Method for controlling manufacturing precision of super-long T-shaped cross beam of steel truss girder

Abstract

The invention discloses a method for controlling the manufacturing precision of a super-long T-shaped cross beam of a steel truss girder, which comprises the following steps of: formulating a partitioning scheme, dividing a large cross beam into a plurality of sections of small cross beams, controlling the length of a single small cross beam not to exceed 9m, and arranging a butt-joint groove at the joint position of a web plate and a flange plate of each small cross beam; modeling and lofting are carried out, a web plate and a flange plate are sequentially taken out, a process adding amount is set on the bolt hole side of the small cross beam, and meanwhile the width adding amount of a U-rib notch is set; assembling a small cross beam web plate and a flange plate by taking the base line as a reference, and determining an assembling precision control target; and designing an overall assembly scheme of the large cross beam, optimizing a structure welding sequence, formulating pre-arching process parameters, and finally realizing a precision control target. The method is not influenced by the length rolling capacity of the steel plate, can adapt to machining precision control of the orthogonal special-shaped plate in the steel structure bridge, has universality, is generally used in various steel structure machining factories, is high in precision after being manufactured, reduces a large amount of repair work, and can obviously improve the construction efficiency.

Description

Technical Field

[0001] The invention relates to a method for controlling the manufacturing accuracy of a T-shaped crossbeam, and in particular to a method for controlling the manufacturing accuracy of an ultra-long T-shaped crossbeam of a steel truss. Background Art

[0002] At present, the traffic volume of many operating highways is gradually becoming saturated, and even frequent congestion problems will occur. Therefore, in order to meet the current growing traffic demand, the reconstruction and expansion of highways has become an important development need for highway transportation construction. Steel bridge structures are widely used in bridges of various spans because of their relatively light weight, high material strength, and convenient construction. In particular, steel truss bridges are composed of truss rods, which have small rod sizes, convenient transportation, fast erection speed, little impact on navigation, and better stress state. Therefore, steel structure bridges have gradually been promoted and applied in highway reconstruction and expansion projects, and there is also a relatively large demand for large-span simply supported steel truss bridges with excellent mechanical properties, convenient erection, strong seismic resistance, and good driving comfort.

[0003] With the continuous development of steel truss bridges, the width of the bridge deck has increased significantly from two lanes to four lanes. Due to the special geographical location and the size restrictions on road transportation, the bridge deck and beams need to be shipped to the bridge site separately. How to ensure the installation accuracy of the bridge deck U ribs and beam notches during the erection process has brought great troubles to the current process. At present, large steel trusses are transported by ship, and can be made into large sections or bridge deck blocks in the factory and shipped to the site for overall installation. Since the beams and bridge decks have been assembled into a whole in the factory in advance, there is no problem of matching the accuracy of the beams to the bridge decks in the above two solutions. However, for the increasing number of steel trusses with small and medium spans in the current highway reconstruction and expansion, they are also restricted by the size of road transportation. The process of making them into bridge deck blocks is obviously no longer applicable. At the same time, the larger the size, the greater the transportation risk, and the corresponding cost is also increasing. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a method for controlling the manufacturing accuracy of an extra-long T-shaped crossbeam of a steel truss, which is not affected by the length of the steel plate and has high manufacturing accuracy.

[0005] Technical solution: The present invention comprises the following steps:

[0006] S1. Develop a block division plan to divide the large beam into multiple small beams, control the length of a single small beam to not exceed 9m, and set a butt groove at the joint between the web and flange of the small beam;

[0007] S2. Modeling and lofting, lower the web and flange plates of the small crossbeam in sequence, set the process addition on the bolt hole side of the small crossbeam, and set the width addition of the U-rib notch;

[0008] S3. Assemble the web and flange plates of the small cross beam based on the baseline, and position and assemble the stiffening ribs based on the reference end and the inner skin of the flange plate, and clarify the assembly accuracy control target;

[0009] S4. Assemble the large beam as a whole, optimize the structural welding sequence, formulate pre-arch process parameters, and control the bolt hole group accuracy.

[0010] The large cross beam comprises a web and a flange plate, wherein the flange plate is arranged at the bottom of the web, a plurality of U-rib notches are arranged at intervals on the top of the web, bolt hole groups are arranged on both sides of the web, and stiffening ribs are arranged on the sides of the web.

[0011] During modeling, the large beam is divided into multiple sections according to the block scheme in the model.

[0012] The web of the small crossbeam is cut out by CNC cutting equipment, and the web is precisely marked with vertical baselines and groove matching tangent lines, and the groove is connected by a semi-automatic trolley flame cutting.

[0013] The flange plate of the small cross beam is machine-cut by gate cutting equipment, and the butt-jointed groove is flame-cut by a semi-automatic trolley.

[0014] The method of assembling the web and flange plates of the small crossbeam based on the baseline is specifically as follows: on the tire frame, the long center line of the flange plate is used as the standard, the baselines of the web and flange plates are aligned and positioned to assemble the small crossbeam T-shape, and during assembly, the groove of the bottom plate of the flange plate faces the non-crossbeam side.

[0015] The assembly precision control targets are specifically as follows: controlling the transverse flatness of the web to be ≤2.0mm, the longitudinal flatness to be ≤3.0mm, the verticality of the stiffening rib to be ≤1.0mm, and the lateral deflection to be ≤3.0mm.

[0016] The pre-arch process parameters are as follows: laying a small T-shaped crossbeam on the tire frame, and positioning and assembling it based on the baseline; during assembly, the middle small crossbeam is pre-lifted 15-18mm toward the U-rib notch side as a whole, the end positions of the small crossbeams on both sides remain unchanged, and the butt ends are slightly adjusted to ensure that the butt flange plate edges are flush and the misalignment is ≯0.5mm.

[0017] The welding sequence is: first symmetrically weld the crossbeam web butt seam, then symmetrically weld the flange plate butt seam, and after welding, correct the web flatness and stiffening rib verticality, the web transverse flatness ≤1.0mm / m, and the stiffening rib verticality ≤1.0mm.

[0018] The precision control of the bolt hole group is specifically as follows: based on the horizontal baseline and the vertical baseline, the process addition for the upper opening of the bolt hole group on both sides of the beam is set, the lower opening is controlled according to the design size, no process quantity is set, the web drilling opposite line is marked, and the matching tangents at both ends of the web of the beam are simultaneously marked, the two ends of the beam are matched and cut according to the matching tangents, the flame-cut parts are scraped and ground, and finally the template is clamped and a magnetic drill is used to accurately drill holes.

[0019] Beneficial effects: The present invention is not affected by the steel plant's steel plate length rolling capacity, and can adapt to the processing accuracy control of orthogonal special-shaped plates in steel structure bridges. The processing equipment such as cutting and welding of the present invention is universal and can be used in various steel structure processing plants. The present invention has high precision after production, reduces a large amount of rework work, and can significantly improve construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the crossbeam structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the crossbeam blocks of the present invention;

[0022] Figure 3 This is the cutting diagram of the web of the small crossbeam after the increase in weight;

[0023] Figure 4 This is the U-rib notch cutting pattern drawing;

[0024] Figure 5 This is a schematic diagram of the small beam assembly;

[0025] Figure 6 This is a schematic diagram of marking and drilling. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings.

[0027] The method for controlling the manufacturing accuracy of the super-long T-shaped cross beam of the steel truss of the present invention comprises the following steps:

[0028] S1. Develop a block division plan. To ensure the best precision of the CNC blanking equipment, combined with previous blanking precision control experience, the large beam is divided into multiple small beams, and the length of a single small beam is controlled not to exceed 9m. A butt groove is set at the joint between the web and flange of the small beam. The large beam includes a web 1 and a flange 2. The flange 2 is set at the bottom of the web 1. A plurality of U-rib notches 5 are set at intervals on the top of the web 1. Bolt hole groups 4 are set on both sides of the web 1, and stiffening ribs 3 are set on the side of the web 1.

[0029] S2. Use TEKLA modeling software to build a model at a 1:1 ratio, and simultaneously divide the large beam into multiple sections in the model according to the block plan. Export the beam web cutting file from TEKLA, set the process addition on the bolt hole side of the small beam, and set the width addition of the U-rib notch on the beam. Then use CNC cutting equipment to accurately cut out the web of the small beam, and accurately mark the web, mark the vertical baseline of the web, and the tangent line of the groove, and use a semi-automatic trolley to flame cut the butt groove; use a gate cutting machine to accurately cut out the flange plate, and use a semi-automatic trolley to flame cut the butt groove.

[0030] S3. Assemble the web and flange plates of the small crossbeam based on the baseline, and clarify the assembly accuracy control target. On the tire frame, align the web and flange baselines with the center line of the flange plate in the long direction to assemble the small crossbeam T-shape. When assembling, pay attention to the groove of the bottom plate of the flange plate facing the non-crossbeam side. Use the reference end and the inner skin of the flange plate as the reference to position and assemble the stiffening ribs. After checking that the assembly dimensions are correct, weld and trim them, focusing on controlling the transverse flatness of the web ≤2.0mm, the longitudinal flatness ≤3.0mm, the verticality of the stiffening rib ≤1.0mm, and the lateral bend ≤3.0mm.

[0031] S4. Lay the small crossbeam T-shaped on the tire frame and position and assemble it based on the baseline. During assembly, the middle small crossbeam is pre-lifted 15-18mm toward the U-rib notch side as a whole. The small crossbeams on both sides keep the end positions unchanged. Fine-tune the butt ends to ensure that the butt flange plate edges are flush and the misalignment is ≯0.5mm. After checking that the assembly dimensions are correct, weld. Pay attention to strictly follow the welding sequence during welding. First, symmetrically weld the web butt seam of the crossbeam, and then symmetrically weld the flange plate butt weld. After welding, correct the web flatness and stiffening rib verticality. The web transverse flatness is ≤1.0mm / m, and the stiffening rib verticality is ≤1.0mm. Based on the horizontal baseline and vertical baseline, set the upper process addition of the bolt hole group on both sides of the crossbeam. The lower end is controlled according to the design size without setting the process quantity. Draw the web drilling opposite line, and simultaneously draw the tangent lines at both ends of the web of the crossbeam. Cut both ends of the beam according to the matching tangent line, grind and trim the flame-cut parts, and finally use a magnetic drill to accurately drill holes on the template.

[0032] Example

[0033] The method for controlling the manufacturing accuracy of the super-long T-shaped cross beam of the steel truss beam of this embodiment comprises the following steps:

[0034] Step 1. Develop a block division plan. In order to ensure the best precision of the CNC blanking equipment, combined with previous experience in blanking precision control, the large beam is divided into 3 small beams. For details, see Figure 2 , control the length of a single small beam to about 8 meters, and set a butt groove at the joint between the web and flange of the small beam. Figure 1 As shown, the large beam includes a web 1 and a flange 2. The flange 2 is arranged at the bottom of the web 1. A plurality of U-rib notches 5 are arranged at intervals on the top of the web 1. Bolt hole groups 4 are arranged on both sides of the web 1. Stiffening ribs 3 are arranged on the side of the web 1. The large beam is divided into three small beams, including a first small beam 11, a second small beam 12 and a third small beam 13. Figure 5 shown.

[0035] Step 2. Use TEKLA modeling software to build a model at a 1:1 ratio. In the model, divide the large beam into three sections according to the block plan. Export the web blanking file of the beam from TEKLA, and set a +10mm process addition on the bolt hole side of the small beam. Figure 3To set the web blanking procedure after adding quantity, set the width of the U-rib notch on the beam to 4mm. Figure 4 As shown, CNC cutting equipment is then used to accurately cut out the web of the small crossbeam, and precise lines are drawn on the web, the vertical baseline of the web and the tangent line of the groove are drawn, and a semi-automatic trolley is used to flame cut the butt groove; a gate cutting device is used to accurately cut out the flange plate, and a semi-automatic trolley is used to flame cut the butt groove.

[0036] Step 3. Assemble the web and flange plates of the small crossbeam based on the baseline, and clarify the assembly accuracy control target. On the tire frame, align the web and flange baselines with the center line of the flange plate in the long direction to assemble the small crossbeam T-shape. When assembling, pay attention to the groove of the bottom plate of the flange plate facing the non-crossbeam side. Use the reference end and the inner skin of the flange plate as the reference to position and assemble the stiffening ribs. After checking that the assembly dimensions are correct, weld and trim, focusing on controlling the transverse flatness of the web ≤2.0mm, the longitudinal flatness ≤3.0mm, the verticality of the stiffening rib ≤1.0mm, and the lateral bend ≤3.0mm.

[0037] Step 4. Lay three small T-shaped beams on the tire frame and press Figure 5 Use the baseline as the reference for positioning and assembly. During assembly, the second small beam 12 is pre-lifted 15mm toward the U-rib groove side as a whole. The first small beam 11 and the third small beam 13 keep the end positions unchanged. Fine-tune the butt ends to ensure that the butt flange plate edges are flush and the misalignment is ≯0.5mm. After checking that the assembly dimensions are correct, weld. Pay attention to strictly follow the welding sequence during welding. First, symmetrically weld the web butt seams of the beams, and then symmetrically weld the flange butt welds. After welding, correct the web flatness and the verticality of the stiffening ribs. The transverse flatness of the web is ≤1.0mm / m, and the verticality of the stiffening ribs is ≤1.0mm. Using the horizontal baseline m and the vertical baseline n as the reference, set the process addition for the upper opening of the bolt hole group on both sides of the beam. The lower opening is controlled according to the design dimensions, and no process addition is set. For details, see Figure 6 , mark the web drilling line, and simultaneously mark the tangent lines at both ends of the beam web. Cut the two ends of the beam according to the tangent lines, grind and trim the flame-cut parts, and finally use a magnetic drill to accurately drill holes on the template.

Claims

1. A method for controlling the manufacturing accuracy of an ultra-long T-shaped crossbeam of a steel truss, characterized in that: The following steps are involved: S1. Develop a block division plan to divide the large beam into multiple small beams, control the length of a single small beam to not exceed 9m, and set a butt groove at the joint between the web and flange of the small beam; S2. Modeling and lofting, lower the web and flange plates of the small crossbeam in sequence, set the process addition on the bolt hole side of the small crossbeam, and set the width addition of the U-rib notch; S3. Assemble the web and flange plates of the small cross beam based on the baseline, and position and assemble the stiffening ribs based on the reference end and the inner skin of the flange plate, and clarify the assembly accuracy control target; S4. Assemble the large beam as a whole, optimize the structural welding sequence, formulate pre-arch process parameters, and control the bolt hole group accuracy.

2. The method for controlling the manufacturing accuracy of an ultra-long T-shaped crossbeam of a steel truss according to claim 1, characterized in that: The large cross beam comprises a web and a flange plate, wherein the flange plate is arranged at the bottom of the web, a plurality of U-rib notches are arranged at intervals on the top of the web, bolt hole groups are arranged on both sides of the web, and stiffening ribs are arranged on the sides of the web.

3. The method for controlling the manufacturing accuracy of an ultra-long T-shaped crossbeam of a steel truss according to claim 1, characterized in that: During modeling, the large beam is divided into multiple sections according to the block scheme in the model.

4. The method for controlling the manufacturing accuracy of an ultra-long T-shaped crossbeam of a steel truss according to claim 1, characterized in that: The web of the small crossbeam is cut out by CNC cutting equipment, and the vertical baseline of the web and the groove matching tangent line are marked on the web, and the groove is flame cut.

5. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 4, characterized in that: The flange plate of the small crossbeam is machine-cut by gate cutting equipment, and the butt groove is flame-cut.

6. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 5, characterized in that: The method of assembling the web and flange plates of the small crossbeam based on the baseline is specifically as follows: on the tire frame, the long center line of the flange plate is used as the standard, the baselines of the web and flange plates are aligned and positioned to assemble the small crossbeam T-shape, and during assembly, the groove of the bottom plate of the flange plate faces the non-crossbeam side.

7. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 6, characterized in that: The assembly precision control targets are specifically as follows: controlling the transverse flatness of the web to be ≤2.0mm, the longitudinal flatness to be ≤3.0mm, the verticality of the stiffening rib to be ≤1.0mm, and the lateral deflection to be ≤3.0mm.

8. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 7, characterized in that: The pre-arch process parameters are as follows: laying a small T-shaped beam on the tire frame, and positioning and assembling it based on the baseline; during assembly, the middle small beam is pre-lifted 15-18mm toward the U-rib notch side as a whole, the end positions of the small beams on both sides remain unchanged, and the butt ends are fine-tuned to ensure that the butt flange plate edges are flush and the misalignment is ≯0.5mm.

9. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 8, characterized in that: The welding sequence is: first symmetrically weld the crossbeam web butt seam, then symmetrically weld the flange plate butt seam, and after welding, correct the web flatness and stiffening rib verticality, the web transverse flatness ≤1.0mm / m, and the stiffening rib verticality ≤1.0mm.

10. The method for controlling the manufacturing accuracy of an ultra-long T-shaped cross beam of a steel truss according to claim 9, characterized in that: The precision control of the bolt hole group is specifically as follows: based on the horizontal baseline and the vertical baseline, the upper process addition of the bolt hole group on both sides of the beam is set, the lower opening is controlled according to the design size, no process quantity is set, the web drilling opposite line is marked, and the matching tangents at both ends of the web of the beam are marked simultaneously, the two ends of the beam are cut according to the matching tangents, the flame-cut parts are trimmed, and finally the template is clamped and holes are drilled.

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