CN-122007892-A - Welding, preheating, polishing and detecting integrated method and device for main arch segments of large-span arch bridge

CN122007892ACN 122007892 ACN122007892 ACN 122007892ACN-122007892-A

Abstract

The invention discloses a welding, preheating, polishing and detecting integrated method and device for a main arch segment of a large-span arch bridge, and belongs to the technical field of intelligent manufacturing of bridge steel structures. Through constructing the flexible track base that laminates main arch section hyperboloid of curvature, carry on integrated robot operation, adopt girth welding robot cooperation terminal quadruplex position carousel, integrated preheating, welding, polishing, detection utilize mechanical chucking structure to realize station fast switch over and millimeter level high accuracy auto-lock. The preheating link realizes the temperature closed-loop regulation and control of the welding segment through infrared temperature measurement, the welding link adopts visual tracking to avoid welding path deviation, the polishing link adopts force feedback constant force to ensure welding seam forming quality, and the detection link completes welding seam defect imaging and quality judgment through an ultrasonic phased array full focusing algorithm. The invention realizes one-stop continuous automatic operation of pre-welding preheating, welding, post-welding polishing and nondestructive testing, reduces error accumulation caused by repeated clamping, and improves welding quality stability and operation efficiency.

Inventors

CUI XIAOLU
ZHANG YI
Peng Shuangqian
GAO XU
WEN ZHONGXIN
ZHOU JIANTING
ZHANG HONG
HUANG BO

Assignees

重庆交通大学

Dates

Publication Date: 20260512
Application Date: 20260324

Claims (10)

1. The welding, preheating, polishing and detecting integrated method for the main arch segment of the large-span arch bridge is characterized by comprising the following steps of: constructing a flexible track base attached to the curved surface of the main arch section of the large-span arch bridge, and carrying an integrated girth welding robot on the flexible track base; The method comprises the steps of controlling a girth welding robot in an integrated girth welding robot to move to an initial station along a preset welding track, driving a four-station turntable to rotate through a mechanical clamping structure, switching a preheating station to an operation position and performing self-locking; Starting a preheating station to heat the welding line area, and monitoring the temperature of the welding line in real time When the temperature meets the preset preheating temperature interval, preheating is completed, and the four-station turntable is controlled to be rotationally switched to a welding station; Starting a welding station to perform welding operation, acquiring molten pool images by using a vision module and calculating real-time deviation of a welding line Dynamically adjusting the gesture of the girth welding robot to correct the welding path; after welding is finished, the four-station turntable is controlled to be sequentially switched to a polishing station and a detection station, and force feedback polishing and ultrasonic phased array full-section scanning are respectively carried out on the welding seams to generate a quality detection map.
2. The method for welding, preheating, polishing and detecting the main arch segment of the large-span arch bridge according to claim 1, wherein the specific process of driving the four-station turntable to rotate by the mechanical clamping structure is as follows: releasing the rotary disc locking piece, and driving the rotary disc to rotate by the driving motor Wherein , In order to switch the number of steps for a station, Is a mechanical compensation angle; When the turntable rotates to the target station, circumferential positioning locking is realized by means of insertion matching of the conical clamping groove and the elastic positioning pin, and positioning precision errors are avoided Controlled in the millimeter range.
3. The method for welding, preheating, polishing and detecting the main arch segment of the large-span arch bridge according to claim 2, wherein the temperature of the welding line is monitored in real time And judging whether the specific logic meeting the preheating requirement is as follows: acquiring a weld surface temperature distribution matrix through an infrared temperature sensor Calculating effective preheating temperature at current moment : , wherein, For the area of the pre-heat zone, Is a region Is defined by the total area of the (c), Is a thermal decay weight function based on distance from the center of the heat source; If it is If the temperature is lower than the preset lower threshold, the preheating time is prolonged or the flame power is increased, if If the temperature is higher than the preset upper limit threshold value, heating is stopped and air cooling auxiliary is started until Falls into a preset preheating temperature interval.
4. A method for welding, preheating, grinding and detecting a main arch segment of a large span arch bridge according to claim 3, wherein the vision module is used for collecting images of a molten pool and calculating real-time deviation of a welding seam The specific method of (a) is as follows: After arc strong light is filtered through a narrow-band filter, a molten pool edge characteristic point set is extracted Fitting to obtain the practical weld center line equation ; Will be And a preset theoretical trace line Comparing, calculating the vertical distance from each point on the actual weld joint central line to the theoretical track line, and taking the minimum value as the real-time deviation value : , wherein, Is the unit normal vector (perpendicular to the tangential direction) of the theoretical trajectory line at the corresponding point, and the girth welding robot is based on The lateral offset of the end effector is adjusted in real time so that the offset approaches zero over time.
5. The method for welding, preheating, polishing and detecting the main arch segment of the large-span arch bridge as recited in claim 4, wherein the specific process of ultrasonic phased array full-section scanning is as follows: An ultrasonic probe controlling the detection station moves along the length direction of the welding seam, the cross section of the welding seam is scanned by multi-angle oblique incidence sound waves, and the frequency of the emitted sound waves is that Receiving echo signals ; Reconstructing defect imaging matrix based on full focusing algorithm The formula is: , wherein, For the number of array elements of the probe, Is the first Emitting of each array element The echo signals received by the array elements, For sound waves from transmitting array elements to imaging points Returning the flight time of the receiving array element; According to And the part of the amplitude exceeding the dynamic threshold value judges the position and the size of the defect and automatically generates a quality detection map containing the coordinates of the defect.
6. Welding, preheating and polishing detection integrated device for main arch segments of large-span arch bridge is characterized by comprising: the track module is used for attaching the curved surface of the main arch section of the large-span arch bridge and providing a running base; the shape moving mechanism is arranged on the track module and used for driving the device to move along the track; The ring welding robot is arranged on the shape moving mechanism and used for executing multi-degree-of-freedom motion; the four-station turntable is connected to the tail end flange of the girth welding robot, and preheating stations, welding stations, polishing stations and detecting stations are uniformly distributed on the four-station turntable in the circumferential direction; the mechanical clamping structure is arranged between the four-station turntable and the tail end of the girth welding robot and is used for quick switching and self-locking of the turntable; the vision module is used for collecting the weld image and the molten pool state; And the control module is respectively and electrically connected with the forming mechanism, the girth welding robot, the four-station turntable and each station executor and is used for overall control of the whole-flow operation.
7. The welding, preheating and polishing integrated device for the main arch segment of the large-span arch bridge according to claim 6, wherein the track module is formed by splicing a plurality of flexible stainless steel panels, and a plurality of height-adjustable magnetic seats are arranged at the bottom of each panel; The magnetic base comprises a permanent magnet group and an electromagnet group, and the current of the electromagnet group is adjusted to adapt to the surfaces of arch bridge main arch sections with different thicknesses and materials, so that the adsorption stability of the device during curved surface walking is ensured.
8. The welding, preheating and polishing integrated device for the main arch segment of the large-span arch bridge according to claim 7, wherein the four-station turntable comprises a turntable body, a driving motor and a positioning assembly; the positioning assembly comprises a conical clamping groove arranged on the back surface of the turntable body and an elastic positioning pin arranged at the tail end of the girth welding robot; The mechanical clamping structure drives the turntable body to rotate by an integral multiple of ninety degrees through the driving motor, so that the conical clamping groove of the target station is matched with the insertion of the elastic locating pin to realize circumferential locating and locking, and mechanical self-locking under no servo feedback is realized.
9. The welding, preheating and polishing integrated device for the main arch segment of the large-span arch bridge according to claim 8, wherein preheating stations, welding stations, polishing stations and detecting stations are uniformly distributed on the four-station turntable in the circumferential direction, and specifically: The preheating station comprises an annular flame nozzle, a fuel gas proportional valve, an infrared thermometer and an air cooling device; the air cooling device comprises a compressed air nozzle, wherein when the infrared thermometer detects that the temperature of the welding line exceeds a preset upper limit threshold value, the control module starts the air cooling device, and the welding line area is rapidly cooled by compressed air to enable the temperature to fall back into a preset interval; the welding station comprises a laser welding head, a wire feeder and a vision tracking camera; A narrow-band filter is arranged in front of the visual tracking camera and is used for recognizing weld characteristics in a strong arc light environment; The polishing station comprises a constant force polishing main shaft and a dust hood, wherein a pressure sensor is arranged in the constant force polishing main shaft and is used for realizing closed-loop control of contact force; the detection station comprises an ultrasonic phased array probe and a couplant spraying device, and the ultrasonic phased array probe supports multi-angle electronic scanning.
10. The welding, preheating and polishing integrated device for the main arch segment of the large-span arch bridge is characterized in that the vision module comprises a shell, an infrared laser emitter, an infrared camera, an infrared filter and a universal rotating support, wherein the shell comprises a welding gun clamping mechanism, a variable-space shell, a camera support and a laser support, and the universal rotating support can randomly adjust the angle of the module and adapt to the observation requirement of a welding seam under a complex shielding working condition.

Description

Welding, preheating, polishing and detecting integrated method and device for main arch segments of large-span arch bridge Technical Field The invention relates to the technical field of intelligent manufacturing of bridge steel structures, in particular to a welding, preheating, polishing and detecting integrated method and device for a main arch segment of a large-span arch bridge. Background With a large span arch bridge as a key node of a modern traffic infrastructure, the quality of the main arch segment directly relates to the overall structural safety and service life of the bridge. The main arch segment is usually welded by a large-thickness steel tube, has the remarkable characteristics of long welding line, large restraint stress, complex space curve and the like, and has extremely high requirements on stability and precision of a welding process. However, traditional welding of the main arch segments of the large-span arch bridge is dependent on manpower for a long time, and the whole welding period needs to complete different procedures of preheating, welding, polishing and nondestructive testing. The discretized welding mode has the bottleneck problems of long construction period, low construction efficiency and the like during the closure of the main arch segment of the large-span arch bridge. More importantly, the folding construction of the main arch section of the large-span arch bridge belongs to high-altitude operation, the folding window period is extremely limited, and the main arch section can be expanded with heat and contracted with cold due to day-night temperature difference, so that the linear position of the bridge body is changed. If the welding operation cannot be completed continuously within a limited time window, the temperature variation will seriously affect the weld forming quality and the spatial configuration accuracy of the main arch segment. Therefore, there is a need to develop a method and a device for welding, preheating, polishing and detecting a main arch segment of a large-span arch bridge, which can complete all operations in one station in a folding window period through continuous and rapid integration of multiple operations so as to meet the requirements of high-efficiency and high-quality welding of the main arch segment of the large-span arch bridge. With the deep development of intelligent manufacturing technology, the welding robot technology is increasingly widely applied to the field of bridge steel structure manufacturing, and aims to replace high-intensity manual labor and improve process consistency through an automation means. The current automation solutions mainly focus on the optimization of indoor single procedures or adopt semi-automatic equipment to perform step-by-step operation, and preheating, welding, polishing and nondestructive testing are often completed by different teams and groups at different time periods by using independent equipment. The discretization production mode not only leads to long construction period and low construction efficiency, but also is extremely easy to generate positioning accumulated errors in the processes of repeated hoisting, transferring and re-clamping, and seriously affects the weld joint forming quality and geometric dimension precision. In addition, because the surface of the arch bridge segment presents complex double-curvature characteristics, the traditional rigid track robot is difficult to closely attach to a curved surface to walk, the operation stability is poor, meanwhile, the thick plate welding is extremely sensitive to the uniformity control of a preheating temperature field, the temperature consistency is difficult to ensure by manual operation, and the serious defects of cold cracks and the like are easy to cause. In practical engineering application, workpieces still need to flow frequently among a preheating furnace, a welding station, a grinding table and a detection chamber, which not only increases logistics cost and time consumption, but also introduces uncontrollable quality fluctuation factors due to environmental changes and equipment differences. Particularly, when the welding of high-altitude sections such as the main arch sections of the large-span arch bridge is faced with urgent requirements of urgent construction period and high welding quality requirements of the main arch sections, the construction modes of multiple procedures such as preheating, welding, polishing and detecting are greatly delayed, and the research on the welding preheating polishing detection integration method is more urgent in the research and development of the circular welding robot of the main arch sections of the large-span arch bridge. The existing general automatic equipment often lacks self-adaptive capacity for complex curved surfaces, the phenomenon of data island among various working procedures is serious, and real-time linkage and optimization of technological parameters cannot be realize