RU1810259C - Method of making laminate panels - Google Patents

Abstract

Usage: the invention can be used for manufacturing by the combined process of superplastic molding and diffusion welding of complex products such as panels. SUBSTANCE: sheet blanks of a filler are collected in a bag and connected to each other. they are installed in the tooling between the 2 sheets of sheathing internal and external, heated to a superplastic temperature and molded by applying pressure to the filler cavity until the filler cells are completely in contact with the sheathing sheets. The molding is carried out in three stages: at the first stage, the working pressure PI is applied to the filler cavity until the domes of the formed cells touch the shell sheets, at the second stage, the pressure Pg is applied between the inner and outer sheathing sheets, and the pressure Pa should not exceed the pressure Pi, in the third step, the filler and the inner sheathing are co-molded, increasing the pressure PI and decreasing the pressure Pr. 7 ill. 4mt s, fe

Description

The invention relates to the field of metal forming and diffusion welding, and can be used for the fabrication by the combined process of superplastic forming and diffusion welding of complex products, such as panels.

The aim of the invention is to improve the quality of manufacture of panels by reducing thinning in the near-heat and corner zones of the filler without reducing the utilization of the material and complicating the process.

The essence of the method lies in the fact that the reinforcing elements are formed in the molding process from sheet blanks placed between the sheathing filler, by means of the proposed scheme G supply of the working medium.

Considering the use of sheet blanks of reinforcing elements, it is recommended to change the approach to choosing the thicknesses of the initial blanks of the skin and filler,;

In the usual method of manufacturing panels by molding the filler without the use of reinforcing elements, with sufficient accuracy for technological calculations, the abortion of the sheet thicknesses of the sheathing and filler blanks is determined based on the conditions:.

00

Oh GO

ate

H)

 d zn (1-n), d 2-5zn (1-n) + 5zo,

(D (2)

where d1 is the specified thickness of the edges of the panel;

5 characters - filler blank thickness

in the conventional method of manufacturing parts;

Ј n - deformation of the filler;

b 2 - a given thickness of the panel skin;

5 zo - thickness of the sheathing sheet; In the case when the length of the cell is much greater than its width;

e n 11

V1 + still

In the case of square checks

 F -1-1

fc n - | --------

(1 + Ј1н) 2 where е | н - linear deformation

(1+ -)

where H is the height of the panel;

B is the width of the panel.

From condition (1), we determine the thickness of the filler preform. The absence of thinning in the heat-affected zone makes it possible to choose a filler preform thinner by an As value, in the conventional method of manufacturing panels, thus in this case the thickness of the filler preform is:

b z d

knowledge

knowledge

 Le 5 en (1-АЈ),

where b zn is the thickness of the filler blank in the proposed method;

De - deformation of the filler in the heat-affected zone due to the presence of a weld.

Also taking into account that the sheet preparation of the reinforcing element is involved in the formation of the edge of the panel, we write condition (1) in the following form:

d Y-s nO-S b 3ap (t- In ar), (4)

where d zzr - sheet blanks of the reinforcing element;

Еар - deformation of the sheet blank of the reinforcing element.:.

In the case when the length of the cell is much greater than its width

Ae -11

V1 4-DЈ |

1-1

tap Y1 + e, ap where A B i - linear deformation of the filler in the heat-affected zone;

Ј lap-linear deformation of the workpiece of the reinforcing element.

In the case of square checks

Ae 11

e (1 + DE1) 2

1

o + m2

e (1 + H / B);

Aei In (1 +

U4L2 -9 +3 -l: 2l

) (1 +

 ) 0.3 + 1p (1+),

where ds is the diameter of the weld core,

-determined from geometric considerations, taking into account the peculiarities of the formation of filler in the heat affected zone.

Preset thickness - skin at the end of molding:

b 2 b n) + 5 charge (1-bar) + 5 vol.

(5)

Jq 35

40

45 50

55

where 6 about - the thickness of the sheet billet sheathing.

The thickness of the sheathing preform, taking into account the preservation of the specified panel parameters, is equal to the sum of the thinning of the reinforcing sheet and the filler.

In FIG. 1-6 schematically represent the steps of the method; in FIG. 7 is a flow chart of a method.

In FIG. 1-6 the following designation is adopted: 1,2 - filler, 3 - upper skin, 4,5 - reinforcing elements, 6 - lower skin, 7 - forming reinforcing element.

The rigging (see Fig. 7) consists of the upper 8 and lower 9 parts of the stamp, to which the power plates 10 and 11 are attached. Pipelines 12,13 are designed to purge the cavity of the stamp 14 with inert gas. Through pipelines 15.16, pressure is applied to the sheet blanks of the reinforcing elements and sheathing, and through line 17 to the sheet blanks of the filler. Filler sheets 1.2 are placed between sheets 4.5 and 3.6.

The method is as follows.

The filler sheet blanks are assembled into a bag and welded together, installed in the tooling between the sheet blanks of elements 4,5 and the sheet blanks of cladding 3,6 (Fig. 1), and molding is performed by applying pressure Pi between the sheets of filler 1 and 2 before touching the domes of the expandable cells of the sheet blanks of the reinforcing elements (Fig. 2), the moment of puncturing the domes of the cells of the blanks of the reinforcing elements is determined empirically or using special indicators. Delayed forming of the sheet blanks of the reinforcing elements after the formation of a contact area between them and the cupola of the filler cells eliminates a part of the metal from the deformation process, which leads to an increase in the thinning of the sheet blank of the reinforcing element in the rib area.

The total thickness of the filler sheets and reinforcing elements in the corner zone at the end of the molding is greater than in the case of forming one filler with the thickness of the workpiece. equal to the total thickness of the sheet of the reinforcing element and the filler in the considered method. Therefore, the premature molding of the sheet blank of the reinforcing element causes the sheet blanks of the filler and reinforcing elements to form as a thicker filler, with increased thinning in the corner zone.

Next, the pressure PZ is applied between sheets 4 and 3, and also between sheets 6 and 5. Since the pressure Pi is maintained during the formation of the sheet blank of the reinforcing element and the filler is still forming, it is necessary to choose the pressure P2 based on two basic conditions. The first condition is the filling of the space between cells by sheet blanks of reinforcing elements. For this, it is necessary that the speed of their molding is not less than the speed of molding of the filler. The second condition is that pressure 2 must not exceed PL, since otherwise deformation can occur. Thus, under both conditions, the equality of pressures Pi and P2 is optimal.

Forming sheet blanks of reinforcing elements takes place in more favorable conditions, since rigidity

the filler is increased due to the presence of a weld, this leads to the fact that, at equal pressures Pi and P2, the sheet of the blank of the reinforcing elements is formed faster, which contributes to the fulfillment of the first condition. In the case of a ratio of half the panel height to a cell width of less than 0.4 sheets, the blank of the reinforcing element fills the area between the forming cells to the weld (Fig. 4), If this ratio is more than 0.4, the critical distance between the walls of the filler cells, prep The complete filling of the space between them of the sheet blanks of the reinforcing elements arises until they completely adhere to the filler. Depending on this, thinning in the heat-affected zone is reduced to a greater or lesser extent. It must be emphasized that the second case is less common / than the first, which means that the problem associated with the drowning in the near-seam zone is almost completely solved.

In the next step, increase the pressure PI and reduce the pressure P2, until the cells are completely formed and the contact surfaces are welded (Fig. 5,6).

Formula and sampling Method for the manufacture of multilayer panels, which includes assembling sheet filler blanks into a bag, interconnecting them, placing the bag in technological equipment between blanks of reinforcing elements and sheathing sheets, forming it in a state of superplasticity the supply of a working medium between sheet blanks, which consists in the fact that, in order to improve quality by reducing thinning in the near-core and corner zones of the filler without reducing the coefficient of use of the material and more complicated and the technological process, molding is carried out in three stages: at the first stage, gas is supplied to the filler cavity with pressure Pi before it touches the sheet blanks of the reinforcing elements, at the second stage, gas is fed between the sheathing sheets and the sheet blanks of the reinforcing elements until the last touches the filler weld, observing the condition P2 Pi, at the third stage, the filler and the reinforcing elements are co-molded, increasing the pressure Pi and lowering the pressure Pa.

6920Sh