RU2376094C1 - Method of shaping of box-like and tubular parts of double curvature - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metal deformation process, particularly to methods of bending and finishing of bended flat-pattern parts and can be used in different branches of mechanical engineering and construction during the manufacturing of box-like and tubular parts. At the first pass it is implemented shaping by means of mandrel with receiving of required necking of blank section, at the second pass it is implemented bending of blank by generatrix of detail, starting from its edges, and then by middle line of part. At the third pass there are removed unavoidable at the first and the second pass undesirable warpings of part ensured by changing of pressure-bearing and bearing deformation element, approximating radius of pressure-bearing element to specified radius in cross direction of part.

EFFECT: there are extended process capabilities, provided reduction of material- and energy intensity of bending prociesses.

2 dwg, 1 tbl

Description

The invention relates to the processing of metals by pressure, and in particular to methods of bending and finishing of bent sheet parts, and can be used in various industries of engineering and construction in the manufacture of box and tubular parts.

In recent years, methods have been developed for bending sheet metal parts of various shapes by rotational local deformation (RLD) methods using deforming elements made in the form of an upper pressure roller and a lower element in the form of a drive roller or matrix. Most of these technical solutions were created as a result of a complex of fundamental and applied research carried out under the federal target programs. Patents of the Russian Federation No. 2019337, 2102170, 2129929, 21911082, 2199440, 2194589, 2199408, 2200039 are analogues of the invention.

Closest to the claimed technical solution is a method of forming sheet metal parts of double curvature according to the patent of the Russian Federation No. 2243843, which is adopted as a prototype.

In the prototype, the method of forming parts of double curvature includes shaping the workpiece in two transitions. At the first transition, a curvature of a cylindrical or conical shape in the transverse direction of the workpiece is created without thinning and with a bend of one third of the specified curvature of the part in the same direction. In this case, the curvature at the first transition is given on rotary bending machines - rollers or on presses in universal dies for cylindrical bending. At the second transition, subsequent deformation is performed in the perpendicular direction with respect to the direction of deformation at the first transition and with the thinning of the workpiece by the method of rotational-local or sequentially-local deformation. At these transitions, the upper deforming element is selected with a curvature less than that specified in the transverse and longitudinal directions, at least by the amount of spring.

However, the use of two types of equipment reduces the efficiency of the bending process and increases its material and energy consumption.

The objective of the present invention is to expand the technological processes of RLD and to provide a significant reduction in material and energy consumption of bending processes.

The technical result, due to which this problem is solved, is to minimize the required shaping efforts.

The specified result is achieved using a combination of features available in the formula of the invention. At the same time, it is provided on one type of equipment for complex box-shaped and / or tubular parts.

In the proposed method, at the first transition, forming is carried out by rolling to obtain the required thinning of the workpiece sections, at the second transition, the workpiece is bent along the generatrix of the part, starting from its edges, and then along the midline of the part. At the third transition, the unwanted distortions of the part that are unavoidable during the first and second transitions are eliminated by changing the pressure and support deforming elements, bringing the radius of the pressure element closer to the specified radius in the transverse direction of the part.

The essence of the invention is illustrated by two drawings:

- figure 1 - shaping box parts at the first transition using rolling;

- figure 2 - shaping parts on the second and third transitions;

, а затем следует более быстрое падение до Δs=0.At the first transition, the shaping of the tubular part 1 of double curvature of thickness s (Fig. 1) in the longitudinal direction with the radius of the working surface R _{pr of a} given section begins with rolling by the pressure roller 2 on the prismatic insert of the matrix 3 along the surface 4 of the workpiece (indicated by a dashed line). In this case, the greatest thinning Δs are created at the places of the billet of curvature 5 and in its average section 6, and the billet receives some side curvatures at position 7. The value of the thinning Δs along the deformation line of the billet section of the billet of curvature of length lΔs changes according to the law of the circle. For example, the largest value of thinning Δs is halved over the length

and then follows a more rapid fall to Δs = 0.

At the second transition, the workpiece is bent to a given shape 8 to a given radius R _pop in the transverse direction (Fig. 2) by the upper roller 2 along an unfolded prismatic matrix 3.

At the third transition, the workpiece is brought to the desired shape and side deformations from the first and second transitions are eliminated, and both rolling (Fig. 1) and bending (Fig. 2) can be used. At the same time, changing the pressure elements (rollers 2) and turning the supporting elements (matrix 3), approximate the radius of the pressure element R _n to the specified radius of the part in the transverse direction R _pop (figure 2).

In general, the RLD methods are most fully tested on the multifunctional bending machine MGPS-25 in the production conditions of OJSC Almaz SF in the manufacture of sheet metal parts of complex shape, including of double curvature, on many ship orders, as well as the manufacture of several hundred cabins of drivers of new electric trains.

The application of the proposed method is expected at the orders of FSUE NPP Compensator in the production conditions of Almaz Marine Plant OJSC on the MGPS-25M multifunctional bending and straightening machine in the manufacture of a standard series of special protective couplings for pipelines from 188 to 1260 mm in diameter with a wall thickness of 8- 18 mm

Comparison of technical and economic indicators of the formation of box-shaped couplings by methods of rotational-local deformation (RLD), as proposed in the present invention, on the above MGPS-25M machine with a force of 25 tf and other methods is shown in the attached table, from which it follows that the method reduces the metal consumption of equipment 2-40 times depending on the size of the workpiece.

Comparative indicators of the formation of half couplings P6 (TU 1469-001-01297858-01) by various methods Indicators Hot stamping from a sheet (T ° -1000 ° C) Cold stamping Cold bending sheet Cold bending from a sheet with local heating (T ° 550-800 ° C) Punching from a sheet in sand or water Hydraulic stamping from a pipe Pipe Roller Under the press Freezing water Thinning of the workpiece,% > 20 /> 10 20/10 5/2 8/3 > 20 /> 8 > 20 /> 10 18/5 <20 / <10 Press force, tf 500/2000 1500/5000 400/400 400/400 - - - 100/1000 Mass of forming equipment, t 90/350 200/600 80/80 80/80 - 100/500 - 30/300 Tooling weight per standard size series of coupling halves, t 200 400 twenty twenty 150 10 <10 <5 Installed power (without thermal furnaces and other auxiliary equipment), kW 100/400 150/900 80/80 80/80 120/600 20/200 Piece time, n / h (for two half couplings) incl. 9 5.5 3,5 4,5 5.5 / 2.5 5.5 7.8 / 4.5 8.0 / 5.0 - blank cutting 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 - heating (up to 10 blanks per charge) 1,5 - molding (stamping, bending, etc.) 0.2 0.5 2.0 3.0 0.5 1,0 3.0 3.0 - heat treatment (up to 10 blanks per charge) 3.0 3.0 3.0 / - 3.0 3.0 / - 3.0 / - - contour 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 - cutting edges 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 - fine-tuning 0.5 0.5 - - 0.5 / - - - - * In the numerator - for the pipe ⌀ 159 mm, in the denominator - for the pipe 820 mm ** Permissible thinning of the workpiece according to TU 1469 001-01297858-01, with 0.5 mm, i.e. 6-12% for workpieces with a thickness of 8-16 mm respectively *** Heat treatment for steel 09G2S is required when thinning in the cold state is 8%

Claims (1)

A method of forming box and tubular parts with double curvature, including forming a sheet blank by rotational local deformation for several transitions by deforming elements, the upper of which has a curvature less than the set in the transverse and longitudinal directions of the part, at least by the amount of spring, characterized in that at the first transition, shaping is carried out by rolling to obtain the required thinning of the billet sections of double curvature; at the second transition, ib the workpiece along the forming part, starting from its edges, and then along the midline, and at the third transition, bring the workpiece to a predetermined shape by eliminating the side deformations obtained at the first and second transitions by replacing the pressure and support deforming elements with an approximation of the radius of the pressure element to a given radius of the part in the transverse direction.

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