CN1121129A - Production technology of bridge arch rib with elliptical steel-tube structure - Google Patents

Abstract

The prodn techn features its two-step bending of single section of steel tube. The steel tube is heated locally and successively at 600-850 deg.C and the cooling shrinkage produces concave arch. The convex arch of steel tube is formed through mechanical moulding bending. Using the said prodn techn, the wall thickness, the strength, the rigidity of steel tube are constantly maintained, and produced bent arch is accurate and smooth and thus the bent tubes can assemble smooth bridge arch rib.

Description

The manufacture craft of bridge arch rib with elliptical steel-tube structure

The invention belongs to bridge arch rib steel tubular structure structure manufacture technical field.

Design at present and the bridge arch rib form of structure of building have circle, hyperbola, parabola shaped etc., and the section configuration of arch rib has circle, Double Circle, oval peaceful ellipse etc.The different curves of these arch ribs all are spliced by the single-unit steel pipe, if the single-unit steel pipe does not carry out bending, then the whole piece arch rib is exactly the broken line arch rib, and is not slick and sly.Be to adopt flame heat to the single-unit steel tube bending now, reduce the ultimate strength of steel, improve its plasticity and ductility, prepare certain external force again, make it stretch bending and be shaped, this method makes steel pipe that overheated and burning takes place easily, makes the decarburization of steel oxidation scaling loss, thickness of steel pipe subtracts book, and the strength and stiffness of reduction steel pipe perhaps cause cold working, make the steel sclerosis, the plasticity and the toughness of steel pipe have been reduced, the bending of more inapplicable thick walled steel tube.

The purpose of this invention is to provide a kind of flat oval thick walled steel tube, to be bent into radian accurate, slick and sly and do not change steel tube performance and wall thickness, promptly different position and orders heats on the recessed arch face of steel pipe, the compound shrinkage stress in cooling back and add different mechanical pressures and reach heavy wall flat oval steel pipe slyness and bend to different radians, thus make whole piece bridge arch rib slyness.

The present invention is the technology of making a kind of bridge arch rib of flat oval steel tubular structure, the whole piece arch rib is spliced by the single-unit steel pipe, the length of single-unit steel pipe is 2.5～3.0 meters, and wall thickness is 20 millimeters, and the section configuration of steel pipe is a flat oval shape, it is of a size of 800 * 2000 millimeters, minor axis has the flat face of 1200 mm wides to two ends, and major axis is to the R=400 millimeter, and the single-unit steel pipe is the steel plate by 20 millimeters thick, after leveling reaches (CJJ2-90 standard criterion), roll and be welded.Bending steel pipe adopted for two steps carried out; At first bend recessed arch face, indeformable for the transverse strength and the circular arc that improve steel pipe, before bending, add three semielliptical horizontal strength plates of weldering at recessed arch face inwall, the strength plate hight is 75 millimeters, wide is 20 millimeters, the position of strength plate; Article one,, locates (after treating that steel tube bending is good, add weldering three semiellipse strength plates in addition again, be combined into three circle hoop strength plates) far from 100～150 millimeters of terminations at steel pipe two for other two at the center of steel pipe length.Standardized longitudinal centre line on the recessed arch face of steel pipe, at standardized cross central line of the mid point of longitudinal centre line, the plain line of its two ends and major axis ragged edge intersects vertically, with this joining is the summit of isosceles triangle, draw two symmetrical isosceles triangles, draw at flat face and the tangent place of arc surface on its base, and bottom side length is 120～150 millimeters (looking the decision of steel pipe length).Cross central line both sides (symmetry) are the same summit of isosceles triangle on one side every the distance of three times of left and right sides isosceles triangle bottom side lengths, draw several to foregoing symmetrical isosceles triangle, with the longitudinal centre line is standardized connecting band in a pair of base to symmetrical isosceles triangle of symmetry, the bottom side length of its bandwidth ratio isosceles triangle is smaller, adjust (seeing shown in Figure 3) after being convenient to.To recessed arch face heating position and order; Heating and temperature control is at 600 ℃～850 ℃, i.e. heating makes the steel surface color be dark cherry red or cherry red gets final product.At first a pair of symmetrical isosceles triangle to cross central line two heats simultaneously, after reaching said temperature, again to heat simultaneously near the symmetrical isosceles triangle on cross central line both sides reach said temperature after, progressively heated up to all isosceles triangles again to the symmetry isosceles triangle heating of steel pipe two, again the isosceles triangle base connecting band that cross central line connected is heated, its temperature also is to be controlled at aforesaid temperature, then to second pair of connecting band heating, progressively, all heated up to all connecting bands to the connecting band heating at two.Camber appears in the recessed arch face of cooling back steel pipe, but its curvature and circular arc degree, also must heat and adjust, at first adjust the width of heating connecting band, again from the circular arc at steel pipe two ends and flat face intersection to transverse center one termination (on the plain line), draw four heating N lines, draw four N1 heater wires and above-mentioned four heating N line parallels again from steel pipe two 1/4th, these eight heater wires are all in recessed arch face both sides, the heating direction heats to the centre from steel pipe two, width is controlled at (see figure 3) between 60～100 millimeters, so heated in sequence cooling compound contraction in back, recessed arch just appears in the recessed arch face of steel pipe, and its recessed camber and circular arc smoothness can reach the curvature and the slyness of the recessed arch face of steel pipe by the width of regulating heating triangle base connecting band, and can not twist.After the recessed arch face of steel pipe bends, bend protruding arch face again, bend protruding arch face and adopt mechanical die forming, its equipment is made up of upper and lower mould, mould bases, oil pressure pump and jack; Patrix is fixed on the mould bases; mould bases has four root posts; next two is vertical columns; two of fronts are active column (can turn down); counterdie is bearing on four guide upright posts; four jack are arranged below the counterdie; head on counterdie; below four jack adjusting pad is arranged; by adjusting pad be placed on four jack on the mould bases base girder steel oil pipe line series connection and with the oil pipe line UNICOM of the electronic pressure testing oil pump of SY600, oil pipe line is made with heavy seamless steel pipe, the lower end of vertical columns and guide upright post all is fixed on the mould bases base girder steel; the lower end of movable principal post and base girder steel are by the pivot pin loose joint, and the upper end also is by pivot pin and patrix loose joint.When bending, steel pipe is inserted in patrix (the protruding arch face of steel pipe down), two active columns are holded up, the upper end is locked on the patrix with pivot pin, mixes up the position, starts the electronic pressure testing oil pump of SY600, four jack synchronously with counterdie along four guide upright posts to rising, the protruding arch face of steel pipe that is bent is pressed between upper and lower mould, and according to the different requirements of the radian that is bent, the pressure that can control the electronic pressure testing oil pump of SY600 reaches.Whole piece parabola bridge arch rib, as long as radian requirement to the single-unit tube bending is different, but is more or less the same, so one pair of mould, suitable its pressure of control just can all single-unit steel pipes of arch rib have been bent, as long as can obtain the differently curved radian of steel pipe.The protruding arch face of steel pipe crooked good after, three semiellipse strength plates that connect three semiellipse strength plates and recessed arch face inwall in the protruding arch face inwall welding of steel pipe connect into three hoop strength plates again, so far the single-unit steel pipe has just bent.

The advantage of car invention, accurately slick and sly by the steel pipe radian that above-mentioned technology bends, the wall thickness of steel pipe does not subtract book (because of not stretching), guarantees that the intensity and toughness of steel pipe and other performances are constant.Present device is simple, and technology realizes easily, and the crooked radian of concavo-convex arch face is grasped easily, and the cross dimensions of steel pipe is constant, major axis to circular arc do not wrinkle and do not fall into, guarantee that whole piece bridge arch rib slyness is smooth.

Description of drawings, accompanying drawing 1 are the profiles of single-unit steel pipe, and it is a flat oval shape, are rolled by the steel plate of 20 millimeters thick to be welded, and 1 is recessed arch face among the figure, the 2nd, and protruding arch face, the 3rd, the hoop strength plate and the tube wall of steel pipe inwall are welded to connect.

Accompanying drawing 2 is longitudinal sectional views of single-unit steel pipe, and 1 is recessed arch face (not bending) among the figure, the 2nd, and protruding arch face (not bending), the 3rd, hoop strength plate.

Accompanying drawing 3 is that the single-unit steel pipe is subjected to recessed arch face heating position arrangement diagram, 4 is longitudinal centre lines on the recessed arch face among the figure, the 5th, the cross central line on the recessed arch face, the 6th, the plain line of major axis ragged edge, isosceles triangle, connecting band and N, N1 heater wire all are the position and the directions of heating among the figure, and the order of heating as previously mentioned.

Accompanying drawing 4 is longitudinal sectional views of the protruding arch face device of compacting, 8 is active columns among the figure, its lower end is connected by pivot pin 23 with base beam 22, its upper end flexibly connects by pivot pin and patrix 11, the 9th, mould bases platform steel plate, base beam 22 is arranged above it, the 12nd, counterdie, be contained on four guide upright posts 19, there are four jack 20 to withstand below the counterdie 12, have below the jack 20 and adjust cushion block 21 pads between jack 20 and base beam 22, oil pipe line 14 series connection of four jack 20, and and 16 Motordriven pressure test pump SY600 oil pipe lines, 15 UNICOMs, oil pipe line all adopts the seamless steel pipe of thickening to make, the 17th, the leg of active column 8, the 13rd, vertical columns, its lower end and base beam 22 affixed upper ends and patrix 11 are affixed, the 7th, guide runner, on guide upright post 19, counterdie 12 can move up and down along four guide upright posts 19 under the effect of jack 20, and the 10th, downtrodden steel pipe (workpiece).

Accompanying drawing 5 is transverse sectional view of the protruding arch face device of compacting steel pipe, 11 is patrixes among the figure, the 12nd, counterdie, the 19th, guide upright post, the 7th, guide pad, the 20th, jack (having four) withstands counterdie 12, and the cushion block 21 of adjustment is arranged between jack 20 and the base beam 22,14 is oil pipe line 15 UNICOMs of the series connection oil pipe line and the Motordriven pressure test pump 16 of four jack 20, the 18th, and the support of putting more energy into of guide upright post 19.

Embodiment makes a parabola shaped bridge arch rib according to above-mentioned technology, and the span of arch rib is 79.76 meters, sagitta is 15.952 meters, the section of arch rib is a flat oval shape, and it is of a size of 800 * 2000 millimeters, and major axis is to the R=400 millimeter, single-unit steel pipe length is 2,6 meters, 20 millimeters of wall thickness, whole piece arch rib different curvature is divided into 10 kinds, after adopting this technology segmentation bending shaping to the single-unit steel pipe, carry out assembly unit again and finish the whole piece bridge arch rib.The single-unit steel tube bending carries out in two steps, at first curved recessed arch face, its process using part and heated in sequence, cooling is shunk and is made the recessed arch face bending of steel pipe, curvature that it bends and slick and sly degree add the width of connecting band of thermal tracking isosceles triangle and (as shown in Figure 3) width from two of the arc sections of recessed arch face side to the centre that heat N, N1 line to reach the slick and sly and curvature requirement of recessed arch face by adjusting.Before bending recessed arch face, must add three semielliptical horizontal strength plates at the recessed arch face inwall of steel pipe, after recessed arch face bends, again steel pipe is placed on the molding apparatus, bends protruding arch face, because of upper and lower mould is arranged, so the radian of compacting is slick and sly certainly, but its curvature will bend pressure and resilience is controlled by adjustings, and protruding arch face is curved good, then the single-unit steel pipe has just bent, and then adds that at protruding arch face inwall other three semiellipse hoop strength plates are connected with three semiellipse strength plates of recessed arch face inwall.The single-unit steel pipe is spliced into the whole piece bridge arch rib then.

Claims (3)

1, a kind of manufacture craft of bridge arch rib with elliptical steel-tube structure, the whole piece arch rib is spliced by the single-unit steel pipe, to bending of single-unit steel pipe is to adopt flame heat, reduce the ultimate strength of steel, improve its plasticity and ductility and be equipped with certain external force, make it stretch bending and be shaped, the invention is characterized in, bend the single-unit steel pipe and adopted for two steps carried out, at first bend recessed arch face; On recessed arch face, draw the position and the area of good heating, be symmetrical isosceles triangle and triangle base connecting band and N, N1 heater wire, symmetrical isosceles triangle in the middle of heating earlier, heat connecting band and N, N1 heater wire again, heating and temperature control is at 600 ℃～850 ℃, and cooling is shunk and met the requirements of recessed arching rate and slick and sly degree, before the heating, at three semielliptical hoop strength plates of the recessed arch face inwall welding of steel pipe, bending of protruding arch face adopted mechanical die forming.

2, the manufacture craft of a kind of bridge arch rib with elliptical steel-tube structure according to claim 1, it is characterized in that, the summit of the isosceles triangle of heating is on the plain line of major axis ragged edge, the base is positioned at flat face and the tangent place of arc surface, 120～150 millimeters of bottom side lengths, same triangle edge vertex distance is the bottom side length of three times of isosceles triangles, connect the bottom side length that bandwidth is slightly less than isosceles triangle, N, the N1 heater wire is controlled at 60～100 mm wides, the heating sequence middle symmetrical isosceles triangle of the recessed arch face of heating steel pipe earlier progressively heats isosceles triangle to two, connecting band to the centre heats then, again to N, N1 line heating, its direction from two to the centre.

3, the manufacture craft of a kind of bridge arch rib with elliptical steel-tube structure according to claim 1, it is characterized in that, managing protruding arch face bends and adopts mechanical mold pressing to finish, its equipment is fixed on the mould bases by patrix (11), counterdie (12) can rise or descend along guide upright post (19), there are four jack (20) to withstand below the counterdie (12), jack (20) is placed on the base beam (22) by adjusting cushion block (21), oil pipe line (15) UNICOM of the oil pipe line (14) of four jack (20) and Motordriven pressure test pump (16), steel pipe is inserted in the protruding arch face of patrix (11) between upper and lower mould, hold up active column (8), start Motordriven pressure test pump (16), jack (20) is shaped the protruding arch face of compacting on counterdie (12) top.

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