RU2727404C1 - Device for drawing cylindrical shells from sheet metals with plane anisotropy of mechanical properties - Google Patents

Abstract

FIELD: metal forming.

SUBSTANCE: invention relates to metal forming and can be used for drawing of cylindrical shells from sheet metals with plane anisotropy of mechanical properties. Removable ring with shaped smoothly conjugated cone cavity is fixed on puncheon-matrix. Ring is fixed taking into account the direction of formation of festoons in the cylindrical shell.

EFFECT: elimination of festoon formation during drawing cylindrical shells.

1 cl, 5 dwg

Description

The invention relates to the processing of metals by pressure and can be used to obtain cylindrical shells using the operation of drawing from sheet metals with in-plane anisotropy of mechanical properties. Sheet metals in most cases have in-plane anisotropy of mechanical properties, which manifests itself in the formation of scallops (ears) at the edge of the part after drawing. As a blank during drawing, a circle obtained by cutting is used. In some cases, the height of the scallops is 15 ... 20% of the height of the cylindrical shell. As a result, the waste of metal and the cost of the part increase.

A device is known in which to eliminate scallop when drawing round billets made of metals with planar anisotropy of mechanical properties, matrices with a variable radius of the drawing edges are used. A smaller radius is given in those places of the anisotropic workpiece where it is required to slow down the metal flow and increase the drawing height and vice versa (Fig. 108, p. 128). [1] (Romanovsky VP Handbook on cold stamping. - 6th ed., Revised and supplemented - Leningrad: Mechanical engineering. Leningrad branch, 1979. - 520 p.). The disadvantage of the matrix design is the possibility of its use for sheet metal with a uniquely fixed in-plane anisotropy of mechanical properties, and the size of the variable value of the radii of the pulling edges is determined by the method of experimental selection, which increases the labor intensity of production preparation. In addition, when a new batch of sheet metal arrives with different planar anisotropy values

it becomes necessary to replace the matrix with a matrix with a different variable value of the radius of the extruding edges, which increases the cost of producing cylindrical shells.

Known device for drawing cylindrical shells made of sheet metals with planar anisotropy of mechanical properties (patent RU No. 2691016 C1, IPC ⁸ B21D 22/00, publ. 07.06.2019, bull. No. 10) adopted as a prototype, which has an upper and lower plate , guide columns and bushings, a die for punching, a punch-matrix for punching and drawing with an exit section and a replaceable ring with a lead-in section fixed in it, upper and lower clamps, a lower buffer. The disadvantage of the stamp is that the lead-in section of the replaceable matrix ring is made with a variable value of the radii of the pulling edges along the perimeter, which does not allow increasing the degree of drawing in one operation.

The objective of the present invention is to save sheet material by reducing scrap metal for trimming by eliminating scalloping during drawing, as well as reducing labor intensity when producing cylindrical shells from sheet metal with planar anisotropy of mechanical properties.

изменяющийся по зависимости:The task is achieved by the fact that in a device for drawing cylindrical shells made of sheet metals with in-plane anisotropy of mechanical properties, it contains the upper and lower plates, guide columns and bushings, a die for punching, a punch-matrix for punching and drawing and a replaceable ring fixed in it with lead-in section, upper and lower clamp and lower buffer, while in the replaceable ring the lead-in section has a taper angle variable along the perimeter

changing by dependency:

for different values of the angle γ of the radius vector of the perimeter contour

, равным 15÷20°, высотой Н_мз, равной 1÷2 высоты получаемой оболочки, радиусом применяемой круглой заготовки R_з и радиуса R_x зависящего от плоскостной анизотропии механических свойств листового металла, кроме того в устройстве сменное кольцо ориентируют в пуансон-матрице максимальным углом конусности

в направлении образования фестонов при вытяжке цилиндрической оболочки.lead-in section with maximum taper angle

equal to 15 ÷ 20 °, height H _mz , equal to 1 ÷ 2 of the height of the resulting shell, the radius of the applied round workpiece R _s and the radius R _x depending on the planar anisotropy of the mechanical properties of the sheet metal, in addition, in the device, the replaceable ring is oriented in the punch-matrix with the maximum taper angle

in the direction of the formation of scallops when drawing the cylindrical shell.

FIG. 1 shows a general view of the hood device;

in fig. 2 - assembly punch-matrix for drawing;

in fig. 3 - cylindrical shell with scallops, height Δh;

in fig. 4 is a diagram for determining the radius R _x ;

in fig. 5 is a top view of the lead-in part of the punch-matrix assembly for drawing.

The device (Fig. 1) consists of a bottom plate 1, on which a die for punching 2 is fixed, a pressure ring 3, pushers 4, screws 5 for attaching to the bottom plate of the draw punch 6, screws 7, guide columns 8, guide bushings 9, upper plates 10, upper clamp 11, special screws 12, punch-matrix 13 for punching and drawing with an outlet section of the cavity, screws for attaching the punch-matrix 13 to the upper plate 14, ejector 15, shank 16, pusher 17, replaceable ring 18 with a lead-in section of the profile form fixed in the punch-matrix 13, pressure springs 19.

In the device (Fig. 1), first in the cavity of the punch-matrix 13, a replaceable ring 18 is fixed, in which the lead-in part is made with a taper angle at a value of the radius R _x = 0, a workpiece-circle with a radius of R _{z is} cut out and its drawing is performed to obtain a cylindrical shell (Fig. 3). In the cylindrical shell, the direction of formation of scallops is determined relative to the direction to rolling. The height of the cylindrical shell is measured along the depression and along the scallop (Fig. 3) and build

graph (Fig. 4) for a given radius R _{s of the} workpiece-circle. Changing the values of the angle γ of the radius vector (Fig. 5) of the perimeter contour of the lead-in section from 0 to 90 ° according to the expression:

=15÷20° и высоты конусной заходной части Н_мз=1÷2 высоты получаемой цилиндрической оболочки.determine the change in the taper angle of the profile cavity of the lead-in part of the ring, at the given values of the maximum taper angle

= 15 ÷ 20 ° and the height of the conical lead-in part H _mz = 1 ÷ 2 of the height of the resulting cylindrical shell.

и вершинами, расположенными па линии сопряжения с рабочей поверхностью пуансон-матрицы 13. Для стабильности процесса формоизменения заготовки на верхней кромке заходного участка полости сменного кольца 18 выполнены радиусы закругления, равные 2÷4 толщинам листовой заготовки. Сменное кольцо 18 закрепляют на пуансон-матрице 13 с учетом направления образования фестонов в цилиндрической оболочке. Если фестоны относительно направления к прокатке располагаются под 45°, то сменное кольцо 18 ориентируют максимальным углом конусности под 45° относительно направления к прокатке полосы или ленты листового металла, или вдоль и поперек прокатки, если фестоны образуются в этом направлении. Деталь получается без фестонов. Полученную цилиндрическую оболочку удаляют из рабочего пространства устройства с помощью толкателей 4 нижнего буфера, или выталкивателем 15 и толкателем 17. Полосу подают на шаг подачи и процесс повторяют. При получении листового металла с другой плоскостной анизотропией механических свойств, проводят аналогичную настройку устройства с заменой сменного кольца 18 на сменное кольцо, профильная заходная часть полости которого выполнена с переменнойTo obtain a finished part without scallops, a replaceable ring 18 with a profile, smoothly conjugated conical cavity with taper angles is installed in the cavity of the punch-matrix 13 corresponding to the calculations of the radii R ₃ and R _x

and the tops located on the line of conjugation with the working surface of the punch-matrix 13. For the stability of the process of shaping the workpiece on the upper edge of the lead-in section of the cavity of the replaceable ring 18, radii of curvature equal to 2 ÷ 4 thicknesses of the sheet workpiece are made. The replaceable ring 18 is fixed on the punch-matrix 13, taking into account the direction of formation of scallops in the cylindrical shell. If the scallops are at 45 ° relative to the rolling direction, then the replaceable ring 18 is oriented with a maximum taper angle of 45 ° relative to the rolling direction of the strip or sheet metal strip, or along and across the rolling, if scallops are formed in this direction. The detail is obtained without scallops. The resulting cylindrical shell is removed from the working space of the device using pushers 4 of the lower buffer, or pusher 15 and pusher 17. The strip is fed to the feed step and the process is repeated. When receiving sheet metal with a different planar anisotropy of mechanical properties, a similar adjustment of the device is carried out with the replacement of the replaceable ring 18 with a replaceable ring, the profile lead-in part of the cavity of which is made with a variable

taper, taking into account the in-plane anisotropy of the mechanical properties of the stamped sheet metal.

As a result of using the proposed device with a set of replaceable rings 18 with a tapered lead-in part, the labor intensity of manufacturing cylindrical shells and waste for trimming is significantly reduced by eliminating scalloping during drawing. The device can be used to obtain cylindrical shells with a given value of the height of the scallops by changing the radius of curvature in the lead-in part of the replaceable ring 18, or the angle of taper, if required when making a cylindrical shell.

Claims (7)

1. A device for drawing out cylindrical shells made of sheet metals with planar anisotropy of mechanical properties, containing the upper and lower plates, guide columns and bushings, a die for punching, a punch-matrix for punching and drawing with an inlet section and a removable ring with a lead-in section fixed in it , upper and lower clamps and a lower buffer, characterized in that to eliminate scalloping, the lead-in section of the replaceable ring is made with a variable taper angle around the perimeter

depending on the dependency:

, Where γ is the angle of the radius vector of the perimeter contour;

- maximum taper angle equal to 15 ÷ 20 °; H _mz - the height of a cylindrical workpiece obtained from a workpiece with a radius of R _s , taking into account the radius R _x , depending on the planar anisotropy of the mechanical properties of the sheet metal, equal to 1 ÷ 2 of the height of the resulting shell. 2. The device according to claim 1, characterized in that the replaceable ring is oriented in the punch-matrix with the maximum taper angle

in the direction of the formation of scallops when drawing the cylindrical shell.

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