RU2118219C1 - Method of forming-drawing articles of sheet material - Google Patents

Abstract

FIELD: sheet forming, namely in aircraft industry, ship building and other industry branches of machine engineering at making complex-shape sheet articles. SUBSTANCE: method comprises steps of acting upon sheet blank placed in container over deformed material by means of rigid die; using pack of sheet blanks as deformed material, pack with height Hl of its loading part equal to 1-1,5 diameter Db of blank; shaping hollow article at acting by contact pressure upon lateral surface of blank pack at side of inner wall of said container in its narrowed zone at height Hn being no less than diameter Db of blank. Outer diameter Dout of blank is changed from its value Db to diameter Dfl of flange portion of article. Total height H_∑ of blank pack and inclination angle of generatrix of cone surface of blank pack in narrowed zone of container are determined according to expressions: H_∑=Hl+Hn=(2-2.5)Dout; αn=arctg(Dout-Dfl)/2Dout, where αn - inclination angle of lateral surface of blank pack relative to its axis in narrowed zone; Db- initial diameter of blank; D fl.out- outer diameter of blank flange; Hl - height of blank pack in loading zone of container; H_∑- total height of blank pack; Hn - height of blank pack in narrowed zone. EFFECT: enhanced efficiency. 1 cl, 5 dwg

Description

 The invention relates to the field of metal forming, in particular to sheet stamping, and can be used in aircraft, shipbuilding and other engineering industries in the manufacture of hollow sheet metal parts of complex shapes.

 A known method of forming products from sheet metal by pressure from the side of the deforming material, in which the sheet blank takes the form of a matrix under the action of the deforming material, which can be used as an elastic medium (eg, rubber) [1].

 The disadvantage of this method is that the pressure from the side of the deformable material, sufficient to stamp the central part of the workpiece, is insufficient to prevent folding of the material in the flange part of the workpiece.

 The closest technical solution to this invention is a method of stamping-drawing products from sheet metal, in which a rigid matrix is applied to a sheet blank located in a container above a deformable material [2].

 The disadvantages of this method are the need for a double force effect on the deformable material for the manufacture of one product, as well as in increased metal consumption for the manufacture of products.

 The technical result achieved by using the proposed technical solution consists, firstly, in increasing the productivity of stamping hollow sheet products by eliminating the operation of smoothing the deformed metal and eliminating the operation of trimming the workpiece flange, and secondly, in expanding the technological capabilities of stamping complex parts forms by eliminating the stagnant ("dead") zone of ductile metal in the supraflange part of the workpiece and, thirdly, by increasing the CMM by eliminating festoon Azings in the flange when drawing the product.

где
H_загр - высота пакета заготовок;
H_суж. - высота сужения контейнера;
D₀ - исходный диаметр заготовки;
D_фл.н - наружный диаметр фланца изделия;
α - угол наклона образующей конической поверхности контейнера к его оси.Achieving marked technical result contributes the fact that in the process of punching-drawing of sheet metal, wherein in the sheet stock positioned in the container above the deformable material affect rigid matrix as a deformable material is package blanks to the height of its loading portion H _{contaminated .} in the range of one to one and a half blank diameter D _0, and shaping the sheet blank into the article accompany influence on the lateral surface against the inner wall of the container contacts the stack of workpieces pressure in the region of its constriction at a height H _suzh narrowing of at least one diameter D ₀ with the change in initial diameter blanks D ₀ to the desired diameter of the flange part D _fl , and the angle of inclination of the generatrix of the lateral conical surface to its axis in the narrowing zone of the container and the height of the package is set according to the dependencies
H + H _{contaminated suzh} = (2,0 - 2,5) D _0;

Where
H _zag - the height of the package blanks;
H _narrow - the height of the narrowing of the container;
D ₀ - the initial diameter of the workpiece;
D _fl.n - the outer diameter of the product flange;
α is the angle of inclination of the generatrix of the conical surface of the container to its axis.

 These features of the proposal are its differences from the prototype and determine the novelty of the proposal. These differences are significant, because they provide the creation of a positive effect, reflected in the purpose of the proposal, and are absent in the known technical solutions with the same effect.

 The drawing shows a diagram of the implementation of the method of stamping-drawing products from sheet metal, which shows: figure 1 - position at the time of stamping-drawing products after loading the container with a hollow package of blanks; in FIG. 2 - position after stamping the product and before removing it from the matrix; figure 3 - position at the time of stamping the loaded package of blanks; in FIG. 4 - position before loading the package of blanks in the device; figure 5 - position after loading the package of blanks in the device.

The proposed method is carried out in a device that includes the following main details:
- a matrix 2 mounted on the upper fixed table of the press 1 with an ejector 3 driven by a rod 4 (the ejector drive is conventionally not shown);
- mounted on the lower drive table of the press 5 using the base 6, the stem-punch 7 with the hydraulic cylinder-container 8, the upper part of which serves as a container for placing a package of blanks, and on the upper end of the hydraulic cylinder-container 8 there is a retaining element 9 in the form of a holder with an inner conical surface 10.

 The sealing of the cavities 11 and 12 of the hydraulic cylinder is provided by the rubber rings 13. A loading window 14 is formed in the hydraulic cylinder 8 for loading the cavity 15 of the container hydraulic cylinder 8 with a workpiece package 16, which is moved to the device loading zone using the manipulator 17 (not shown conventionally), after which the package 16 consisting of blanks 18, 19, 20 ... using a pusher 21 (not shown conditionally) is moved into the loading cavity 15 on the end surface 22 of the piston-punch 7 (see figures 4 and 5).

 Deformable blanks in retaining element 9 and stamped product are assigned positions 23, 24, 25 and 26, respectively.

The proposed method is implemented as follows. The blanks 18, 19, 20 ... (comma film and grease), collected in the boot package 16 height H _contaminated = (1,0-1,5) D _{0 (0} where D - diameter of the workpieces in the package) is placed in a cylinder -container 8 and is mounted on the piston-punch 7 (see FIGS. 4 and 5), as a result of which, during the working stroke of the press, its table 5 rises, providing first contact of the flat sections of the matrix 2 and the retaining element 9; then raising the boot package until it comes in contact with the package of stamped blanks 23, 24, 25 ...; when creating the required compression force of both packages of preforms, the uppermost workpiece takes the form of the product 26 (see figure 1).

The shaping of the part 26 is carried out when creating a counter-pressure bleeding fluid (from the cavity 12 of the hydraulic cylinder 8), the value of which is set sufficient to prevent the joint from opening on the flat sections of the matrix 2 and the retaining element 9. The backward stroke of the press is accompanied by lowering of the press table 5 with the lower part device to a height H ₁ sufficient to remove the stamped part 26 from the working area of the device, which is pushed out of the matrix 2 by the ejector 3 (see figure 2).

After that, the following cycles of stamping parts are carried out until the piston-punch 7 is in the position according to FIG. 3, in which the entire loading package of blanks has entered the retaining element 9, and it is necessary to load the next package of blanks into the device. To do this, lower the press table 5 to its lowest position, and by supplying liquid under pressure to the cavity 12, lift the hydraulic cylinder container 8 to its highest position (see Fig. 4), as a result of which the lower platform of the loading window 14 is installed at a height H from the movable press section 5. After that, the manipulator 17 (on which the pre-installed preform 18, 19, ... 20, collected in the package 16) provide a pushing of the package 16 height H _contaminants into the feed cavity 15 of the hydraulic cylinder container 8 by means of a pusher 21 (see Fig. 4).

 In the future, the next batch of parts is stamped using a newly loaded package of blanks.

Maximum height H _contaminated package from the blanks 16, 18, 19, 20, ..., and with the films in the hydraulic cylinder lubricant container 8 must be less than one and a half diameter D ₀ package blanks, i.e. H _load D ₀ = 1.5 (where D ₀ -.. The diameter of the workpiece 18, 19, 20), since at high values of H _contaminated with force for forming parts by means of the press slider side deformable medium will significantly increase due to increased friction forces between the package of blanks 16 and the wall of the hydraulic cylinder-container 8. Using the same package of blanks 16 with a height of H _min = D ₀ leads to a decrease in stamping performance due to the frequent loading of the device by blanks 16.

Therefore, the package of blanks with films and grease for refueling the device must be at a height H _zag not less than one D ₀ and not more than one and a half diameters of the blanks D ₀ , i.e. H _load = (1.0-1.5) D ₀ .

In order that in the container 8 originally laid in the hydraulic cylinder 8 in the deformable billets 23, 24, 25 ... when moving in the retaining element 9 along the forming surface 10, the stamping of products 26 according to the matrix 2 is carried out without folding of the stamped material, it is necessary that the height H _narrow the package of blanks 23, 24, 25 ... in the retaining element 9 was not less than the initial diameter D _{0 of the} blanks, i.e. H _restriction ≥ D ₀ .

При этом α_суж - угол наклона образующей конической поверхности пакета заготовок к оси этого пакета согласно фиг.2 устанавливают из следующего соотношения:

Усилие пресса P_ш при штамповке-вытяжке изделий по предложенному способу устанавливается из условия создания контактных давлений q_k на боковой поверхности пакета заготовок 23, 24, 25... (в зоне сужения контейнера) и на поверхности фланцевой части изделия в пределах от одного до двух пределов прочности σ_в штампуемого материала, т.е. q_к = (1-2) σ_в. Следовательно:

Пример осуществления способа.The total height of the package of blanks H _Σ after loading into the device, taking into account the height of the package of blanks H _suz according to formula (2) in the narrowing zone of the hydraulic cylinder-container 8 and the height of the loading package of blanks H _zag according to formula (1) will be:

In this case, _αsub — the angle of inclination of the generatrix of the conical surface of the package of blanks to the axis of this package according to FIG. 2 is established from the following relation:

The press force P _W during stamping-drawing of products according to the proposed method is established from the condition of creating contact pressures q _k on the side surface of the package of blanks 23, 24, 25 ... (in the zone of narrowing of the container) and on the surface of the flange part of the product in the range from one to two tensile strengths σ _{in the} stamped material, i.e. q _k = (1-2) σ _c . Hence:

An example implementation of the method.

откуда

Согласно формуле (1) устанавливаем полную высоту пакета заготовок H_Σ :
H_суж. = D₀ = 285 мм; H_загр. = 1,5•D₀=428 мм; H_Σ = 2,5D_o= 713 мм.
Количество заготовок m, загружаемых в устройство для осуществления способа при исходной толщине заготовки S₀ =5 мм составляет

Усилие пресса P_ш, потребное для штамповки конических изделий заданной формы составляет

Таким образом, для осуществления предложенного способа установлены размеры пакетов заготовок и силовые параметры оборудования для изготовления деталей заданной формы.For stamping and drawing of a conical part made of DDIM alloy (σ _in = 7 kgf / mm ² ) with outer and inner flange diameters D _fl.n = 250 mm and D _fl.vn. = 150 mm and the diameter of the bottom of the product D _bottom = 50 mm with an inclination of the product wall β = 45 ^° and with a wall thickness S ₀ = 5 mm from the condition of equality of the area of the workpiece and the product we have:

where from

According to the formula (1) we establish the total height of the package of blanks H _Σ :
H _narrow = D ₀ = 285 mm; H _download = 1,5 • D ₀ = 428 mm; H _Σ = 2.5D _o = 713 mm.
The number of preforms m loaded into the device for implementing the method with the initial preform thickness S ₀ = 5 mm is

The press force P _w required for stamping conical products of a given shape is

Thus, to implement the proposed method, the dimensions of the packages of blanks and the power parameters of the equipment for the manufacture of parts of a given shape are established.

The developed method of stamping and drawing out hollow products from sheet metal was tested in laboratory conditions for the manufacture of conical parts from workpieces with a diameter of D ₀ = 30 mm and a thickness of S ₀ = 0.5 mm i.e. the part considered in the example is practically executed at a scale of 1:10.

Claims (1)

 \ \ \ 1 A method of stamping and drawing metal sheet products, comprising applying a rigid matrix to a sheet blank located in a container above a deformable material, characterized in that a package of sheet blanks with a height H <Mv> zagr <D> is used as a deformable material equal to one to one and a half diameters D <Mv> about <D> of the workpiece, and the formation of a hollow product is carried out by pushing a package of sheet blanks in the tapering part of the container, acting from the side of its inner surface with contact pressure m on the side surface of the bag and changing the diameter D <Mv> about <D> of the workpiece to a diameter equal to the diameter of the flange part of the product D <Mv> fl <D>, while the height of the tapering part of the container H <Mv> const <D> set equal to at least the diameter D <Mv> o <D> of the workpiece, and the angle $$$ of the taper of the tapering part of the container is selected from the expression \\\ 6 $$$ \ \ \ 1 and the total height of the package of workpieces in the container is \\\ 6 $$$

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