Special-shaped tubular column bracket three-dimensional positioning and assembling method and drawing labeling system

Abstract

The invention discloses a special-shaped tubular column bracket three-dimensional positioning and assembling method and a drawing marking system, and belongs to the technical field of steel structure machining. According to the method, the center line of a quartered cross serves as the reference, the arc length of the root of a bracket, the space included angle and the flange vertical distance are converted into measurable linear sizes, upper and lower flanges are fixed in a jig frame through a normalized triangular support, and welding is conducted after arc length difference and diagonal two-stage actual measurement closed loop; and a drawing marking system gives out all sizes and diagonal theoretical values extracted by the three-dimensional model on the same 1: 1 expanded strip graph, so that a design-manufacturing data closed loop is realized. According to the method, multidirectional bracket millimeter-level positioning can be completed in a common workshop without numerical control equipment, the datum drift, the drawing recognition error and the rework rate are remarkably reduced, and the method is suitable for batch manufacturing of bracket circular pipe columns with space angles in super high-rise and large-span space steel structures.

Description

Technical Field

[0001] This invention relates to the field of steel structure building technology, specifically to a three-dimensional positioning and assembly method and drawing annotation system for irregularly shaped circular tube column brackets. Background Technology

[0002] In super high-rise, long-span, and complex spatial steel structures, circular tubular columns are widely used due to their isotropic strength and excellent bending and torsional resistance. To meet the requirements of building facade recesses, cantilevered sections, and multi-directional connections of floor steel beams, circular tubular columns typically require 2 to 6 corbels (including connecting plates or node plates) arranged radially at spatial angles. This type of "irregularly shaped circular tubular column-spatial corbel" combination joint has the following manufacturing characteristics: The surface of the cylindrical tube is a single-curvature spatial curved surface with no clear edges, and the traditional "cross center line" cannot be directly extended into a visible reference. The brackets are numerous and at various angles, exhibiting three-dimensional degrees of freedom: pitch, twist, and yaw, resulting in complex spatial geometry. The columns are often shipped in sections and need to be pre-assembled as a whole in the workshop to ensure successful hoisting on site in one go.

[0003] However, the existing workshop manufacturing process is still at the stage of "two-dimensional drawings + manual layout", and the specific process is as follows: a) The design unit provides two-dimensional detailed drawings, which only give planar dimensions such as "column center elevation + corbel centerline projection angle + corbel flange thickness"; b) Manufacturing personnel use measuring tapes, spirit levels, and simple angle rulers to "find the center, draw a cross, and snap chalk lines" on the surface of the round tube, and determine the position of the root of the corbel based on experience; c) Use angle steel or steel bars for temporary spot welding support, manually pry and adjust the spatial posture of the bracket, and then spot weld it in place; d) Use a right-angle ruler and a small steel ruler to check the local gaps before proceeding to the final welding.

[0004] The above methods bring about three common problems across industries: (a) Low positioning accuracy The lack of a stable reference on the surface of the round pipe means that the width of the manually drawn lines is 1 to 1.5 mm. With multiple projection transformations, the positioning error of the arc at the root of the bracket is generally ≥ 5 mm. The misalignment rate of bolt holes on site is as high as 20% to 30%, requiring on-site hole enlargement or the addition of shims, which weakens the rigidity of the joint and increases the amount of high-altitude work.

[0005] (ii) Low assembly efficiency A single Φ800×30 mm round tube column with four space brackets requires 2 to 2.5 hours of manual adjustment, knocking, prying, and measurement cycles, which takes up a long time in the jig and seriously restricts mass production. In winter or during night shifts, the efficiency drops by more than 30%.

[0006] (iii) Difficulty in reading drawings and high error rate Two-dimensional "center height + angle" cannot intuitively reflect "spatial twist angle". Workers need to repeatedly compare with three-dimensional models or actual objects on site. The error rate of reading the drawings is ≥15%. Once there is a misunderstanding, batch scrapping will occur due to issues such as reverse twisting of the brackets and inversion of the upper and lower flanges, resulting in direct economic losses of tens of thousands of yuan per piece.

[0007] In recent years, some companies have tried to introduce laser trackers, photogrammetry, or CNC gantry milling machines, but the equipment investment exceeds 3 million yuan per set, has poor adaptability to 10-meter heavy-duty round pipe columns, and requires constant temperature and humidity workshops, which is not compatible with the "multi-variety, small-batch, fast-paced" production mode of steel structure workshops, making it difficult to promote on a large scale.

[0008] In summary, what is needed now is a high-precision, high-efficiency assembly solution for irregularly shaped round tube columns and brackets that does not rely on expensive CNC equipment and can be implemented in ordinary heavy steel workshops. This solution would reduce spatial positioning errors to within 2mm, shorten single-piece assembly time by more than 30%, and eliminate rework caused by ambiguity in drawings. Summary of the Invention

[0009] This invention aims to overcome the shortcomings of existing technologies and provide a three-dimensional positioning and assembly method and drawing annotation system for irregularly shaped circular tube column brackets, solving the problems of missing spatial positioning benchmarks, large assembly errors, and low workshop efficiency in multi-directional circular tube column brackets.

[0010] To solve the above-mentioned technical problems, the present invention is implemented as follows: A method for three-dimensional positioning and assembly of irregularly shaped circular tube column brackets, characterized by the following steps: Step 1: Establish four quarter points distributed at 90° on the outer surface of the cylindrical tube, and connect the four points to form a cross center line to form a circumferential absolute position reference; Step 2: Starting from any quarter point, mark the arc length of the starting point of the bracket root on the outer surface of the circular tube in the circumferential direction, and simultaneously mark the difference in circumferential arc length between adjacent bracket roots; Step 3: When the corbel is not perpendicular to the central axis of the cylindrical tube, mark the angle between the center line of the corbel web and the axis of the tube, and the shortest perpendicular distance from the end of the corbel flange to the outer surface of the cylindrical tube. Step 4: Place the round tube column horizontally on the jig, and perform initial positioning of the bracket according to the arc length, included angle and vertical distance, and use temporary triangular supports to fix the upper and lower flange plates of the bracket; Step 5: After spot welding, measure the difference in arc length at the root of adjacent brackets. If the deviation is greater than the allowable value given in the drawing, loosen the spot weld and readjust. Step Six: Measure the diagonal length between the center of the ends of adjacent brackets in the upper and lower layers. If the difference between the measured value and the theoretical value on the drawing is greater than the allowable value given on the drawing, return to Step Four to readjust. Step 7: After completing the positioning of all brackets, proceed to the formal welding and perform formal welding according to the drawing requirements.

[0011] Furthermore, the establishment of the quarter points in step one is refined as follows: two mutually perpendicular planes passing through the center of the tube are projected onto both ends and the outer surface of the cylindrical tube using a laser line-laying instrument. These planes intersect the tube wall to obtain four quarter points. The four points are connected to form a cross center line, and the arc length between the four points is measured with a tape measure. If the difference in diagonal arc length is ≤1 mm, the benchmark is confirmed. This refinement eliminates the error of manual line width marking, allowing the repeatability accuracy of the benchmark to be verified on-site.

[0012] Furthermore, the method also introduces synchronous positioning of the inner diaphragm: using the end face of the lower tube as a reference, the inner diaphragm is positioned according to the axial distance indicated in the detailed drawing, and the distance from the outer ring of the inner diaphragm to the four radial lines of the cross center line is measured to ensure that the alignment error between the inner diaphragm and the subsequent bracket flange plate is ≤1 mm. This ensures that the plane for the transfer of interlayer internal forces is on the same cross section as the bracket flange, reducing subsequent assembly stress.

[0013] Furthermore, the temporary triangular supports are standardized into steel strips of the same material, with a thickness t=16 mm±1 mm, a width b=30 mm±1 mm, and a length L=200 mm±5 mm. Both ends are beveled at 30° and spot-welded to the upper and lower flange plates and the pipe wall at a 45° angle to form a detachable flange spacing retainer. This dimensional chain balances on-site cutting allowance with welding accessibility, achieving "ready-to-use" standardized chemical equipment.

[0014] Furthermore, after the temporary triangular supports are removed, they are cleaned using carbon arc gouging or an angle grinder. Repair welding is performed using E50 type welding rods, with a weld length ≥ 50 mm, followed by grinding to a smooth finish. This repair process ensures the geometric continuity and fatigue performance of the column surface, preventing the removed area from becoming a new stress concentration source.

[0015] Furthermore, the formal welding sequence is defined as "lower layer first, then upper layer, symmetrical welding at 120° intervals." This sequence utilizes symmetrical heat input to balance the welding angle deformation of the circular tube column, reducing the amount of post-weld correction work.

[0016] Furthermore, this invention also provides a drawing annotation system for implementing the above method, comprising: a reference module for establishing quarter points on the end face or outer surface of the circular tube column and forming a cross center line; an arc length positioning module for annotating the arc length dimension of the starting point of the corbel root and the circumferential arc length difference of adjacent corbel roots, with the quarter points as the starting point; a spatial angle-perpendicular distance module for annotating the angle between the corbel web and the column axis and the shortest vertical distance from the flange end to the outer surface of the column; and a redundancy verification module for providing the theoretical diagonal length between the centers of the ends of adjacent corbels on the upper and lower layers in the additional area of ​​the drawing for on-site measurement and comparison; wherein all dimensions are arranged proportionally to the 1:1 unfolded strip diagram of the outer surface of the circular tube, forming a printable single drawing carrier. This system transforms three-dimensional spatial relationships into measurable linear / angular dimensions, allowing workshops to construct according to the drawings without the need for three-dimensional drawing interpretation.

[0017] Furthermore, the theoretical length of the diagonal in the drawing annotation system is extracted from the 3D model and written back into the drawing remarks column, forming a design-manufacturing closed-loop verification, avoiding manual input errors, and ensuring that the actual measured value on site corresponds one-to-one with the theoretical value.

[0018] Through the aforementioned progressive technical measures, this invention can achieve millimeter-level positioning of multi-directional brackets for irregularly shaped circular columns under ordinary heavy steel workshop conditions, and significantly reduce errors in drawing interpretation and assembly.

[0019] The beneficial effects of this invention are as follows: As can be seen from the above technical solution, this application provides a three-dimensional positioning and assembly method and drawing annotation system for irregularly shaped circular pipe column brackets. First, the benchmark system is simple and reliable, and has strong on-site applicability. By establishing four points on the outer surface of the circular pipe column and connecting them to form a cross center line, the traditional alignment method relying on manual line marking or expensive CNC equipment is replaced. The "diagonal arc difference ≤ 1 mm" judgment condition, which is reused by the laser line laying instrument and the measuring tape, allows the benchmark accuracy to be verified on-site, eliminates the cumulative error of long-distance projection, and provides a unique and traceable "zero reference" for the positioning of all subsequent brackets, greatly reducing the risk of benchmark drift.

[0020] Secondly, the three-dimensional attitude is converted into measurable linear data, reducing the difficulty of drawing interpretation and operation simultaneously. Starting from the quarter point, the circumferential arc length, the difference between adjacent arc lengths, the web angle, and the flange vertical distance are all marked on the 1:1 unfolded strip diagram. Workers can complete all remeasurements using ordinary tape measures and angle gauges. With the theoretical diagonal length given in the supplementary area of ​​the drawing, only two levels of on-site measurement are needed to determine whether the assembly is qualified, avoiding the time-consuming process of repeated hammering and prying of the traditional "sample + trial assembly", and significantly shortening the time that a single part occupies the jig.

[0021] Third, standardized temporary triangular supports balance positioning rigidity and welding accessibility while controlling welding deformation. 16mm×30mm steel strips with 30° bevels at both ends are spot-welded at a 45° angle to the flanges and pipe wall, forming a standardized "flange spacing retainer." This continuously constrains the flange spacing during welding in all positions. After welding, the supports are removed and repaired by welding and grinding in the order of "lower layer first, then upper layer, symmetrical welding at 120° intervals." This ensures the geometric continuity of the column surface and balances the angular deformation of the circular pipe column through symmetrical heat input, reducing the workload of subsequent flame straightening.

[0022] Finally, the drawing annotation system is directly integrated with the 3D model data, forming a design-manufacturing closed loop. The theoretical length of the diagonal is automatically extracted by models such as Tekla and written back into the drawing's remarks column. The on-site measurement results correspond one-to-one with the theoretical values, eliminating manual input errors. All dimensions are integrated onto a single printable page, allowing the workshop to construct according to the drawings without additional 3D drawing interpretation training. This significantly reduces the rework rate caused by misunderstandings of the drawings and improves the overall manufacturing quality stability. Attached Figure Description

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: Figure 1 A schematic diagram showing the control points and their connecting lines positioned on the lines connecting the quarter points.

[0024] Figure 2 A schematic diagram showing the positioning arc length and positioning verification dimensions of the cow leg web plate.

[0025] Figure 3 This is a schematic diagram showing the positioning points and verification dimensions of the cow leg's web plate.

[0026] Figure 4 This is a schematic diagram of the center line of the cross on a circular tube.

[0027] Figure 5 This is a schematic diagram showing the positioning points and dimensions of the inner partition.

[0028] Figure 6 This is a schematic diagram of the flange triangular support. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application. A method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket, the specific operation steps of which are as follows: I. Method of Marking Processing Drawings Step 1.1: Mark the quarter points like Figure 1 As shown: When marking in the machining drawing, mark the quarter points on the cross-sectional view of the circular tube, and draw four quadrants with the center of the circle as the origin; if the circular tube is a single curved tube, the center line should be on the line connecting the left and right or upper and lower quadrant points; Quarter points: the four equal division points of the circumference of the circular tube based on the central angle of 90°, the lines connecting them are perpendicular to each other, and the intersection point is located at the center of the circular tube, dividing the circular tube into four quadrants on the surface of the circular tube.

[0030] Step 1.2: Mark the positioning arc length of the corbel. The positioning of the corbel or connecting plate of the circular tube column on the steel column plane is based on the four quarter points described in step one (i.e., the four quadrant points of the circular tube cross-section). The arc length of its root on the surface of the circular tube is marked, and the positioning arc length of adjacent corbels is also marked to assist in detection and positioning. Figure 2 As shown.

[0031] Step 1.3: Mark the angle between the brackets and the vertical distance. If the corbel and the circular column are not perpendicular in the elevation, then the included angle between the corbel and the circular column, as well as the vertical distance from the end of the corbel flange to the circular column, should be indicated. If the vertical distance is not indicated on the drawing, this data can be calculated using trigonometric functions. Figure 3 As shown.

[0032] II. Assembly of Circular Tube Columns Step 2.1: Mark the center line of the cross on the circular tube. Create positioning lines for the round pipe. Place the round pipe on a flat and stable jig. Use a spirit level and laser marking instrument to measure the center line of the crosshairs on the pipe (reflected on the pipe surface as the quarter points). Measure the arc length between the four positioning points with a tape measure, and verify the accuracy of the determined positioning points. With the center lines (quarter points) of the round pipe determined at both ends, use a plumb line to mark the positioning lines on the pipe wall. Figure 4 As shown.

[0033] Step 2.2: Assembly of the inner partition Assemble the inner baffle, ensuring it aligns with the corbel flange after assembly. Position the inner ring plate using the lower tube end as a reference, measuring the lengths of the inner baffle along the four radial lines of the circular tube for accurate positioning. Figure 5 As shown.

[0034] Step 2.3: Verification of Circular Tube Dimensions For complex structures like multi-angled circular tube columns, the detailed drawings are further refined to create circular tube connection process drawings. Each segment of the circular tube column is then assembled according to these drawings, controlling the overall precision of the column body. The dimensions of the circular tube connections are then verified to ensure that qualified components proceed to the next process. Figure 1 As shown.

[0035] Step 2.4: Assembling the calf leg Ensure the planar dimensions of the corbel flange. Based on the characteristic that the corbel web is perpendicular to the bottom surface, the inclination angle of this section of the circular tube column relative to the horizontal line is used to position the corbel web, ensuring the angular dimensions of the inter-story space. To ensure accurate installation of the corbel before welding, temporary triangular supports are needed during the assembly of the upper and lower flange plates. These supports fix the angle between the flange plate and the column body, and the distance between the upper and lower flanges. The supports are made of steel strips of the same material, with a cross-sectional thickness t ≥ 16mm and a width b ≥ 30mm, and are welded at both ends for fixation. The supporting steel strips are under tension and form a 45° angle with the flange plate; they are removed after the component is fabricated. Figure 6 As shown. During assembly, ensure that the bevels of the upper and lower flanges of the bracket face outwards to provide space for subsequent welding.

[0036] Step 2.5: Verify assembly dimensions The steel column brackets, initially positioned, are spot-welded onto the cylindrical column. The positioned brackets are then inspected and verified in conjunction with the positioning dimensions and the flange circumference dimensions. All upper and lower flanges of the brackets are checked to ensure the installation accuracy of the brackets.

[0037] Step 2.6: Space Dimension Verification Verify whether the corbels between the upper and lower layers of the steel column are on the same elevation. At the same time, use 3D modeling software such as Tekla to measure the diagonal distance between the center of the ends of adjacent corbels on the upper and lower layers to help detect the positioning accuracy and prevent individual corbel deviations from affecting the overall component quality.

[0038] The eccentric components of the circular tube columns and their special corbel joints, with multiple angles and complex spatial relationships, cannot display all the information of the circular tube column components based solely on drawings, causing difficulties for the processing workers in interpreting the drawings. At this time, by further refining the drawings and combining the display characteristics of the Tekla model, the component information is reflected intuitively to the processing and inspection personnel, avoiding the occurrence of accuracy deviation problems and affecting on-site installation.

[0039] By studying the manufacturing process, key steps affecting project quality and assembly accuracy were identified. Based on practical considerations, this resulted in a 40% improvement in bracket positioning efficiency and a reduction in single-component assembly time from 2 hours to 1.2 hours. Furthermore, Tekla model-assisted inspection reduced the error rate to below 2mm.

[0040] The above are merely embodiments provided in this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for three-dimensional positioning and assembly of irregularly shaped circular tube column brackets, characterized in that... Includes the following steps: Step 1: Establish four quarter points distributed at 90° on the outer surface of the cylindrical tube, and connect the four points to form a cross center line to form a circumferential absolute position reference; Step 2: Starting from any quarter point, mark the arc length of the starting point of the bracket root on the outer surface of the circular tube in the circumferential direction, and simultaneously mark the difference in circumferential arc length between adjacent bracket roots; Step 3: When the corbel is not perpendicular to the central axis of the cylindrical tube, mark the angle between the center line of the corbel web and the axis of the tube, and the shortest perpendicular distance from the end of the corbel flange to the outer surface of the cylindrical tube. Step 4: Place the round tube column horizontally on the jig, and perform initial positioning of the bracket according to the arc length, included angle and vertical distance, and use temporary triangular supports to fix the upper and lower flange plates of the bracket; Step 5: After spot welding, measure the difference in arc length at the root of adjacent brackets. If the deviation is greater than the allowable value given in the drawing, loosen the spot weld and readjust. Step Six: Measure the diagonal length between the center of the ends of adjacent brackets in the upper and lower layers. If the difference between the measured value and the theoretical value on the drawing is greater than the allowable value given on the drawing, return to Step Four to readjust. Step 7: After completing the positioning of all brackets, proceed to the formal welding and perform formal welding according to the drawing requirements.

2. The method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket according to claim 1, characterized in that: In step one, the establishment of the quarter points is specifically as follows: Two mutually perpendicular planes passing through the center of the tube are projected onto the two ends and the outer surface of the cylindrical tube using a laser line projector. The planes intersect the tube wall to obtain four quarter points. The four points are connected to form a cross center line. The arc length between the four points is measured with a tape measure. If the difference in the diagonal arc length is ≤1mm, the benchmark is confirmed.

3. The method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket according to claim 1, characterized in that: It also includes an inner diaphragm. Using the lower tube end face as a reference, the inner diaphragm is positioned according to the axial distance indicated in the detailed drawing, and the distance from the outer ring of the inner diaphragm to the four radial lines of the cross center line is measured to ensure that the alignment error between the inner diaphragm and the subsequent bracket flange is ≤1mm.

4. The method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket according to claim 1, characterized in that: The temporary triangular support in step four is a steel strip of the same material with a thickness of t=16mm±1mm, a width of b=30mm±1mm, and a length of L=200mm±5mm. Both ends are beveled at 30° and spot-welded to the upper and lower flange plates and the pipe wall at a 45° angle to form a flange spacing retainer.

5. The method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket according to claim 4, characterized in that: After the temporary triangular support is removed, it is cleaned by carbon arc gouging or angle grinder. The repair welding uses E50 welding rods, and the repair welding length is ≥50mm. After the repair welding, it is ground flat.

6. The method for three-dimensional positioning and assembly of an irregularly shaped circular tube column bracket according to claim 1, characterized in that: In step seven, the formal welding sequence is to weld the lower layer first, then the upper layer, with symmetrical welding at 120° intervals.

7. A drawing annotation system for implementing the assembly method of any one of claims 1-6, characterized in that: It includes: The reference module is used to establish quarter points and form a cross center line on the end face or outer surface of a cylindrical tube. The arc length positioning module is used to mark the arc length of the starting point of the root of the cow leg and the difference in circumferential arc length between adjacent roots of the cow leg, with the quarter point as the starting point. The Spatial Angle-Vertical Distance module is used to mark the angle between the corbel web and the column axis, as well as the shortest vertical distance from the flange end to the outer surface of the column. The redundancy verification module is used to provide the theoretical diagonal length between the centers of the ends of adjacent corbels in the upper and lower layers in the additional area of ​​the drawing, for on-site measurement and comparison. All dimensions are arranged to the same scale as the 1:1 unfolded strip diagram of the outer surface of the circular tube, forming a single printable drawing medium.

8. The drawing annotation system according to claim 7, characterized in that: The theoretical length of the diagonal is extracted from the 3D model and written back into the remarks column of the drawing, forming a design-manufacturing closed-loop verification.

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