RU2246365C1 - Method for making welded structure with curvilinear surface - Google Patents

Abstract

FIELD: plastic working of metals.

SUBSTANCE: method for making welded structure with curvilinear surface having metallic sheets with parts welded to them comprises steps of shaping by successive or rotary application of local bending efforts during one or several transitions along surface area of structure; initially welding sheets one to other and welding parts arranged on sheet surface to said sheets; then performing formation of structure while by-passing welded joints and starting such motion of upper deforming member that it is to be in position being the nearest relative to welded parts in edges and ends of sheet; using pressure roller or punch as upper deforming member; using roller or double-support beam as lower deforming member; welding parts adjoined to curved surface of structure.

EFFECT: enhanced accuracy of preset curvilinear surfaces of structure, simplified manufacturing process due to reduced number of transitions.

4 cl, 3 dwg

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of welded structures in the metal industry.

Known and widely used are methods of manufacturing welded structures with a curved surface with initial shaping - flexible sheathing and kit parts (lock joints, fittings, stiffeners, overlays, etc.) and subsequent welding, as a rule, in stands and beds with the corresponding curved surface. After the welding operation, such structures require the elimination of the obtained welding deformations by bending on presses or by local heating (see Kuklin OS, Mikhailov BC, Shirshov IG Problems of improving the quality of manufacturing of hull structures. L., Shipbuilding, 1988) .

These traditional methods of manufacturing welded structures require a large amount of fitting and welding work performed on an uncomfortable curved surface with a high level of capital, energy and laborious processes.

In recent years, methods of locally sequential and rotational-local deformation of sheet parts have been developing, providing a significant reduction in both the deformation forces and the capital and energy intensity of processes (see Alexandrov V.L., Gorbach V.D., Kuklin O.S. ., Shabarshin VP High breakthrough technologies of bending and editing. - “Bulletin of shipbuilding technology”, 1998, No. 4).

An analogue of the proposed method can be considered a number of Russian patents issued for methods and devices for the indicated resource-saving technologies of forming, see, for example, patents: No. 2194887, 2194888 for sequential local deformation and patents No. 2102170, 2191082, 2194589 for rotational-local deformation.

The closest set of features to the claimed method is the patent No. 2199408 on "Method of forming bent sheet parts", which is taken as a prototype. This method consists in applying bending loads in one or more transitions over the area of the workpiece, and loads are applied locally sequentially or rotationally locally.

The disadvantage of this method of forming bent sheet parts is the possibility of its use only for shaping sheet parts, so welding of the entire structure using this method can only be done after the forming process, i.e. with a large amount of fitting and control assembly work and, therefore, with a high level of energy and labor intensity of the process.

The objective of the present invention is to reduce the complexity and resource saving in the manufacture of welded structures with a curved surface. The technical result, due to which this problem is solved, is to increase the accuracy of the specified curved surfaces of the structure while simplifying the process by reducing the number of transitions.

This result is achieved due to the fact that in the proposed method, the sheets of the structure are welded together and parts located on the surface of the sheets, and then the operation of applying local bending forces for one or more transitions on the surface of the welded structure by sequential or rotational shaping is performed. At the same time, shaping begins with the closest passage of the upper deforming element to the welded parts at the edges and at the ends of the sheet, and a pressure roller or punch is used as the upper deforming element, and a roller or double support beam as the lower one. As a result of applying the method with such a sequence of operations, there is no need to eliminate welding deformations after primary welding, since they are eliminated simultaneously with shaping. In addition, the beginning of shaping from parts located at the edges of the sheet provides the most complete bending of the edges and the welded parts protruding after bending do not interfere with subsequent shaping. At the end of the shaping, parts adjacent to the curved surface of the structure are installed and welded.

In the particular case of the proposed solution, the initial welding of the structure is performed in a position convenient for assembly and welding, for example, on a horizontal welding table.

In another particular solution, to increase the accuracy of obtaining the shape of a given curved surface, the axis of passage of bending forces from the upper deforming element should be from the nearest weld at a distance of not more than 5 thicknesses of the bent sheet. In this case, as shown by the conducted experimental studies at the AGPM-15M rotational-local bending installation (see Report on Research Institute of FSUE TsNIITS GKLI-3210-089-2002), edge bending and minimal impact on the weld are ensured and at the same time time, the influence of edge effects and welded parts on the accuracy of shaping is excluded.

In another particular case, the welded parts adjacent to the curved surface of the structure are welded after completion of the shaping of the structure and, when installed, serve as a template for controlling the shape of the curvature of the surface of the structure obtained after bending.

The invention is illustrated by drawings, which depict a diagram of the application of force and the type of welded sheet pile made according to the technical specifications TU 5264-001-39423320-2002:

Figure 1 is a cross section of the final shape of the fabricated structure;

Figure 2 is a diagram of the application of the initial bending force shaping after welding of the structure in a convenient horizontal position;

Figure 3 - diagram of the application of bending forces at the butt weld of the sheet metal.

A fully fabricated welded structure (Figure 1) consists of sheets 1 bent along the diameter D, welded parts in the form of elements of the castle joints 2 and 3, brackets 4, intersecting the curved surface of the structure in the form of a chord, and a fastening patch sheet 5. The welded parts are welded with sheets 1 of the fillet welds 6 and 7, and the sheets 1 are interconnected along the length of the butt weld 8 (Figure 3).

The manufacture of this welded structure according to the proposed method is carried out as follows: in a horizontal position convenient for welding, parts 2, 3, 5 are welded to the sheets 1 of thickness S joined together and welded together (Figure 2). Then, with the beginning of forming by the upper deforming element in the form of a roller 9, which is rolled with a bending force P on the surface of the sheets 1 at a distance of no more than 5S of its axis from the nearest weld 6 of the weldment 3, the first edge is bent to the required radius D / 2, then the roller is transferred to the other side of the workpiece in position 11 and the next edge of the structure is bent with the welded part 2. Then the roller is rolled along the surface of parts 5 and 1 from position 11 to position 9 and the structure is bent and in the central section, at the same time, at the butt weld 8 (FIG. 3) connecting the parts 1 in length, the roller is lifted above the sheet and the weld 8 and it passes idle from position 10 to position 12, avoiding direct pressure on the weld 8 After the final bending of the structure along a predetermined radius equal to D / 2, the brace 4 is welded, the width of which serves as a template for controlling the finally bent structure. Along with the flexible design, the resulting welding deformations are also eliminated.

Pilot testing according to the above technical conditions for manufacturing the design of a welded sheet pile with a diameter of 800 mm, including initial welding and elimination of welding deformations during the bending process, was carried out on a prototype of a pile made on a 1: 2 scale on an automated bending machine AGPM-15M rotational-local method of deformation with a force of 15 kN. In this case, in comparison with commonly used methods for the manufacture of such piles from a pipe billet or from a flat sheet, the following results were achieved:

- the complexity of the assembly was reduced by 3 times;

- the complexity of welding was reduced by 2-2.5 times;

- reduction of the energy intensity of the process by 2-4 times.

In general, taking into account the analysis, it was found that the complexity and cost of manufacturing the design decreased by about 3 times.

Claims (4)

1. A method of manufacturing a welded structure with a curved surface containing metal sheets and parts welded to them, including the application of local bending forces for one or more transitions over the area of the structure by sequential or rotational shaping, characterized in that the sheets are first welded together and the parts, located on the surface of the sheets, then carry out the shaping of the structure, bypassing the welds and starting with the closest passage of the upper defor iruyuschego element to the welded parts at the edges and at the ends of the sheet, thus deforming as the upper member using a pressure roller or a punch, and as the lower - a roller or doubly-supported beams then welded parts adjacent to the curved surface of the structure. 2. The method according to claim 1, characterized in that the initial welding of the structure is performed in a position convenient for assembly and welding, for example, in horizontal. 3. The method according to claim 1, characterized in that the axis of passage of bending forces from the upper deforming element is at a distance from the nearest weld at a distance of not more than 5 thicknesses of the bent sheet. 4. The method according to claim 1, characterized in that before welding the parts adjacent to the curved surface of the structure, they are used as a template for controlling a curved surface obtained as a result of shaping.

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