RU2707024C1 - Die for forming panels - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention can be used in aircraft engineering, shipbuilding and other machine building. Die for forming panels, comprising a unit for controlling pressure on the puncheon, characterized in that the die is equipped with a device for simultaneous stretching of the panel, made in the form of wedge joints, movably connected to levers of the pressure control unit. At that panel tension force is defined by P_p=(P₃/cosα) cosγ, where α is wedge angle, degrees; γ is angle between plane of wedge and horizontal plane, degrees; P₃ – vertical wedge force, chr.

EFFECT: high quality of the obtained panels.

1 cl, 4 dwg

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of parts from sheet and layered materials at engineering enterprises.

Known stamp for forming panels by heat setting: ed. Maksimenkov V.I. and etc.; USSR copyright certificate No. 654084 class. V21D 11/00 01/28/1977, allowing the formation of panels with the regulation of the pressure on the panel, which improves the quality of the workpiece.

Disadvantages: the stamp does not allow receiving panels of double curvature.

Known stamp for shaping with heat setting of honeycomb panels: ed. Maksimenkov V.I. and etc.; USSR copyright certificate No. 1312828 class. V21D 11/00 1985. The stamp contains a die, a punch with a curved working surface, and a punch pressure control unit that allows shaping the panels to produce double curvature.

Disadvantages: when forming a honeycomb panel, it is impossible to provide a predetermined stretch value of the panel, which affects the quality of manufacture of the panel.

This invention is aimed at eliminating the disadvantages of this design.

Technical result: improving the quality of the panel, which is achieved by the fact that the stamp for forming the panels, including a die, a punch with a curved working surface and a pressure control unit on the punch, characterized in that the stamp is additionally equipped with means for simultaneously stretching the panel made in the form of wedge joints movably connected to the levers of the pressure control unit on the punch, and the tensile force of the panel is determined by the dependence

where α is the angle of the wedge, deg .;

γ is the angle between the plane of the wedge and the horizontal plane, deg;

P ₃ - the vertical force of the wedge, kgf.

The use of stretching in the process of forming the panel allows to stretch the inner and outer skin and the honeycomb cells connected to them. At the same time, the faces of the cells remain rectilinear, that is, they do not lose their geometric shape, which ensures the required quality of the resulting panel.

In FIG. 1 shows the calculation of tensile forces depending on the angle of the wedge.

In FIG. 2 shows a stamp for forming panels.

The stamp consists of a pressure control unit for the punch, including: matrix 1, punch 2, levers 3, on which the load 4 is fixed, in contact with the punch using stops 5 and transferring the weight of the load 4, mounted on the levers 3, which, in turn, movably connected to the wedges 6, moving in the guides 7 and in contact with the plates connected to the panel 8.

The stamp works as follows: the blank of the panel 8 is installed on the matrix 1; on top of the panel set the punch 2; levers 3 with loads 4 are moved to the working position until the stops 5 of the punch 2 touch; the wedges 6 come into contact with the plate connected to the panel 8.

The stamp is placed in an oven and heated. At high temperatures, the yield strength of materials decreases sharply. Under the action of the load applied to the panel, the process of its deformation begins, which continues until it is fully adhered to the matrix.

The process of forming the panel is accompanied by its stretching with the help of wedges 6. After the completion of the forming, the furnace is turned off and after the die is cooled, followed by disassembly, the quality of the resulting panel is determined.

Example

The forming process is carried out in a stamp with heating in a furnace.

A honeycomb panel consisting of two skins connected to a honeycomb core. Sheathing material - OT4-1 titanium alloy. The filler is made of titanium alloy VT1-0; panel length 1000 mm; panel height 15 mm; the radius of the punch is 500 mm.

After completion of the shaping, the deformation e of the outer skin is determined by H / R = 15/500 = 0.03, i.e. ε ₁ = 3%.

The relative elongation of the skin in the cold state is 11%.

When the panel is heated, the elongation of the panel increases to 18%.

When developing a stamp, we select the angle of inclination of the wedge α = 10 deg., Then the deformation for both sides of the wedge is ε ₂ = 6.8% when moving the wedge 200 mm. The wedge angle is selected taking into account the plastic characteristics of the panel.

The total deformation of the panel is ε ₃ = ε ₁ + ε ₂ = 9.8%.

Consider the deformation of the placeholder cells.

Forming without stretching the panel is shown in FIG. 3. The dimensions of the filler cells on the inner side of the panel in contact with the filler are compressed (Fig. 3a), and on the outer (Fig. 3b) are stretched. In this case, the faces of the cells lose their rectilinear shape.

In FIG. 4 shows the shaping with stretching of the panel.

Comparing the nature of the deformations of the aggregate, it follows that in the first case, the resulting deformations on the inner cell and the outer have different signs (compression and tension), which leads to distortion of the faces of the cell, as a result, the quality of the panel decreases.

The use of tension ensures the deformation of one sign (Fig. 4a and Fig. 4b), which eliminates the distortion of the cell faces and is sufficient to obtain a high-quality panel, as well as reducing the laboriousness of manufacturing the panel by more than 1.5 times.

Claims (5)

A stamp for forming panels, including a matrix, a punch with a curved working surface and a pressure control unit on the punch, characterized in that the stamp is additionally equipped with means for simultaneously stretching the panel, made in the form of wedge joints, movably connected to the levers of the pressure control unit on the punch, and the force panel stretching is determined by

where α is the wedge angle, deg; γ is the angle between the plane of the wedge and the horizontal plane, deg; P ₃ - the vertical force of the wedge, kgf.

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