedges are placed in the gap between the channel steel flange and the positioning plate to firmly fix both sides of the channel steel flange. The clamp is a C-shaped structure. The lower end of the clamp engages with the bottom plate of the workbench, and the upper end of the clamp is located above the workbench. Bolts pass through the threaded holes at the upper end of the clamp, and a pressure plate is provided at the lower end of the bolts. Tightening the bolts fixes the channel steel web plate under the pressure plate. The ends of the channel steel flanges are flame straightening areas. After the channel steel is fixed as a whole, the flanges are flame straightened according to the deformation of the ends.

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