Gasket positioning device for welding steel structural member

Abstract

The utility model relates to the field of steel structural part welding processes, in particular to a gasket positioning device for steel structural part welding. The technical problem to be solved by the utility model is to provide the gasket positioning device for welding the steel structural member, which is suitable for welding a welding seam under the condition that a gap between a first steel member to be welded and a second steel member to be welded is relatively large. According to the technical scheme, the gasket positioning device for welding the steel structural part comprises a connecting rod, a magnetic support is arranged at one end of the connecting rod, a magnetic part is fixedly arranged on the magnetic support, the thickness of the magnetic support is equal to the size of a gap between a gasket plate and the steel structural part, and the magnetic part is fixedly arranged on the magnetic support. A handle is arranged at the other end of the connecting rod. The welding device is particularly suitable for welding process occasions with large welding gaps of cylindrical steel structural parts.

Description

Technical Field

[0001] The utility model relates to the field of steel structure welding technology, in particular to a liner positioning device used for welding steel structure. Background Art

[0002] Large cylindrical steel structure components, such as steel pipe piles, hollow steel pipe arches for bridges, large pipe trusses, metallurgical system components, etc., involve butt welding of round pipe components during manufacturing and installation. After welding is completed, non-destructive testing is required to determine the weld qualification. If defects are found during the inspection, the weld needs to be planed and reworked, resulting in losses in welding auxiliary materials, welding energy, labor, construction period, etc. The common single-sided welding and double-sided forming welding process is mainly ceramic liner welding. This type of method has the following main disadvantages: 1. The welding cost caused by the ceramic liner itself increases significantly; 2. The ceramic liner has no adhesion to the cladding metal, and the cladding metal in the molten pool is easy to slide off, especially in horizontal welding, vertical welding, overhead welding and other welding positions; 3. The ceramic liner is attached to the surface of the parent material with adhesive. After welding and heating, the adhesive of the ceramic liner itself is easy to fall off, especially in the flat welding position. After heating, the liner is more likely to fall off under the action of gravity in the molten pool, which has an adverse effect on the welding process; The ceramic liner has certain requirements for the size of the weld gap of the parent material assembly. The uneven gap has a greater impact on the welding qualification rate, and larger gaps cannot be welded; 4. When assembling steel pipe segments on site, it is necessary to enter the hall pipe to paste the ceramic liner, which is cumbersome.

[0003] Taking the patent with publication number CN108687428A, entitled "Single-sided welding and double-sided forming fillet welding submerged arc welding method" as an example, a common welding process is involved. When butt-jointing cylindrical steel structural parts, a single-sided welding and double-sided forming process with ceramic pads is adopted. However, during the welding process, the adhesive of the ceramic pads is easy to fall off, which has a great impact on the welding progress and quality. During the assembly and installation welding process of cylindrical steel components, the same butt joint may involve butt welds of horizontal welding, vertical welding, overhead welding and other welding positions. These welds use ceramic pads, which have no adhesion to the cladding metal, and the welding position changes with the shape, which requires high welding skills and increases the difficulty of welding. Especially for butt joints during on-site installation, it is necessary to paste and install the ceramic pad inside the pipe, which is not conducive to improving construction efficiency, and there are construction safety hazards in the operation inside the box. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a liner positioning device for welding steel structural parts, which is suitable for welding of weld seams when the gap between a first steel component to be welded and a second steel component is relatively large.

[0005] The technical solution adopted by the present utility model to solve its technical problems is as follows: a gasket positioning device for welding steel structure parts. The gasket positioning device includes a connecting rod. One end of the connecting rod is provided with a magnetic support, and a magnetic member is fixedly arranged on the magnetic support. The thickness of the magnetic support is equal to the size of the gap between the gasket and the steel structure part. The other end of the connecting rod is provided with a handle.

[0006] Further, the magnetic support includes a fixed side and a positioning side. The fixed side and the positioning side are perpendicular to each other to form an L shape. The fixed side of the magnetic support is fixedly arranged at the end of one end of the connecting rod, and the magnetic member is arranged on the positioning side of the magnetic support. The thickness of the positioning side of the magnetic support is equal to the size of the gap between the gasket and the steel structure part.

[0007] Further, the magnetic member is a neodymium iron boron permanent magnet sheet.

[0008] Further, the connecting rod is of a bent structure, and the extending direction of the axis of the handle is parallel to the extending direction of the positioning side of the magnetic support.

[0009] Further, the dimensional parameters of the gasket are as follows: thickness t: 5 ≤ t ≤ T / 2, unit mm, where T is the wall thickness of the butt-welded steel pipe; theoretical radius r' of the gasket roll: r' = R - T - 2, unit mm, where R is the outer wall radius of the current steel pipe and T is the wall thickness of the butt-welded steel pipe, and the allowable deviation of the gasket radius is [-5%, 0); arc length a of the gasket: πr / 3 ≤ a ≤ (180° - arccos(((R - r - 2) 2 +(r + 3) 2 -R 2 ) / (2*(R - r - 2)*(r + 3))))*2 / 360°*2πr, and a = πr / n, unit mm, where R is the outer wall radius of the current steel pipe, r is the outer radius of the gasket, and n is a positive integer; height h of the gasket: h = δ max +20 and 30 ≤ h ≤ 50, unit mm, where δ max is the maximum value of the weld gap.

[0010] The beneficial effects of the present utility model are as follows: First, instead of using ceramic pads with relatively high costs, steel plate waste materials that are basically useless are adopted for production, which belongs to the reuse of waste materials, thereby reducing the welding cost. Second, the backing plate itself will not fall off, and the deposited metal has good adhesion, making it easy to weld and reducing the welding difficulty in various welding positions. Third, the requirement for the dimensional accuracy of the weld gap is relatively low, and it has good adaptability to the situation where it is difficult to make the assembly gap completely uniform in complex situations such as curved structures and pipe truss structures. Therefore, it has a higher and more stable welding qualification rate than ceramic pads, reducing the rework rate, thereby reducing the processing cost, welding auxiliary material cost, labor cost, and construction period impact caused by rework, and also reducing the increase in safety risks caused by rework and the environmental pollution caused by welding fumes. Fourth, the in-box welding is reduced, avoiding the adverse working environment and the safety risks such as asphyxiation during in-box welding. Fifth, when assembling and butting steel pipe members on-site, there is no need to enter the pipe to paste ceramic pads, which is convenient for welding. The present utility model is particularly applicable to the welding process occasions where the welding gap of cylindrical steel structure members is relatively large. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. is a schematic diagram of an embodiment in which the pad positioning device of the present utility model realizes positioning during welding.

[0012] Figure 2 is Figure 1 side view of.

[0013] Figure 3 FIG. is a schematic diagram of an embodiment of the pad positioning device of the present utility model.

[0014] Figure 4 is Figure 3 side view of.

[0015] In the figure, the markings are: the first steel member 1, the second steel member 2, the backing plate 3, the pad positioning device 4, the handle 41, the connecting rod 42, the magnetic support 44, the gap D, the sealing plate 43, and the neodymium iron boron permanent magnet sheet 45. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The present utility model will be further described below with reference to the drawings and embodiments.

[0017] As Figures 1 to 4Shown is a gasket positioning device 4 and an embodiment of the positional relationship between the gasket positioning device 4 and the first steel member 1, the second steel member 2, and the gasket plate 3 during welding. The gasket positioning device 4 first includes a connecting rod 42, and the connecting rod 42 can be a bent structure, which is convenient for construction workers to extend the magnetic support 44 at the other end of the connecting rod 42 to an easy-to-operate angle and position when holding the handle 41, facilitating subsequent welding. The bent state of the connecting rod 42 is flexibly adjusted according to the actual welding needs. The magnetic support 44 is an L-shaped bent structure, and the L-shaped bent structure includes a fixed side and a positioning side that are perpendicularly arranged, and the fixed side and the positioning side are welded with Q235B steel plates. The fixed side of the magnetic support 44 is Figure 3 the structure fixedly connected to one end of the connecting rod 42, and the positioning side of the magnetic support 44 is Figure 3 the structure perpendicular to the fixed side of the magnetic support 44, and the neodymium iron boron permanent magnet sheet 45 is arranged on the positioning side of the magnetic support 44. The neodymium iron boron permanent magnet sheet 45 can be pasted on the positioning side of the magnetic support 44 with silicone glue, and silicone glue is evenly applied to the exposed part of the neodymium iron boron permanent magnet sheet 45 to protect the permanent magnet sheet.

[0018] During actual use, the operator holds the handle 41 and arranges the positioning side of the magnetic support 44 at the bottom of the first steel member 1 and the second steel member 2 to be welded through the connecting rod 42. At this time, the neodymium iron boron permanent magnet sheet 45 adsorbs to the bottom of the first steel member 1 and the second steel member 2 to fix the magnetic support 44. Subsequently, an iron or steel gasket plate 3 is arranged at the bottom of the positioning side of the magnetic support 44, and the gasket plate 3 is also attracted by the magnetism of the neodymium iron boron permanent magnet sheet 45 and adheres closely, thereby realizing the locking of the relative positions between the first steel member 1, the second steel member 2, and the gasket plate 3. The gap D between the first steel member 1, the second steel member 2, and the gasket plate 3 is equal to the thickness of the positioning side of the magnetic support 44. Generally, the range of the gap D is 2 - 3 mm, preferably 2 mm. Subsequently, the gasket plate 3 is fixed to the first steel member 1 and the second steel member 2 by electric welding. Among them, the spot welding length 20 mm ≤ L1 ≤ 40 mm, the spacing 250 mm ≤ L ≤ 350 mm, and the fillet weld size 5 mm ≤ h f ≤ t + 2. The common spot welding length is 20 mm, the spacing is 300 mm, and the fillet weld size is 8 mm. The common sizes of the spot welding length, spacing, and fillet weld are the minimum sizes, and smaller sizes are likely to cause the gasket to be heated and deformed or fall off during the welding of the main weld. After fixing the gasket plate 3 in this way, the gasket plate 3 is bonded to the first steel member 1 and the second steel member 2 as a whole, which can avoid entering the box to paste the ceramic gasket again, greatly reducing the welding difficulty and improving the welding efficiency. After the gasket is welded and fixed, the gasket positioning device 4 is pulled out. At this time, there is a gap D between the gasket plate 3 and the first steel member 1 and the second steel member 2, and the gasket plate 3 no longer needs to be supported and will not fall off during subsequent welding, ensuring the welding quality.

[0019] The detailed welding process steps are as follows: a. According to the BIM model data and the requirements of the design drawings, check the dimensions of the components, the weld gap and root face dimensions between the first steel component 1 and the second steel component 2, and perform pre-treatment on the groove surface; when the component is a rolled welded steel pipe, check and correct the roundness of the rolled welded steel pipe. For steel pipes with relatively thin walls, add annular stiffeners; b. Fabricate the backing plate 3. The backing plate 3 is made of the same material as the first steel component 1 and the second steel component 2. After the backing plate 3 is cut according to the dimensions, clean the oxides and burrs on the backing plate 3 to ensure a flat surface; the backing plate 3 is processed from the leftover materials of the steel structure parts and is cut by laser cutting; c. Set the magnetic holder 44 at one end of the connecting rod 42 of the backing plate positioning device 4 between the backing plate 3, the first steel component 1 and the second steel component 2. The magnetic holder 44 is adsorbed on the bottoms of the first steel component 1 and the second steel component 2 through magnetic parts. The top surface of the backing plate 3 is closely attached to the magnetic holder 44, and the gap D between the top surface of the backing plate 3 and the bottoms of the first steel component 1 and the second steel component 2 is 2 - 3 mm; d. Fix the backing plate 3 to the first steel component 1 and the second steel component 2 by fillet weld spot welding, and then pull out the backing plate positioning device 4; e. Purge and clean the weld position area, and then complete the remaining welding process. The remaining welding process is to weld the main weld between the first steel component 1 and the second steel component 2 according to the welding process and parameters determined by the welding process qualification. Solid wire, flux-cored wire, gas shielded welding, submerged arc welding, manual welding, robotic welding, etc. can all be used for welding with corresponding process parameters.

[0020] As the core component of welding, the backing plate 3 needs to be adapted to the outer contour curved surfaces of the first steel component 1 and the second steel component 2. To better achieve the above matching and ensure the weld quality, the preferred dimensional parameters of the backing plate 3 are as follows: thickness t: 5 ≤ t ≤ T / 2, unit: mm, where T is the wall thickness of the butt-welded steel pipe; theoretical radius r' of the rolled backing plate: r' = R - T - 2, unit: mm, where R is the outer radius of the current steel pipe and T is the wall thickness of the butt-welded steel pipe, and the allowable deviation of the backing plate radius is [-5%, 0); arc length a of the backing plate: πr / 3 ≤ a ≤ (180° - arccos(((R - r - 2) 2 +(r + 3) 2 -R 2 )) / (2*(R - r - 2)*(r + 3))))*2 / 360°*2πr, and a = πr / n, unit: mm, where R is the outer radius of the current steel pipe, r is the outer radius of the backing plate, and n is a positive integer; height h of the backing plate: h = δ max +20 and 30 ≤ h ≤ 50, unit: mm, where δ max is the maximum value of the weld gap.

[0021] Embodiment

[0022] The following takes the on-site assembly welding of the steel pipe R800 arch rib of a landscape bridge as an example. The material is Q355C with a wall thickness of 20 mm for the butt joint seam.

[0023] 1. According to the requirements of the BIM model data and the detailed design drawings, check the dimensions of the first steel member 1 and the second steel member 2, as well as the weld gap and root face dimensions between the first steel member 1 and the second steel member 2. Confirm that the butt joints of the first steel member 1 and the second steel member 2 are well protected and not deformed during transportation and handling, and the docking marks are correct.

[0024] 2. Set up an on-site welding operation platform.

[0025] 3. The steel backing plate 3 is fabricated by the workshop and installed at the butt joints of the lower circular tube arch ribs of the first steel member 1 and the second steel member 2. For the steel backing plate 3 fabricated by the workshop, the leftover materials from the corners are preferably used for processing, and laser cutting is preferably used for blanking. The cut surface by laser cutting is flat and has less oxide. In this embodiment, the steel backing plate 3 is made of the same Q355C material as the base metal. The thickness of the steel backing plate 3 is 8 mm, the arc length is 348 mm, and the height is 30 mm. After the steel backing plate 3 is cut according to the controlled dimensions, the oxides, burrs, etc. are cleaned, and the surface is flat.

[0026] 4. Install the steel backing plate 3 by the workshop. Leave a gap D of 2 mm between the top surface of the steel backing plate 3 and the bottoms of the first steel member 1 and the second steel member 2. The specific way to leave the gap D is achieved by the aforementioned method of snapping the magnetic support 44. The center of the backing plate 3 is aligned with the center of the weld gap between the first steel member 1 and the second steel member 2. Neodymium iron boron permanent magnet sheets 45 are used to assist in fixing the backing plate 3 and determining the gap D. It is preferably installed using neodymium iron boron permanent magnet sheets 45. There is 1 neodymium iron boron permanent magnet sheet 45, which is fixed at the center position of the positioning edge of the magnetic support 44. Spot weld the edge of the steel backing plate 3 to the first steel member 1 and the second steel member 2 with fillet welds. The spot weld length is 20 mm, the spacing is 300 mm, and the weld leg size is 8 mm. Only weld one side of the steel backing plate 3 to the first steel member 1 and the second steel member 2, and the other side does not need to be welded and fixed. After welding and fixing the steel backing plate 3 in this way, it can prevent the operator from entering the box to paste the ceramic backing again, greatly improving the welding efficiency. After welding and fixing the backing plate, pull out the magnetic support 44 of the backing plate positioning device 4.

[0027] 5. Remove the protective film from the main weld position area between the first steel member 1 and the second steel member 2 on site.

[0028] 6. Weld the main weld according to the welding process and parameters evaluated by the welding process. Solid wire, flux-cored wire, gas shielded welding, submerged arc welding, manual welding, robotic welding, etc. can all be welded with corresponding process parameters.

[0029] This welding method is applicable to various welding positions. According to experimental tests, under the same welding conditions, the horizontal welding, vertical welding, and overhead welding positions are welded by the single-sided welding and double-sided forming process using this technical solution. The average qualified rate of the first-time welding is 98%, which is 11 percentage points higher than the average qualified rate of 87% in the conventional welding method. Moreover, the deviation of the qualified rate is smaller and the qualified rate is more stable. The increase in the qualified rate means the decrease in the rework rate. During rework, in addition to consuming the same welding auxiliary materials and working hours, it also increases the consumption of carbon rods, electricity, and labor costs for carbon arc air gouging. The increased carbon arc air gouging working hours are approximately 1 / 3 of the welding working hours. The decrease in the rework rate also reduces the environmental pollution caused by carbon arc air gouging and welding.

Claims

1. The backing positioning device for steel structure welding is characterized in that: The gasket positioning device (4) includes a connecting rod (42). One end of the connecting rod (42) is provided with a magnetic support (44), and a magnetic member is fixedly arranged on the magnetic support (44). The thickness of the magnetic support (44) is equal to the size of the gap (D) between the gasket plate (3) and the steel structure member. The other end of the connecting rod (42) is provided with a handle (41).

2. The backing positioning device for steel structure welding according to claim 1, characterized in that: The magnetic support (44) includes a fixed side and a positioning side. The fixed side and the positioning side are perpendicular to each other to form an L shape. The fixed side of the magnetic support (44) is fixedly arranged at the end of one end of the connecting rod (42), and the magnetic member is arranged on the positioning side of the magnetic support (44). The thickness of the positioning side of the magnetic support (44) is equal to the size of the gap (D) between the gasket plate (3) and the steel structure member.

3. The backing positioning device for steel structure welding according to claim 2, characterized in that: The magnetic member is a neodymium iron boron permanent magnet sheet (45).

4. The gasket positioning device for steel structure welding according to claim 2, characterized in that: The connecting rod (42) is of a bent structure, and the extending direction of the axis of the handle (41) is parallel to the extending direction of the positioning side of the magnetic support (44).

5. The gasket positioning device for steel structure welding according to any one of claims 1 to 4, characterized in that: The dimensional parameters of the gasket plate (3) are as follows: Thickness t: 5 ≤ t ≤ T / 2, unit: mm, where T is the wall thickness of the butt-welded steel pipe; The theoretical radius r' of the coiled gasket plate: r' = R - T - 2, unit: mm, where R is the outer wall radius of the current steel pipe and T is the wall thickness of the butt-welded steel pipe. The allowable deviation of the gasket plate radius is [-5%, 0); Arc length a of the backing plate: πr / 3 ≤ a ≤ (180° - arccos(((R - r - 2) 2 +(r + 3) 2 -R 2 ) / (2 * (R - r - 2) * (r + 3)))) * 2 / 360° * 2πr, and a = πr / n, unit: mm, R is the outer wall radius of the current steel pipe, r is the outer radius of the backing plate, n is a positive integer; Height h of the backing plate: h = δ max +20 and 30 ≤ h ≤ 50, unit: mm, where δ max is the maximum value of the weld gap.

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