Automatic welding method for assembly of orthotropic steel bridge deck steel box girder segments

Abstract

The invention discloses an orthotropic steel bridge deck slab steel box girder segment total assembly automatic welding method, and relates to the technical field of bridge construction in fixed buildings, and the method comprises the following steps: S1, positioning a central flat bottom plate unit, fixing the central flat bottom plate unit with a jig frame, then positioning and assembling two side flat bottom plate units, and finally assembling an inclined bottom plate unit to form a bottom plate unit; s2, a middle partition plate unit is assembled on the bottom plate unit, then a middle web plate unit is positioned, and finally the middle web plate unit, the middle partition plate unit and the bottom plate unit are welded; s3, the side partition plate units and the side web plate units are sequentially spliced on the inclined bottom plate units, and then welding is conducted; s4, the multiple steel bridge deck units are positioned and assembled in a crossed mode, and then welding is conducted; and S5, the steel bridge deck units, the middle partition plate units and the side partition plate units are welded and fixed, and then welding and fixing are conducted. The invention further discloses the technical problems that the labor intensity is high and the quality stability is poor during production of the orthotropic steel bridge deck steel box girder section.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction in fixed buildings, and particularly to an automatic welding method for the overall assembly of orthotropic steel bridge deck steel box girder segments. Background Art

[0002] The orthotropic steel bridge deck steel box girder is an efficient and economical bridge structure form. The closed cross-section of the steel box girder has excellent bending and torsion resistance performance. The orthotropic bridge deck forms an integral body through longitudinal and transverse stiffeners welded to the top plate and directly participates in the force of the main girder, greatly improving the local stiffness and overall stability of the bridge deck. The orthotropic steel bridge deck steel box girder is widely used in long-span suspension bridges, cable-stayed bridges and urban interchange projects, meeting the requirements of lightweight, high stiffness and multi-function, and is an optimal solution for modern bridge engineering.

[0003] At present, in the production of plate units of orthotropic steel bridge deck steel box girders, robot welding technology has been gradually adopted. For example, all-penetration welds of U-ribs on the bridge deck are automatically welded by an internal welding assembly machine and an external submerged arc special machine, and diaphragm units are automatically welded by a programmed teaching double-arm welding robot, etc. However, when the orthotropic steel bridge deck steel box girder segments are assembled integrally, due to space limitations and structural complexity, traditional gantry welding robots cannot be applied, and manual gas shielded welding or semi-automatic submerged arc welding is still mainly relied on, resulting in high manual labor intensity and poor quality stability. Therefore, improving the automation rate of the overall assembly welding of orthotropic steel bridge deck steel box girder segments, controlling the welding quality stability and ensuring the post-weld accuracy are key technologies in green bridge construction and have become major problems that need to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic welding method for the overall assembly of orthotropic steel bridge deck steel box girder segments, which solves the technical problems of high labor intensity and poor quality stability in the production of orthotropic steel bridge deck steel box girder segments in the prior art.

[0005] The embodiments of the present application disclose an automatic welding method for the overall assembly of orthotropic steel bridge deck steel box girder segments, including the following steps: S1: Locate the central flat bottom plate unit, fix it to the jig, then locate and assemble the flat bottom plate units on both sides, and finally assemble the inclined bottom plate unit to form the bottom plate unit; S2: Assemble the intermediate diaphragm unit on the bottom plate unit and temporarily support it, then locate the middle web unit, and finally weld the middle web unit, the middle diaphragm unit and the bottom plate unit; S3: Assemble the side diaphragm unit and the side web unit on the inclined bottom plate unit in sequence, and then weld between the side diaphragm unit, the side web unit and the inclined bottom plate unit; S4: Cross-position and assemble multiple steel bridge deck units, and then use a trackless crawling welding robot combined with a gas metal arc welding equipment to weld the longitudinal butt welds between the steel bridge deck units. S5: Weld and fix between the steel bridge deck unit, the middle diaphragm unit and the side diaphragm unit, then weld and fix between the middle web splice plate and the middle web unit, and finally complete the welding and fixing between the steel bridge deck and the side web unit.

[0006] This application improves the welding sequence and method, enhances the automation rate of the overall assembly welding of the orthotropic steel bridge deck steel box girder segment, controls the stability of its welding quality and ensures the post-welding accuracy.

[0007] On the basis of the above technical solutions, the embodiments of this application can also be improved as follows: Further, the specific content of step S1 is as follows: S101: Based on the central ground line and the transverse baseline at the end of the jig, position the flat bottom plate unit at the center position. After positioning, use elastic clamping plates to weld and fix it to the jig. S102: Based on the longitudinal baseline and the transverse baseline of the flat bottom plate unit at the center position, position and assemble the flat bottom plate units on both sides. S103: Based on the middle web ground line and the transverse baseline of the flat bottom plate unit, position the inclined bottom plate unit on the center side of the bridge. S104: Place heavy objects on the flat bottom plate unit for auxiliary pressing so that the gap between the bottom side of the flat bottom plate unit and the top side of the jig does not exceed 1 mm. S105: Use a trackless crawling welding robot and a gas metal arc welding equipment for combined welding, and symmetrically weld the longitudinal butt welds between the bottom plate units in the same direction and centered. The beneficial effect of this step is to ensure the welding quality by designing the welding sequence.

[0008] Further, the specific content of step S2 is as follows: S201: Based on the diaphragm position line and the central ground line on the bottom plate unit, assemble the diaphragm unit. S202: After assembly, use adjustable temporary diagonal braces to support the diaphragm unit, and there are at least two support points on each side of the diaphragm unit. S203: Based on the transverse baseline of the flat bottom plate unit and the inner and outer skin lines of the middle web, position the lower long side of the middle web unit, and then use the middle web ground line and the web center line on the outer surface of the upper flange of the middle web as the basis to position the upper long side of the middle web unit. S204: Use a vision - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the notch welds between the middle partition unit and the middle web unit, and between the middle partition unit and the flat bottom plate unit in a centered manner. Finally, use a drag - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the transverse longitudinal fillet welds between the middle web unit and the flat bottom plate unit in the same direction. The beneficial effect of this step is that through various benchmarks, the welding accuracy can be better guaranteed.

[0009] Further, the specific content of step S3 is as follows: S301: Assemble the side partition unit at the partition position on the inclined bottom plate unit; S302: Locate the lower edge of the side web based on the transverse baseline and the inner and outer skin lines of the side web on the inclined bottom plate unit, and then use the side measuring tower and the center of the side web to locate the upper edge of the side web unit; S303: Use a vision - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the notch welds between the side partition unit and the side web unit, and between the side partition unit and the flat bottom plate unit in a centered manner; S304: Use a drag - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the flat longitudinal fillet welds between the bottom plate and the side web in the same direction. The beneficial effect of this step is that through various benchmark positioning and in cooperation with the robot, the welding work can be better completed.

[0010] Further, the specific content of step S4 is as follows: S401: Locate the transverse positions of steel bridge deck units Ⅰ and Ⅱ based on the reference line of the middle measuring tower, and at the same time ensure the alignment accuracy of the suspension lines of the transverse baselines of steel bridge deck units Ⅰ and Ⅱ and the transverse baseline of the bottom plate unit, with the deviation ≤ 2 mm. Detect the position accuracy between the top plate and the partition unit in steel bridge deck units Ⅰ and Ⅱ, ensure that the misalignment at the butt joint is ≤ 0.5 mm, then spot - weld and fix, and assemble lead plates at both ends; S402: Locate the transverse positions of steel bridge deck units Ⅲ and Ⅳ based on the ground line of the middle web, and then perform spot - welding and fixing; S403: Locate the transverse positions of steel bridge deck units Ⅴ and Ⅵ based on the ground line of the side web, and then perform spot - welding and fixing; S404: Use a trackless crawling welding robot combined with a gas - shielded metal arc welding equipment to weld the longitudinal butt welds between steel bridge deck units Ⅰ and Ⅱ; S405: Locate the positions of steel bridge deck units Ⅶ and Ⅷ based on the combined reference line of steel bridge deck units Ⅰ and Ⅱ, then perform temporary fixing, and assemble lead plates at both ends; S406: Locate the positions of steel bridge deck units Ⅸ and Ⅹ based on the respective reference lines of steel bridge deck units Ⅲ and Ⅳ, then perform temporary fixing, and assemble lead plates at both ends; S407: Use a trackless crawling welding robot combined with a gas metal arc welding equipment to symmetrically weld the longitudinal butt welds between the remaining steel bridge deck units in the same direction and centered.

[0011] Further, the specific content of step S5 is as follows: S501: Use a drag teaching collaborative robot combined with a gas metal arc welding equipment to symmetrically weld the vertical butt welds and horizontal fillet welds between the diaphragm connecting plate of the steel bridge deck unit and the middle diaphragm unit and the side diaphragm unit in sequence; S502: Then use a trackless crawling welding robot combined with a gas metal arc welding equipment to symmetrically weld the horizontal longitudinal butt welds between the middle web connecting plate and the middle web unit in the same direction; S503: Use a trackless crawling welding robot combined with a gas metal arc welding equipment to symmetrically weld the horizontal longitudinal fillet welds between the steel bridge deck unit and the side web unit in the same direction.

[0012] Further, when automatically welding the longitudinal butt welds between the bottom plate units, adjust the welding torch of the trackless crawling welding robot to the front-mounted type; When automatically welding the longitudinal butt welds between the steel bridge deck units and the horizontal longitudinal fillet welds between the steel bridge deck unit and the side web unit, adjust the welding torch of the trackless crawling welding robot to the side-mounted type; The control program of the trackless crawling welding robot calls the automatic pulsed argon-rich gas shielded welding mode. The welding material for gas shielded welding is solid wire G49A3UC1S6, and the shielding gas is 80% Ar by volume and 20% CO 2 , the welding current is 230 - 250A, the arc voltage is 25 - 27V, the welding speed is 265 - 275mm / min, the dry elongation is 12 - 18mm, the gas flow rate is 25 - 30L / min, the arc oscillation method is zigzag, the oscillation width is 3 - 4mm, the oscillation frequency is 50 - 55 times / min, and the left and right stop durations are both 0.4s.

[0013] Further, when automatically welding the notch welds between the diaphragm unit and the web unit and the bottom plate unit, the control program of the drag teaching collaborative robot calls the automatic pulsed CO 2 gas shielded welding mode. The welding material for gas shielded welding is flux-cored wire T492T1-1C1AUH5, the welding current is 165 - 185A, the arc voltage is 24 - 26V, the welding speed is 135 - 155mm / min, the dry elongation is 12 - 18mm, the gas flow rate is 15 - 20L / min, the arc oscillation method is triangular, the oscillation width is 4 - 6mm, the oscillation frequency is 45 - 50 times / min, and the left and right stops are both 0.6s.

[0014] Further, when automatically welding the fillet welds between the web unit and the bottom plate unit, and between the transverse diaphragm connecting plate and the diaphragm unit, the drag teaching collaborative robot is called to use the automatic pulsed CO 2 gas shielded welding mode. The welding material for gas shielded welding is flux-cored wire T492T1-1C1AUH5. The welding current is 230 - 250A, the arc voltage is 23 - 25V, the welding speed is 255 - 275mm / min, the dry elongation is 12 - 18mm, the gas flow rate is 15 - 20L / min, the swing arc mode is sine-shaped, the swing width is 3 - 5mm, and the swing frequency is 85 - 90 times / min. The left and right stops are both 0.5s.

[0015] Further, when automatically welding the transverse longitudinal butt welds between the middle web connecting plate and the middle web unit, the control program of the trackless crawling welding robot calls the automatic pulsed argon-rich gas shielded welding mode. The welding torch angle is tilted backward by 6 - 8°. The welding material is solid wire G49A3UC1S6. The shielding gas is 80% Ar and 20% CO2 by volume. The welding current is 210 - 230A, the arc voltage is 22 - 24V, the welding speed is 230 - 250mm / min, the dry elongation is 12 - 18mm, the gas flow rate is 25 - 30L / min, the swing arc mode is zigzag, the swing width is 2 - 3mm, and the swing frequency is 55 - 60 times / min. The left and right stops are both 0.5s.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The present invention discloses an automatic welding method for the overall assembly of orthotropic steel bridge deck steel box girder segments, and proposes a complete set of automatic welding solutions for the overall assembly of orthotropic steel bridge deck steel box girder segments. According to a specific welding sequence, a device group including FANUC CRX-5IA vision teaching collaborative robot, FANUC CRX-5IA drag teaching collaborative robot, and trackless crawling welding robot (Boqing BOT-WTA20-322) is adopted, combined with a gas metal arc welding equipment, and cooperating with welding tooling such as a transverse hydraulic slide rail and an electric drive lifting device, realizing the automatic high-quality welding of the overall assembly of orthotropic steel bridge deck steel box girder segments. It solves the production problem that in the current overall assembly process, traditional gantry welding robots cannot be applied, and manual gas shielded welding or semi-automatic submerged arc welding is still mainly relied on, resulting in high labor intensity of workers and poor quality stability.

[0017] 2. The automatic welding method disclosed in the present application not only significantly improves the welding construction efficiency of the overall assembly of orthotropic steel bridge deck steel box girder segments and greatly shortens the manufacturing period, but also effectively ensures the welding quality stability and the overall post-welding accuracy, strongly promoting the application of automatic welding technology in the manufacture of steel bridges and accelerating the transformation of bridge construction technology towards green and low-carbon. Description of the Drawings

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of the overall structure of the orthotropic steel bridge deck steel box girder segment described in the specific embodiment of the present invention; Figure 2 It is a schematic diagram of the overall assembly welding process of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 3 It is a schematic diagram of the automatic welding sequence of the orthotropic steel bridge deck steel box girder segment in the present invention. In the figure, the digital serial numbers ①-㉑ represent the welding sequence, and the arrow direction is the welding direction; Figure 4 It is a schematic diagram of the automatic welding of the longitudinal butt weld between the bottom plates of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 5 It is a schematic diagram of the automatic welding of the notch weld between the diaphragm and the bottom plate of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 6 It is a schematic diagram of the automatic welding of the weld between the web and the bottom plate of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 7 It is a schematic diagram of the automatic welding of the weld between the transverse diaphragm connecting plate and the diaphragm of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 8 It is a schematic diagram of the automatic welding of the weld between the middle web connecting plate and the middle web of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 9 It is a schematic diagram of the automatic welding of the longitudinal butt weld between the steel bridge decks of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 10 It is a schematic diagram of the welding requirements at the cross-shaped ring opening of the steel bridge deck and the bottom plate of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 11 It is a schematic diagram of the automatic welding of the weld between the steel bridge deck and the side web of the orthotropic steel bridge deck steel box girder segment in the present invention; Figure 12 It is a physical diagram of the laser scanning longitudinal butt weld welding groove before welding by the trackless crawling welding robot in the present invention; Figure 13It is a physical drawing of the automatic welding of the simulated test piece of the longitudinal butt weld of the steel bridge deck in the overall assembly of the steel box girder segment of the orthotropic steel bridge deck in the present invention; Figure 14 It is a physical drawing of the automatic welding of the simulated test piece of the transverse longitudinal butt weld between the middle web connecting plate and the middle web in the overall assembly of the steel box girder segment of the orthotropic steel bridge deck in the present invention.

[0020] Figure 15 It is a schematic structural diagram of the steel bridge deck unit in the overall assembly of the steel box girder segment of the orthotropic steel bridge deck in the present invention.

[0021] Reference signs: 1 - Steel box girder segment of orthotropic steel bridge deck, 2 - Bottom plate unit, 3 - Middle diaphragm unit, 4 - Middle web unit, 5 - Side diaphragm unit, 6 - Side web unit, 7 - Steel bridge deck unit, 8 - Diaphragm connecting plate, 9 - Middle web connecting plate, 10 - Trackless crawling welding robot, 11 - Vision teaching collaborative robot, 12 - Transverse hydraulic slide rail, 13 - Drag teaching collaborative robot, 14 - Electric drive lifting device; 701 - Steel bridge deck unit Ⅰ; 702 - Steel bridge deck unit Ⅱ; 703 - Steel bridge deck unit Ⅲ; 704 - Steel bridge deck unit Ⅳ; 705 - Steel bridge deck unit Ⅴ; 706 - Steel bridge deck unit Ⅵ; 707 - Steel bridge deck unit Ⅶ; 708 - Steel bridge deck unit Ⅷ; 709 - Steel bridge deck unit Ⅸ; 710 - Steel bridge deck unit Ⅹ. Detailed implementation manners

[0022] Next, embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention. It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0023] In this application, unless otherwise clearly defined and limited, terms such as "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the accompanying drawings of the specification and the specific implementation manners.

[0025] Example 1: This application discloses an automatic welding method for longitudinal assembly welding of orthotropic steel bridge deck steel box girder segments. According to a specific welding sequence, an automatic welding operation for the longitudinal butt weld of the steel bridge deck unit and the bottom plate unit is completed by using a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas metal arc welding equipment. The automatic welding operation for the notch weld between the diaphragm unit (including the side diaphragm unit and the middle diaphragm unit) and the bottom plate unit is completed by using a FANUC CRX-5IA vision teaching collaborative robot combined with a gas metal arc welding equipment. The automatic welding operation for the fillet weld between the web unit (including the side web unit and the middle web unit) and the bottom plate unit is completed by using a FANUC CRX-5IA drag teaching collaborative robot combined with a gas metal arc welding equipment. The automatic welding operation for the longitudinal fillet weld between the large steel bridge deck yard and the side web unit is completed by using a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas metal arc welding equipment. The automatic welding operation for the connecting weld between the transverse diaphragm connecting plate and the diaphragm unit is completed by using a FANUC CRX-5IA drag teaching collaborative robot combined with a gas metal arc welding equipment.

[0026] S1: Locate the central flat bottom plate unit, fix it to the jig, then locate and assemble the flat bottom plate units on both sides, and finally assemble the inclined bottom plate unit to form the bottom plate unit; the specific content of step S1 is as follows: S101: Based on the central ground line and the transverse baseline at the end of the jig, it is necessary to ensure that the longitudinal and transverse baselines are strictly aligned. Locate the flat bottom plate unit at the central position (the flat bottom plate unit of this round of total assembly segment). After positioning, weld and fix it to the jig with elastic clamping plates. This jig is the general assembly jig. S102: Based on the longitudinal baseline and the transverse baseline of the flat bottom plate unit at the located central position, use a tape measure to re-locate and assemble the flat bottom plate units on both sides. S103: Based on the middle web ground line and the transverse baseline of the flat bottom plate unit, locate the inclined bottom plate unit on the bridge center side. S104: Place heavy objects on the flat bottom plate unit for auxiliary pressing so that the gap between the bottom side of the flat bottom plate unit and the top side of the jig does not exceed 1 mm, which can ensure that the bottom side of the flat bottom plate unit is in close contact with the supporting surface of the jig. S105: Use a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas metal arc welding equipment for combined welding, and perform symmetric welding in the same direction and centered on the longitudinal butt weld between the bottom plate units. S2: Assemble the middle diaphragm unit on the bottom plate unit and provide temporary support for it, then locate the middle web unit, and finally weld the middle web unit, the middle diaphragm unit and the bottom plate unit; among them, the specific content of step S2 is as follows: S201: Based on the partition position line and the central ground sample line on the bottom plate unit, assemble the partition unit. During assembly, pay attention to the partition spacing, and evenly distribute the transverse bridge deviation on both sides; S202: After assembly, use adjustable temporary diagonal struts to support the partition unit. There should be at least two support points on each side of the partition unit. At the same time, weld single-sided K8 welds at both ends, with a length of not less than 50 mm; S203: Based on the transverse baseline of the flat bottom plate unit and the inner and outer skin lines of the middle web, position the lower long side of the middle web unit, and then use the middle web ground sample line and the web center line on the outer surface of the upper flange of the middle web as a reference to position the upper long side of the middle web unit; S204: Use a vision - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the groove welds between the middle partition unit and the middle web unit and the flat bottom plate unit in a centered manner. Finally, use a drag - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the transverse longitudinal fillet welds between the middle web unit and the flat bottom plate unit in the same direction; S3: Sequentially assemble the side partition units and side web units on the inclined bottom plate unit, and then perform welding between the side partition units, side web units, and the inclined bottom plate unit. Among them, the specific content of step S3 is as follows: S301: Assemble the side partition units based on the partition position on the inclined bottom plate unit. During assembly, pay attention to the verticality and spacing of the side partition; S302: Based on the transverse baseline on the inclined bottom plate unit and the inner and outer skin lines of the side web, position the lower side of the side web, and then use the side measuring tower and the center of the side web to position the upper side of the side web unit; S303: Use a vision - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the groove welds between the side partition units and the side web units and the bottom plate unit in a centered manner; S304: Use a drag - teaching collaborative robot combined with a gas - shielded metal arc welding equipment to symmetrically weld the flat longitudinal fillet welds between the bottom plate unit and the side web unit in the same direction; S4: Cross - position and assemble multiple steel bridge deck units, and then use a trackless crawling welding robot combined with a gas - shielded metal arc welding equipment to weld the longitudinal butt welds between the steel bridge deck units. Among them, the steel bridge deck units include transverse diaphragm connecting plates, top plate units, and middle web connecting plates; The specific content of the said step S4 is as follows: S401: Based on the reference line of the middle measuring tower, position the transverse positions of the steel bridge deck units Ⅰ and Ⅱ. At the same time, ensure the alignment accuracy of the hanging lines of the transverse baselines of the steel bridge deck units Ⅰ and Ⅱ and the transverse baseline of the bottom plate unit, with a deviation ≤ 2 mm. Detect the position accuracy between the top plate units in the steel bridge deck units Ⅰ and Ⅱ and the partition units (including side partition units and middle partition units), ensure that the misalignment at the butt joint is ≤ 0.5 mm, then spot - weld and fix, and assemble lead plates at both ends; S402: Locate the transverse positions of steel bridge deck units Ⅲ and Ⅳ according to the ground line of the middle web, and then carry out tack welding. When carrying out tack welding, it is also necessary to ensure that the alignment accuracy of the transverse baseline, the spacing of the longitudinal baselines, the offset amount at the butt joint of the connecting plate, etc. meet the process requirements. For specific requirements, refer to step S401; S403: Locate the transverse positions of steel bridge deck units Ⅴ and Ⅵ according to the ground line of the side web, and then carry out tack welding. When carrying out tack welding, it is also necessary to ensure that the alignment accuracy of the transverse baseline, the spacing of the longitudinal baselines, the offset amount at the butt joint of the connecting plate, etc. meet the process requirements. For specific requirements, refer to step S401; S404: Use a trackless crawling welding robot combined with a gas shielded metal arc welding equipment to weld the longitudinal butt welds between steel bridge deck units Ⅰ and Ⅱ; S405: Locate the positions of steel bridge deck units Ⅶ and Ⅷ according to the joint reference line of steel bridge deck units Ⅰ and Ⅱ, and then carry out temporary fixing, and assemble lead plates at both ends. When fixing, it is also necessary to ensure that the alignment accuracy of the transverse baseline, the spacing of the longitudinal baselines, the offset amount at the butt joint of the connecting plate, etc. meet the process requirements. For specific requirements, refer to step S401. When carrying out temporary fixing, it is temporarily fixed with the adjacent top plate unit; S406: Locate the positions of steel bridge deck units Ⅸ and Ⅹ according to the respective reference lines of steel bridge deck units Ⅲ and Ⅳ, and then carry out temporary fixing, and assemble lead plates at both ends; when fixing, it is also necessary to ensure that the alignment accuracy of the transverse baseline, the spacing of the longitudinal baselines, the offset amount at the butt joint of the connecting plate, etc. meet the process requirements. For specific requirements, refer to step S401. When carrying out temporary fixing, it is temporarily fixed with the adjacent top plate unit; S407: Use a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas shielded metal arc welding equipment to symmetrically weld the remaining longitudinal butt welds between steel bridge deck units in the same direction and centered; S5: Carry out welding and fixing between the steel bridge deck unit and the middle diaphragm unit and the side diaphragm unit, then carry out welding and fixing between the middle web connecting plate and the middle web unit, and finally complete the welding and fixing between the steel bridge deck and the side web unit; among them, the specific content of step S5 is as follows: S501: Use a drag teaching collaborative robot combined with a gas shielded metal arc welding equipment to symmetrically weld the vertical butt welds and horizontal fillet welds between the transverse diaphragm connecting plate of the steel bridge deck unit and the middle diaphragm unit and the side diaphragm unit in sequence; S502: Then use a trackless crawling welding robot combined with a gas shielded metal arc welding equipment to symmetrically weld the horizontal longitudinal butt welds between the middle web connecting plate and the middle web unit in the same direction; S503: Use a trackless crawling welding robot combined with a gas shielded metal arc welding equipment to symmetrically weld the horizontal longitudinal fillet welds between the steel bridge deck unit and the side web unit in the same direction.

[0027] To better complete the automated welding of the overall assembly of beam segments, this application designs the corresponding steps. Among them, when automatically welding the longitudinal butt welds between the bottom plate units, the welding torch of the trackless crawling welding robot is adjusted to a front-mounted type; among them, when automatically welding the longitudinal butt welds between the steel bridge deck units and the flat longitudinal fillet welds between the steel bridge deck units and the side web units, the welding torch of the trackless crawling welding robot is adjusted to a side-mounted type; It does not require manual programming, uses laser scanning to identify the welding groove, and automatically plans the welding path. The robot control program calls the automatic pulsed argon-rich gas shielded welding mode. The welding material for gas shielded welding is solid wire G49A3UC1S6 (φ1.2mm), the shielding gas is 80% Ar by volume and 20% CO2 by volume, the welding current is 230 - 250A, the arc voltage is 25 - 27V, the welding speed is 265 - 275mm / min, the dry elongation is 12 - 18mm, the gas flow rate is 25 - 30L / min, the arc oscillation method is zigzag, the oscillation width is 3 - 4mm, the oscillation frequency is 50 - 55 times / min, and the left and right stop durations are both 0.4s.

[0028] Among them, the trackless crawling welding robot (Boqing BOT-WTA20-322) does not require manual programming, uses laser scanning to identify the welding groove, and automatically plans the welding path. The robot control program calls the automatic pulsed argon-rich gas shielded welding mode. The welding material for gas shielded welding is solid wire G49A3UC1S6 (φ1.2mm), the shielding gas is 80% Ar by volume and 20% CO 2 , the welding current is 230A or 240A or 250A (range 230A - 250A), the arc voltage is 25V or 26V or 27V (range 25 - 27V), the welding speed is 265mm / min or 270mm / min or 275mm / min (range 265 - 275mm / min), the dry elongation is 12mm or 15mm or 18mm (range 12 - 18mm), the gas flow rate is 25L / min or 28L / min or 30L / min (range 25 - 30L / min), the arc oscillation method is zigzag, the oscillation width is 3mm or 4mm or 3.5mm (range 3 - 4mm), the oscillation frequency is 50 times / min or 52 times / min or 55 times / min (range 50 - 55 times / min) 50 - 55 times / min, and the left and right stop durations are both 0.4s.

[0029] Among them, when the partition unit (including side partitions and middle partitions) is automatically welded to the web unit (including middle web units and side web units) and the bottom plate unit by groove welds, the collaborative robot is equipped with a vision teaching pendant. The real-time images of the workpiece and the weld seam are captured by the camera, and the welding path is automatically generated by combining algorithms. Compared with conventional drag teaching and laser teaching, vision teaching is more suitable for multi-segment curved welds. For complex paths, there is no need for multiple adjustments, and the teaching time is shorter. The control program of this robot calls the automatic pulse CO 2 gas shielded welding mode. The welding material for gas shielded welding is flux-cored wire T492T1-1C1AUH5 (φ1.2mm). The welding current is 165A or 175A or 185A (range: 165A - 185A), the arc voltage is 24V or 25V or 26V (range: 24 - 26V), the welding speed is 135mm / min or 145mm / min or 155mm / min (range: 135 - 155mm / min), the dry elongation is 12mm or 15mm or 18mm (range: 12 - 18mm), the gas flow rate is 15L / min or 18L / min or 20L / min (range: 15 - 20L / min), the weaving mode is triangular, the weaving width is 4mm or 5mm or 6mm (range: 4 - 6mm), the weaving frequency is 45 times / min or 48 times / min or 50 times / min (range: 45 - 50 times / min), and the left and right stops are both 0.6s.

[0030] Among them, when the partition unit is automatically welded to the web unit and the bottom plate by groove welds, to improve the visual recognition accuracy, a welding anti-spatter agent can be sprayed and dyed on the area to be welded to avoid the reflection of the metallic luster after grinding and rust removal in the area to be welded, which affects the camera's capture of the real-time images of the workpiece and the weld seam. When the partition unit is automatically welded to the bottom plate unit by groove welds, after the welding path of the first groove is planned by vision teaching, the teaching process can be skipped for the welding of subsequent other grooves. At the same time, a transverse hydraulic slide rail is provided under the collaborative robot. After the welding of the previous groove is completed, it can automatically slide to the center line position of the next groove to achieve continuous automatic welding of multiple grooves, significantly improving production efficiency.

[0031] Among them, when the web unit is automatically welded to the bottom plate unit and the fillet welds between the transverse diaphragm connecting plate and the partition are automatically welded, the collaborative robot uses the drag teaching function. The operator can directly drag the robot arm to program the welding path without using a traditional teaching pendant or writing code. It is more suitable for long straight welds and realizes fast and intuitive path planning. The robot control program calls the automatic pulse CO 2Gas shielded welding mode. For the flux-cored wire T492T1-1C1AUH5 (φ1.2mm) used in gas shielded welding, the welding current is 230A or 240A or 250A (range: 230 - 250A), the arc voltage is 23V or 24V or 25V (range: 23 - 25V), the welding speed is 255mm / min or 265mm / min or 275mm / min (range: 255 - 275mm / min), the dry elongation is 12mm or 16mm or 18mm (range: 12 - 18mm), the gas flow rate is 15L / min or 18L / min or 20L / min (range: 15 - 20L / min), the swing arc mode is sine-shaped, the swing width is 3mm or 4mm or 5mm (range: 3 - 5mm), the swing frequency is 85 times / min or 88 times / min or 90 times / min, and the left and right stops are both 0.5s.

[0032] Among them, when the horizontal fillet weld between the transverse diaphragm connecting plate and the diaphragm is automatically welded, an electric drive lifting device is provided under the collaborative robot. The drag teaching collaborative robot can match the welding height according to the position of the transverse diaphragm connecting plate, avoiding high-altitude operation by personnel and significantly improving the construction safety factor.

[0033] Among them, when the horizontal longitudinal butt weld between the middle web connecting plate and the middle web is automatically welded, the trackless crawling welding robot control program calls the automatic pulsed argon-rich gas shielded welding mode. The welding torch angle is tilted backward by 6 - 8°. The welding material is solid wire G49A3UC1S6 (φ1.2mm). The shielding gas is 80% Ar by volume and 20% CO2 by volume. The welding current is 210A or 220A or 230A (range: 210 - 230A), the arc voltage is 22V or 23V or 24V (range: 22 - 24V), the welding speed is 230mm / min or 240mm / min or 250mm / min (range: 230 - 250mm / min), the dry elongation is 12mm or 16mm or 18mm (range: 12 - 18mm), the gas flow rate is 25L / min or 28L / min or 30L / min (range: 25 - 30L / min), the swing arc mode is zigzag, the swing width is 2mm or 3mm (range: 2 - 3mm), the swing frequency is 55 times / min or 58 times / min or 60 times / min (range: 55 - 60 times / min), and the left and right stops are both 0.5s.

[0034] Among them, when welding the longitudinal butt welds of the steel bridge deck unit and the bottom plate unit, the arc shall be struck at the position where the lead plate is installed and extinguished at the position of the quenching plate. It is not allowed to strike or extinguish the arc within 300 mm of the beam end during the process, and continuous welding shall be carried out through the bridging lead plate at the cross weld. If there is an arc extinguishing point during the welding process, a 1:5 transition slope shall be ground at the arc extinguishing point and welding shall continue after lapping 50 mm.

[0035] A further description is made for this application: This application discloses an orthotropic steel bridge deck steel box girder segment, including a bottom plate unit, a middle partition unit, a middle web unit, a side partition unit, a side web unit, a side steel bridge deck unit, and a steel bridge deck unit; the steel bridge deck unit includes a diaphragm connecting plate, a top plate unit, and a middle web connecting plate. When the orthotropic steel bridge deck steel box girder segment is assembled integrally, all adjacent plate units are connected by welding. When traditional intensive manual welding is used, not only is the labor intensity high and the construction efficiency low, but also the welding quality stability and the post-weld accuracy are poor.

[0036] For the aforementioned orthotropic steel bridge deck steel box girder segment, this application also discloses an automated welding method. According to a specific welding sequence, an automated welding operation of the longitudinal butt welds of the steel bridge deck unit and the bottom plate unit is completed by using a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas metal arc welding equipment. An automated welding operation of the slot weld between the partition unit and the bottom plate unit is completed by using a FANUC CRX-5IA vision teaching collaborative robot combined with a gas metal arc welding equipment. An automated welding operation of the fillet weld between the web unit and the bottom plate unit is completed by using a FANUC CRX-5IA drag teaching collaborative robot combined with a gas metal arc welding equipment. An automated welding operation of the longitudinal fillet weld between the steel bridge deck unit and the side web is completed by using a trackless crawling welding robot (Boqing BOT-WTA20-322) combined with a gas metal arc welding equipment. An automated welding operation of the connecting weld between the diaphragm connecting plate and the partition unit is completed by using a FANUC CRX-5IA drag teaching collaborative robot combined with a gas metal arc welding equipment.

[0037] A description is made for the trackless crawling welding robot in this application. Before welding, the welding groove of the trackless crawling welding robot needs to be scanned and identified by laser. After scanning, it pre-walks 1.5 meters without striking an arc to determine the crawling state of the welding robot. If the walking deviation in the weld width direction exceeds 3 mm, the permanent magnet knob at the bottom of the robot needs to be adjusted. After the pre-walking is qualified, welding begins.

[0038] Among them, collaborative robots (including drag-teaching collaborative robots and vision-teaching collaborative robots) and trackless crawling welding robots need to store welding parameter packages in the teach pendant. During the construction process, they can be directly called as a complete set, ensuring the accuracy of parameter selection while avoiding repeated input.

[0039] The collaborative robot shall be equipped with an arc tracking function. When the welding groove is irregularly opened, the swing arc path of the welding torch can be changed through parameter variation to achieve real-time deviation correction. The trackless crawling welding robot shall be equipped with a laser deviation correction function. When the welding groove is irregularly opened, the groove contour can be identified by laser, and the traveling path of the vehicle body can be changed to achieve real-time deviation correction, avoiding welding deviation and ensuring the weld fusion quality.

[0040] Among them, the collaborative robot and the trackless crawling welding robot can perform data interaction with the digital production line system through the 5G network, automatically receive and feedback the total segment assembly manufacturing information, and realize the real-time progress monitoring of the orthotropic steel bridge deck steel box girder segment total assembly.

[0041] The bottom plate unit, middle partition unit, middle web unit, side partition unit, side web unit, side steel bridge deck unit, and steel bridge deck unit in this application can be existing assemblies, which will not be elaborated here.

[0042] In the description of the present invention, a large number of specific details are set forth. However, it is understood that the embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered within the scope of the claims and the description of the present invention.

Claims

1. An automated welding method for the overall assembly of orthotropic steel bridge deck steel box girder segments, characterized in that: The following steps are involved: S1: Position the central flat floor unit and fix it to the tire frame, then position and assemble the flat floor units on both sides, and finally assemble the inclined floor unit to form a floor unit; S2: assembling the middle partition unit on the bottom plate unit and temporarily supporting it, then positioning the middle web unit, and finally welding the middle web unit, the middle partition unit and the bottom plate unit; S3: assembling the side diaphragm unit and the side web unit on the inclined bottom plate unit in sequence, and then welding the side diaphragm unit, the side web unit and the inclined bottom plate unit; S4: Assemble multiple steel bridge deck units by cross positioning, and then use a trackless crawling welding robot combined with a consumable gas shielded welding device to weld the longitudinal butt welds between the steel bridge deck units; S5: Welding and fixing are performed between the steel bridge deck unit and the middle diaphragm unit and the side diaphragm unit, and then welding and fixing are performed between the middle web plate connecting plate and the middle web unit, and finally welding and fixing are completed between the steel bridge deck and the side web unit.

2. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 1 is characterized in that: The specific content of step S1 is as follows: S101: Using the center ground sample line and the tire frame end transverse baseline as reference, locate the flat bottom plate unit at the center position, and after the positioning is completed, weld and fix it to the tire frame with an elastic plate; S102: Using the longitudinal baseline and the transverse baseline of the flat bottom plate unit at the center as reference, positioning and assembling the flat bottom plate units at both sides; S103: Using the mid-web ground sample line and the horizontal baseline of the flat bottom plate unit as reference, locate the inclined bottom plate unit on the center side of the bridge; S104: placing a heavy object on the flat bottom plate unit to assist in pressing, so that the gap between the bottom side of the flat bottom plate unit and the top side of the tire frame does not exceed 1 mm; S105: Use trackless crawling welding robot and consumable gas shielded welding equipment for joint welding, and weld the longitudinal butt welds between the base plate units symmetrically in the same direction.

3. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 2 is characterized in that: The specific content of step S2 is as follows: S201: Assembling the partition unit based on the partition position line and the center ground sample line on the bottom plate unit; S202: After the assembly is completed, the partition unit is supported by using an adjustable temporary diagonal brace, and each side of the partition unit has at least two points of support; S203: Using the horizontal baseline of the flat bottom plate unit and the inner and outer skin lines of the middle web plate as references, locate the lower long side of the middle web plate unit, and then use the middle web plate ground sample line and the web center line on the outer surface of the flange of the middle web plate as references to locate the upper long side of the middle web plate unit; S204: A visual teaching collaborative robot is used in combination with a consumable electrode gas shielded welding device to symmetrically weld the notch welds between the middle partition unit and the middle web unit and the flat bottom plate unit. Finally, a dragging teaching collaborative robot is used in combination with a consumable electrode gas shielded welding device to symmetrically weld the horizontal longitudinal fillet welds between the middle web unit and the flat bottom plate unit in the same direction.

4. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 3 is characterized in that: The specific content of step S3 is as follows: S301: Assembling the side partition plate unit at the partition plate position on the inclined bottom plate unit; S302: Locate the lower edge of the side web plate based on the horizontal baseline on the inclined bottom plate unit and the inner and outer skin lines of the side web plate, and locate the upper edge of the side web plate unit using the side measurement tower and the center of the side web plate; S303: Use visual teaching collaborative robots in conjunction with consumable gas shielded arc welding equipment to symmetrically weld the notch welds between the side partition plate unit and the side web plate unit, and the flat bottom plate unit; S304: A dragging teaching collaborative robot is used in conjunction with a consumable gas shielded welding device to weld the horizontal longitudinal fillet weld between the bottom plate and the side web symmetrically in the same direction.

5. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 4 is characterized in that: The specific content of step S4 is as follows: S401: Use the middle measuring tower reference line to locate the transverse position of steel bridge deck units I and II, and ensure the alignment accuracy of the suspension lines between the transverse baselines of steel bridge deck units I and II and the transverse baselines of the bottom plate units, with a deviation of ≤2mm. Detect the position accuracy of the top plate and diaphragm units in steel bridge deck units I and II, and ensure that the misalignment at the joint between the two is ≤0.5mm, then spot weld and fix them, and assemble the guide plates at both ends; S402: Locate the transverse positions of steel bridge deck units III and IV using the mid-web ground sample line, and then perform spot welding to fix them; S403: Locate the transverse positions of the steel bridge deck units V and VI using the side web ground sample line, and then perform spot welding to fix them; S404: A trackless crawling welding robot is used in conjunction with a consumable gas shielded welding device to weld the longitudinal butt weld between steel bridge deck units I and II; S405: Locate the positions of steel bridge deck units VII and VIII based on the joint reference line of steel bridge deck units I and II, then perform the horse fastening and assemble the guide plates at both ends; S406: locate the positions of the steel bridge deck units IX and X based on the respective reference lines of the steel bridge deck units III and IV, then perform the horse fastening, and assemble the guide plates at both ends; S407: A trackless guided crawling welding robot is used in conjunction with a consumable gas shielded welding device to symmetrically weld the longitudinal butt welds between the remaining steel bridge deck units in the same direction.

6. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 5 is characterized in that: The specific content of step S5 is as follows: S501: Use the dragging teaching collaborative robot in conjunction with the consumable gas shielded welding equipment to symmetrically weld the vertical butt welds and horizontal fillet welds of the transverse diaphragm joint plate of the steel bridge deck unit and the middle diaphragm unit and the side diaphragm unit in sequence; S502: Then, a trackless guided crawling welding robot is used in conjunction with a consumable gas shielded welding device to symmetrically weld the horizontal longitudinal butt weld between the middle web plate connecting plate and the middle web plate unit in the same direction; S503: A trackless guided crawling welding robot is used in conjunction with a consumable gas shielded welding device to weld the horizontal longitudinal fillet welds between the steel bridge deck unit and the side web unit symmetrically in the same direction.

7. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 6 is characterized in that: When the longitudinal butt welds between the base plate units are automatically welded, the welding gun of the trackless crawling welding robot is adjusted to a front-mounted type; When the longitudinal butt welds between the steel bridge deck units and the parallel longitudinal fillet welds between the steel bridge deck units and the side webs are automatically welded, the welding gun of the trackless crawling welding robot is adjusted to a side-mounted type; The control program of the trackless guided crawling welding robot calls the automatic pulse argon-rich gas shielded welding mode. The gas shielded welding material is solid welding wire G49A3UC1S6, the shielding gas is 80% Ar by volume and 20% CO2 by volume, the welding current is 230-250A, the arc voltage is 25-27V, the welding speed is 265-275mm / min, the dry extension is 12-18mm, the gas flow rate is 25-30L / min, the arc swing mode is sawtooth, the swing width is 3-4mm, the swing frequency is 50-55 times / min, and the left and right stop times are both 0.4s.

8. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 7 is characterized in that: When the notch welds between the partition unit and the web unit and the bottom plate unit are automatically welded, the teaching collaborative robot control program is dragged to call the automatic pulse CO2 gas shielded welding mode. The gas shielded welding material is the flux-cored wire T492T1-1C1AUH5. The welding current is 165-185A, the arc voltage is 24-26V, the welding speed is 135-155mm / min, the dry extension is 12-18mm, the gas flow rate is 15-20L / min, the arc swing mode is triangular, the swing width is 4-6mm, the swing frequency is 45-50 times / min, and the left and right stops are both 0.6s.

9. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 7, characterized in that: When automatically welding the fillet welds between the web unit and the bottom plate unit, and between the cross plate connecting plate and the partition unit, the teaching collaborative robot is dragged to call the automatic pulse CO2 gas shielded welding mode. The gas shielded welding material is the flux-cored wire T492T1-1C1AUH5. The welding current is 230-250A, the arc voltage is 23-25V, the welding speed is 255-275mm / min, the dry extension is 12-18mm, the gas flow rate is 15-20L / min, the arc swing mode is sinusoidal, the swing width is 3-5mm, the swing frequency is 85-90 times / min, and the left and right stops are both 0.5s.

10. The automated welding method for orthotropic steel bridge deck steel box girder segment assembly according to claim 9, characterized in that: When the horizontal longitudinal butt weld between the middle web connecting plate and the middle web unit is automatically welded, the control program of the trackless crawling welding robot calls the automatic pulse argon-rich gas shielded welding mode, the welding gun is tilted back by 6-8°, the welding material is solid welding wire G49A3UC1S6, the shielding gas is 80% Ar by volume and 20% CO2 by volume, the welding current is 210-230A, the arc voltage is 22-24V, the welding speed is 230-250mm / min, the dry extension is 12-18mm, the gas flow rate is 25-30L / min, the arc swing mode is sawtooth, the swing width is 2-3mm, the swing frequency is 55-60 times / min, and the left and right stops are both 0.5s.

Images