Simple positioning method for installation of steel pipe arch truss arch rib corbel

Abstract

The application discloses a simple positioning method, in particular to a simple positioning method for installing a steel pipe arch truss arch rib bracket, and belongs to the technical field of steel structure bridge engineering structure construction process equipment design and manufacturing technology. The simple positioning method can directly and accurately preinstall the bracket on the corresponding position of the steel truss. The simple positioning method comprises arch rib preparation and bracket steel pipe preparation. The simple positioning method first installs a laser alignment alignment instrument in the prepared qualified bracket steel pipe, and makes the measuring light of the laser alignment alignment instrument coincide with the axial center line of the bracket steel pipe. Then, the measuring light emitted by the laser alignment alignment instrument is used to align the steel pipe installation cross line marked on the left arch rib or the right arch rib in advance. Finally, the bracket steel pipe is positioned and welded on the left arch rib or the right arch rib to complete the positioning and installation of the bracket steel pipe.

Description

Technical Field

[0001] This invention relates to a simple positioning method, and more particularly to a simple positioning method for installing the arch rib corbel of a steel pipe arch truss, belonging to the technical field of steel structure bridge engineering construction technology. Background Technology

[0002] Steel structures are characterized by their light weight and fast assembly and construction speed, leading to the increasing adoption of tubular truss structures in large stadiums and steel pipe arch bridge projects. In the manufacturing and installation of steel tubular trusses, the connections between each truss section are mostly achieved using corbel connections. Accurate control of the corbel installation points and angles is crucial to ensure alignment between the corbel and the connecting pipe, guaranteeing aligned butt joints with weld widths meeting design requirements, thus ensuring welding quality and the structural load-bearing capacity. The large distances between each truss section and the numerous angles of the connecting pipes present significant challenges to corbel positioning.

[0003] The conventional method for installing and positioning the bracket is to spot weld the bracket to the connecting pipe, then hoist it into position during a trial installation and securely spot weld the bracket to the corresponding location on the truss. The connecting pipe is then cut and removed before welding the bracket. This process is time-consuming with hoisting equipment, affects the appearance quality of the welded surface, increases the number of assembly, spot welding, and cutting steps, has low assembly efficiency, is not conducive to saving energy, welding materials, and cutting gas, and also increases safety risks.

[0004] The existing installation positioning technology for tubular trusses, "Positioning Method for Intersection Space of Secondary Members of Tubular Trusses" (CN 103389081B), adopts a positioning method that marks the main members. This method is suitable for situations where secondary members are directly connected without corbels, but it cannot be used to determine the installation angle of corbels connecting ultra-long members. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a simple positioning method for installing the arch rib corbel of a steel pipe arch truss, which can directly and accurately pre-install the corbel onto the corresponding position on the steel truss.

[0006] The technical solution adopted to solve the above-mentioned technical problems is: a simple positioning method for the installation of corbels in steel pipe arch trusses, including the preparation of arch ribs and corbel steel pipes. The simple positioning method first installs a laser alignment instrument inside the prepared qualified corbel steel pipe, and makes the measuring light of the laser alignment instrument coincide with the axial center line of the corbel steel pipe. Then, the measuring light emitted by the laser alignment instrument is used to align the qualified left or right arch ribs. Cross lines are installed on the steel pipes marked on the left or right arch ribs in advance. Finally, the corbel steel pipe is positioned and welded to the left or right arch ribs to complete the positioning and installation of the corbel steel pipe.

[0007] Furthermore, during the preparation of the corbel steel pipe, the intersection line that is welded to the left or right arch rib is cut out at the end. When the cross lines of the steel pipe are aligned on the qualified left or right arch rib by measuring the light, in addition to the center point coinciding, the four directional marking lines at the end of the corbel steel pipe with the intersection line are aligned with the cross lines on the corresponding arch ribs.

[0008] The preferred embodiment of the above scheme is that the laser alignment instrument is a laser, and the laser is installed inside the prepared qualified bracket steel pipe by measuring the light beam coaxially with the bracket steel pipe through an adjustable simple mounting frame.

[0009] Furthermore, the adjustable simple mounting frame includes a support and fixing rod assembly and a simple adjustment mechanism. The laser alignment and positioning instrument, through the simple adjustment mechanism and in cooperation with the support and fixing rod assembly, measures the light rays to coincide with the axial center line of the bracket steel pipe and is arranged inside the bracket steel pipe.

[0010] The preferred embodiment of the above scheme is that the support and fixing rod assembly includes three sets of self-supporting support and fixing rods. Each set of self-supporting support and fixing rods, which is evenly distributed circumferentially, is reciprocally connected to a simple adjustment mechanism along its length. The free ends of each set of self-supporting support and fixing rods, once adjusted and in place, are supported on the inner wall of the end of the corbel steel pipe to be installed.

[0011] Furthermore, each set of self-supporting fixing rods includes a self-supporting support base, a support connecting rod, and a movable adjusting component. The movable adjusting component is arranged axially on the support connecting rod. The support connecting rod, adjusted into position by the movable adjusting component in cooperation with a simple adjusting mechanism, is detachably and fixedly connected to the inner wall of the end of the bracket steel pipe to be installed via the self-supporting support base.

[0012] The self-supporting base consists of a disc-shaped magnet, which is covered with a protective steel shell. The free end of the support connecting rod is fixedly connected to the disc-shaped magnet.

[0013] The preferred embodiment of the above scheme is that the simplified adjustment mechanism includes a mounting frame and an adaptive simplified adjustment component. The adaptive simplified adjustment component is arranged at the geometric center within the mounting frame, the laser alignment and positioning instrument is arranged on the adaptive simplified adjustment component, and the support connecting rod is arranged on the simplified adjustment mechanism in an axial reciprocating manner through the cooperation of the movable adjustment component with the adaptive simplified adjustment component in the mounting frame.

[0014] Furthermore, the mounting frame includes a mounting plate and a housing. The housing has a number of through holes on its side wall that are equal to the number of supporting connecting rods. The housing is fitted onto the mounting plate. The adaptive simple adjustment assembly is arranged in the mounting cavity formed by the housing and the mounting plate through the mounting plate. The laser alignment instrument is arranged on the end of the adaptive simple adjustment assembly that protrudes from the end face of the housing. The supporting connecting rods that extend from the through holes at both ends are movably connected to the part of the adaptive simple adjustment assembly located in the mounting cavity through a movable adjustment component.

[0015] The preferred embodiment of the above scheme is that the adaptive simple adjustment component includes at least one set of rolling support bearings, one mounting shaft, and one set of adjusting gears. The adjusting gears are fixed to the inner ring of the rolling support bearings via the mounting shaft. The rolling support bearings are mounted on the mounting sealing plate via the outer ring. The movable adjustment component is a set of racks arranged axially on one side of the support connecting rods. The racks of each support connecting rod simultaneously mesh with the adjusting gears on the mounting shaft under the cooperation of the housing. The laser alignment and positioning instrument is arranged on the end of the mounting shaft that extends out of the housing from the end face.

[0016] Furthermore, the three supporting connecting rods include one solid rod and two slotted rods. The cross-sectional area of ​​the two slotted rods is equal to that of the solid rod. The slots on the two slotted rods gradually increase in size. The three supporting connecting rods are arranged circumferentially, with the solid rod inserted into the slotted rod with the smaller slot, and the slotted rod with the smaller slot inserted into the slotted rod with the larger slot. The rods pass through the housing via through holes.

[0017] A rolling limit bearing is also arranged at the top of the mounting shaft, and the top of the mounting shaft is supported on the end face of the housing by the rolling limit bearing.

[0018] The beneficial effects of this invention are as follows: The technical solution provided in this application is based on the manufactured arch ribs and corbel steel pipes. First, a laser alignment and positioning instrument is installed inside the qualified corbel steel pipe, and the measuring light of the laser alignment and positioning instrument is aligned with the axial center line of the corbel steel pipe. Then, the measuring light emitted by the laser alignment and positioning instrument is used to align and position the qualified left or right arch ribs. Cross lines are installed on the steel pipes marked on the left or right arch ribs beforehand. Finally, the steel pipes are positioned and welded to the left or right arch ribs to complete the positioning and installation of the corbel steel pipes. In this way, when the corbel steel pipes are arranged individually on the arch ribs that need to be connected, the two sets of steel pipes with a connection relationship are aligned and positioned by the laser alignment and positioning instrument. This changes the existing technology that requires spot welding between the corbel steel pipe and the connector, followed by installation and spot welding in the pre-assembled state of the arch rib, and finally removal of the connector before welding the corbel steel pipe to the corresponding position on the arch rib. Instead, it directly installs a laser alignment and positioning device inside the two sets of corbel steel pipes that need to be connected. When installing the corresponding corbel steel pipes to the corresponding positions on the arch rib, the laser alignment and positioning device is used for alignment and positioning. This eliminates the spot welding between the corbel steel pipe and the connector and saves the subsequent dismantling work, achieving the goal of directly and accurately pre-installing the corbels to the corresponding positions on the steel truss arch rib. This not only improves the assembly speed but also effectively ensures the assembly quality. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the laser alignment and positioning instrument installed in the corbel steel involved in the simplified positioning method for installing the corbel of the steel pipe arch truss of the present invention.

[0020] Figure 2 The present invention provides a simplified positioning method for installing the arch rib corbel of a steel pipe arch truss, which involves a three-dimensional structural schematic diagram of an adjustable simplified mounting frame for installing a laser alignment and positioning instrument.

[0021] Figure 3 for Figure 2 The main view;

[0022] Figure 4 The present invention relates to a simplified positioning method for installing the arch rib corbel of a steel pipe arch truss, which involves a three-dimensional structural diagram of an adjustable simplified mounting frame for installing a laser alignment and positioning instrument, with the shell removed.

[0023] Figure 5 for Figure 4 The main view.

[0024] The components in the diagram are labeled as follows: 1. Bracket steel pipe; 2. Laser alignment and positioning device; 3. Adjustable simple mounting bracket; 4. Support and fixing rod assembly; 5. Simple adjustment mechanism; 6. Self-supporting support and fixing rod group; 7. Self-supporting support base; 8. Support connecting rod; 9. Moving adjustment component; 10. Mounting bracket; 11. Adaptive simple adjustment assembly; 12. Mounting sealing plate; 13. Housing; 14. Through hole; 15. Rolling support bearing; 16. Mounting shaft; 17. Adjusting gear; 18. Rolling limit bearing. Detailed Implementation

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4 as well as Figure 5 This invention illustrates a simplified positioning method for installing corbels on steel pipe arch trusses, allowing for precise pre-installation of corbels onto their corresponding positions on the steel truss. The simplified positioning method includes the preparation of the arch rib and the corbel steel pipe. First, a laser alignment instrument 2 is installed inside the prepared corbel steel pipe 1, aligning the measuring light beam of the laser alignment instrument 2 with the axial centerline of the corbel steel pipe 1. Then, the measuring light beam emitted by the laser alignment instrument 2 is used to align the pipe with the pre-marked crosshairs on the left or right arch rib. Finally, the corbel steel pipe 1 is positioned and welded to the left or right arch rib, completing the positioning and installation of the corbel steel pipe 1. The technical solution provided in this application is based on the manufactured arch ribs and corbel steel pipes. First, a laser alignment and positioning device is installed inside the qualified corbel steel pipe, and the measuring light of the laser alignment and positioning device is aligned with the axial centerline of the corbel steel pipe. Then, the measuring light emitted by the laser alignment and positioning device is used to align and position the qualified left or right arch rib. Crosshairs are installed on the steel pipe marked on the left or right arch rib beforehand. Finally, the steel pipe is positioned and welded to the left or right arch rib, completing the positioning and installation of the corbel steel pipe. Thus, when the corbel steel pipe is individually placed on the arch rib that needs to be connected, the two sets of steel pipes with a connection relationship are aligned and positioned using the laser alignment and positioning device. This changes the existing technology that requires spot welding between the corbel steel pipe and the connector, followed by installation and spot welding in the pre-assembled state of the arch rib, and finally removal of the connector before welding the corbel steel pipe to the corresponding position on the arch rib. Instead, it directly installs a laser alignment and positioning device inside the two sets of corbel steel pipes that need to be connected. When installing the corresponding corbel steel pipes to the corresponding positions on the arch rib, the laser alignment and positioning device is used for alignment and positioning. This eliminates the spot welding between the corbel steel pipe and the connector and saves the subsequent dismantling work, achieving the goal of directly and accurately pre-installing the corbels to the corresponding positions on the steel truss arch rib. This not only improves the assembly speed but also effectively ensures the assembly quality.

[0026] Accordingly, according to the process flow, in order to improve assembly efficiency and reduce auxiliary processes in the equipment process, this application, when preparing the bracket steel pipe 1, simultaneously cuts out the intersection line at the end that is welded to the left or right arch rib. When aligning the steel pipe installation crosshairs on the qualified left or right arch rib by measuring the light, in addition to the center point coinciding, the four directional marking lines at the end of the bracket steel pipe 1 with the intersection line are aligned with the crosshairs on the corresponding arch ribs. Furthermore, considering the existing technology, in order to make the most of existing standard parts, the laser alignment and positioning instrument 2 described in this application is a laser. The laser is installed inside the qualified bracket steel pipe 1, with the measuring light coaxial with the bracket steel pipe 1 via an adjustable simple mounting frame 3. The adjustable simple mounting frame 3 described in this application includes a support fixing rod assembly 4 and a simple adjustment mechanism 5. The laser alignment and positioning instrument 2, with the cooperation of the support fixing rod assembly 4 and the simple adjustment mechanism 5, is arranged inside the bracket steel pipe 1 with the measuring light coinciding with the axial center line of the bracket steel pipe 1. The support and fixing rod assembly 4 includes three sets of self-supporting support and fixing rod groups 6. Each set of self-supporting support and fixing rod groups 6, evenly distributed circumferentially, is reciprocally connected to a simple adjustment mechanism 5 along its length. The free ends of each set of self-supporting support and fixing rod groups 6, once adjusted and positioned, are supported on the inner wall of the end of the bracket steel pipe to be installed. Each set of self-supporting support and fixing rod groups 6 includes a self-supporting support base 7, a support connecting rod 8, and a movable adjustment component 9. The movable adjustment component 9 is axially arranged on the support connecting rod 8. With the cooperation of the simple adjustment mechanism 5, the adjusted support connecting rod 8 is detachably and fixedly connected to the inner wall of the end of the bracket steel pipe to be installed via the self-supporting support base 7.

[0027] Furthermore, given that the steel pipe truss is made entirely of steel, to facilitate the placement of the laser within the corbel steel pipe 2 via the adjustable simple mounting bracket 3, the self-supporting base 7 described in this application is composed of a disc-shaped magnet. A protective steel shell covers the outside of the disc-shaped magnet, and the free end of the support connecting rod 8 is fixedly connected to the disc-shaped magnet. At this time, the simple adjustment mechanism 5 described in this application includes a mounting bracket 10 and an adaptive simple adjustment component 11. The adaptive simple adjustment component 11 is located at the geometric center within the mounting bracket 10. The laser alignment and positioning instrument 2 is positioned on the adaptive simple adjustment component 11. The support connecting rod 8 is arranged on the simple adjustment mechanism 5, axially reciprocating in cooperation with the adaptive simple adjustment component 11 via a movable adjustment component 9 on the mounting bracket 10. Accordingly, the mounting bracket 10 of this application includes a mounting cover plate 12 and a housing 13. The housing 13 has a number of through holes 14 on its side wall that are equal to the number of support connecting rods 8. The housing 13 is fitted onto the mounting cover plate 12. The adaptive simple adjustment component 11 is arranged in the mounting cavity formed by the housing 13 and the mounting cover plate 12 through the mounting cover plate 12. The laser alignment instrument 2 is arranged on the end of the adaptive simple adjustment component 11 that protrudes from the end face of the housing 13. The support connecting rods 8 that extend from both ends through the through holes 14 are movably connected to the portion of the adaptive simple adjustment component 11 located in the mounting cavity through the movable adjustment component 9. The adaptive simple adjustment assembly 11 described in this application includes at least a set of rolling support bearings 15, a mounting shaft 16, and a set of adjusting gears 17. The adjusting gears 17 are fixed on the inner ring of the rolling support bearings 15 via the mounting shaft 16. The rolling support bearings 15 are mounted on the mounting sealing plate 12 via the outer ring. The movable adjustment element 9 is a set of racks arranged axially on one side of the support connecting rod 8. The racks of each support connecting rod 8 simultaneously mesh with the adjusting gears 17 on the mounting shaft 16 under the cooperation of the housing 13. The laser alignment and positioning instrument 2 is arranged on the end of the mounting shaft 16 that extends out of the housing 13 from the end face. Meanwhile, in order to ensure that each group of self-supporting fixing rods 6 is as symmetrical as possible in terms of weight and to avoid inaccurate position detection due to weight during use, the three supporting connecting rods 8 of this application include one solid rod and two slotted rods. The cross-sectional area of ​​the two slotted rods is equal to that of the solid rod. The slots on the two slotted rods gradually increase in size. The three supporting connecting rods arranged circumferentially are inserted into the slotted rod with the smaller slot, and the slotted rod with the smaller slot is inserted into the slotted rod with the larger slot. The rod passes through the housing through the through hole 14. A rolling limit bearing 18 is also arranged on the top of the mounting shaft 16. The top of the mounting shaft 16 is supported on the end face of the housing 13 by the rolling limit bearing 18.

[0028] In summary, compared with traditional methods and existing technologies, the simplified positioning method for installing corbel steel pipes provided in this application primarily utilizes bidirectional aurora technology for precise alignment of assembly points. Simultaneously, it employs a circular magnetic suction device and synchronous telescopic support rods. These multiple technologies ensure that the aurora beam of the device is parallel to the corbel and located at the center of the corbel's circular tube. Its installation and disassembly are simple and easy to use, achieving precise positioning and installation of the corbel connection. This eliminates the pre-welding and subsequent cutting processes between the connecting pipe and the corbel during workshop installation, reducing overhead crane usage and thus reducing labor hours, equipment usage, and auxiliary material consumption. This improves production efficiency and contributes to energy conservation and emission reduction. It also provides a simple and reliable positioning method for on-site corbel installation, ensuring the quality of the pipe truss installation.

[0029] The technical solution of this application will be further described below through specific embodiments:

[0030] In the manufacturing and construction of steel truss structures, the connection between each truss section is mostly achieved by connecting pipes and corbels. Corbel assembly is typically completed in the workshop, but for large trusses, their dimensions often exceed transportation limits, making them unsuitable for transport after corbel installation. Therefore, corbels must be assembled on-site. In the workshop, the assembly and positioning of corbels occupies overhead cranes for extended periods, requiring temporary welding and segmentation of the corbels and connecting pipes. This increases the number of processes, energy consumption, and auxiliary materials required. Segmentation also affects the quality of the beveled joint surface, impacting manufacturing safety. On-site corbel assembly lacks the assembly equipment available in the workshop, making it difficult to guarantee positioning accuracy. To address this technical challenge, a method for installing and positioning corbels in truss structures was developed.

[0031] The present application includes a disc-shaped magnetic support foot, protected by an iron shell of the same shape; a support rod with a rack; a fixing plate at the top of the support rod; a cylindrical outer shell with a rectangular hole; end plates with a laser mounting base and a bearing mounting base; a gear roller shaft that matches the rack of the support rod; and matching bearings.

[0032] During installation, first place the pipe section to be installed horizontally, retract the support rod to the appropriate length, magnetically attach the top of the steel pipe, and extend the support rod under its own weight until the other two support rods are magnetically attached to the inner wall of the steel pipe. This further ensures that the device is located on the vertical section of the steel pipe and that the laser line is parallel to the steel pipe.

[0033] Example 1

[0034] Hereinafter, the direction of the support rod's forward and backward movement is called the front-back of the support rod, the side of the support rod that contacts the rotor is called the right side of the support rod, and the directions of the other two sides of the support rod are called the up-down of the support rod.

[0035] 1. By combining three support rods with one rotor, a "coordinated advance and retreat" configuration is formed, ensuring that the advance and retreat lengths of the three support rods are consistent. This guarantees that the distance from the center point of the device to the steel pipe wall is equal in all directions. Based on the definition of a circle, the device can be located on the vertical section of the pipe. The tooth pitch on the support rods and rotor is 0.5–2 mm. Too small a tooth pitch will result in high resistance and slow speed during the advance and retreat of the support rods, while too large a tooth pitch may lead to reduced accuracy.

[0036] 2. The feet of the support rod are disc-shaped magnets, encased in an iron shell to prevent damage from impacts, allowing for easy magnetic attraction to the steel pipe wall. Since the contact points between the disc-shaped magnets and the pipe wall are always two points on the pipe wall, and these two points are always located on the vertical section of the steel pipe, this further ensures that the device is positioned on the vertical section of the steel pipe. All three disc-shaped magnets are of the same size.

[0037] 3. The support rod is perpendicularly and fixedly connected to the shell of the disc-shaped magnet, and the eccentric distance is equal to the distance from the support rod to the axis.

[0038] 4. The three support rods are symmetrically staggered vertically to maintain a balanced load on the rotor during transmission, preventing eccentric load distribution. The first support rod passes through the center of the second support rod, and the second support rod passes through the center of the third support rod, with a 1-2mm gap between them to prevent friction. All three support rods have equal cross-sectional areas, ensuring equal weight. The second and third support rods, now divided into two, are fixed at one end to the magnet housing and at the other end to a 1-2mm thick elliptical iron sheet, thus fixing their spacing.

[0039] 5. The rotor consists of a gear and a shaft, forming a single unit with a hollow, threaded core for mounting the dual-head laser. The gear length is flush with or slightly exceeds the length of the third support rod by 1-2 mm. The shaft diameter and length match the bearing's inner diameter and are fixedly connected to the bearing's inner ring.

[0040] 6. The outer ring of the bearing is fixed to the stator. The bearings on the upper and lower sides of the rotor are symmetrically arranged.

[0041] 7. The side support cylinder is 1-2mm thick, providing good rigidity. Rectangular holes matching the cross-sectional size of the support rods are opened at the positions of the three support rods, with a 3mm gap larger than the support rods. Small rollers with a diameter of 3mm are installed on the upper and lower sides of the openings. Their function is to clamp the support rods from the top, bottom, and toothless surfaces without obstructing their movement.

[0042] 8. The rotor is hollow at the center with threads on the inside for mounting the dual-head laser. The rotor, stator, and support rods are spatially perpendicular to each other, ensuring that the aurora of the laser is perpendicular to the plane defined by the three support rods after installation.

[0043] 9. When using, first place the pipe section to be installed horizontally, retract the support rod to the appropriate length, first magnetically attach the top of the steel pipe, and then extend the support rod under its own weight until the other two support rods are magnetically attached to the inner wall of the steel pipe. This further ensures that the device is located on the vertical section of the steel pipe and that the laser line is parallel to the steel pipe.

Claims

1. A simplified positioning method for installing the arch rib corbel of a steel pipe arch truss, comprising the preparation of the arch rib and the preparation of the corbel steel pipe, characterized in that: The simplified positioning method involves first installing a laser alignment instrument (2) inside a qualified corbel steel pipe (1), and aligning the measuring light of the laser alignment instrument (2) with the axial centerline of the corbel steel pipe (1). Then, the measuring light emitted by the laser alignment instrument (2) is used to align the pipe on the qualified left or right arch rib. Beforehand, cross lines are installed on the steel pipe marked on the left or right arch rib. Finally, the corbel steel pipe (1) is positioned and welded to the left or right arch rib to complete the positioning and installation of the corbel steel pipe (1). The laser alignment instrument (2) is a laser. The laser is installed inside the qualified bracket steel pipe (1) with the measuring light beam coaxial with the bracket steel pipe (1) through an adjustable simple mounting bracket (3). The adjustable simple mounting bracket (3) includes a support and fixing rod assembly (4) and a simple adjustment mechanism (5). The laser alignment instrument (2) is arranged inside the bracket steel pipe (1) with the support and fixing rod assembly (4) and the measuring light aligning with the axial center line of the bracket steel pipe (1) through the simple adjustment mechanism (5). The support and fixing rod assembly (4) includes three sets of self-supporting support and fixing rod groups (6). Each set of self-supporting support and fixing rod groups (6) is movably connected to a simple adjustment mechanism (5) along its length direction and is evenly distributed circumferentially. The free ends of each set of self-supporting support and fixing rod groups (6) in the adjusted position are supported on the inner side wall of the end of the corbel steel pipe to be installed. Each set of self-supporting fixed rods (6) includes a self-supporting support base (7), a support connecting rod (8), and a movable adjusting component (9). The movable adjusting component (9) is arranged axially on the support connecting rod (8). The support connecting rod (8) is adjusted into position by the movable adjusting component (9) in cooperation with the simple adjusting mechanism (5). It is then detachably and fixedly connected to the inner wall of the end of the bracket steel pipe to be installed through the self-supporting support base (7). The simplified adjustment mechanism (5) includes a mounting frame (10) and an adaptive simplified adjustment assembly (11). The adaptive simplified adjustment assembly (11) is located at the geometric center within the mounting frame (10). The laser alignment instrument (2) is mounted on the adaptive simplified adjustment assembly (11). The support connecting rod (8) is axially reciprocating on the simplified adjustment mechanism (5) through the cooperation of the movable adjustment component (9) with the adaptive simplified adjustment assembly (11) on the mounting frame (10). The adaptive simple adjustment assembly (11) includes at least one set of rolling support bearings (15), one mounting shaft (16), and one set of adjusting gears (17). The adjusting gears (17) are fixed on the inner ring of the rolling support bearings (15) via the mounting shaft (16). The rolling support bearings (15) are mounted on the mounting sealing plate (12) via the outer ring. The movable adjustment component (9) is a set of racks arranged axially on one side of the support connecting rods (8). The racks of each support connecting rod (8) mesh with the adjusting gears (17) on the mounting shaft (16) simultaneously in cooperation with the housing (13). The laser alignment instrument (2) is arranged on the end of the mounting shaft (16) that extends out of the housing (13) from the end face. The three supporting connecting rods (8) include one solid rod and two slotted rods. The cross-sectional area of ​​the two slotted rods is equal to that of the solid rod. The slots on the two slotted rods gradually increase in size. The three supporting connecting rods are arranged circumferentially, with the solid rod inserted into the slotted rod with the smaller slot, and the slotted rod with the smaller slot inserted into the slotted rod with the larger slot. The rods pass through the shell through the through hole (14). A rolling limit bearing (18) is also arranged on the top of the mounting shaft (16), and the top of the mounting shaft (16) is supported on the end face of the housing (13) by the rolling limit bearing (18).

2. The simplified positioning method for installing the corbel of a steel pipe arch truss according to claim 1, characterized in that: When preparing the corbel steel pipe (1), the intersection line that is welded to the left or right arch rib is cut out at the same time. When the cross line of the steel pipe is installed on the qualified left or right arch rib by measuring the light, in addition to the center point coinciding, the four directional marking lines of the corbel steel pipe (1) with the intersection line cut out are aligned with the cross lines on the corresponding arch ribs.

3. The simplified positioning method for installing the corbel of a steel pipe arch truss according to claim 1 or 2, characterized in that: The self-supporting base (7) is composed of a disc-shaped magnet. A protective steel shell is wrapped around the outside of the disc-shaped magnet. The free end of the support connecting rod (8) is fixedly connected to the disc-shaped magnet.

4. The simplified positioning method for installing the corbel of a steel pipe arch truss according to claim 3, characterized in that: The mounting bracket (10) includes a mounting plate (12) and a housing (13). The housing (13) has a number of through holes (14) on its side wall that are equal to the number of support connecting rods (8). The housing (13) is fitted onto the mounting plate (12). The adaptive simple adjustment component (11) is arranged in the mounting cavity formed by the housing (13) and the mounting plate (12) through the mounting plate (12). The laser alignment instrument (2) is arranged on the end of the adaptive simple adjustment component (11) that protrudes from the end face of the housing (13). The support connecting rods (8) that extend from both ends through the through holes (14) are movably connected to the part of the adaptive simple adjustment component (11) located in the mounting cavity through the movable adjustment component (9).

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