RU2523857C1 - Production of metal structures containing closed chambers with low geometrical height - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: prepreg layers cut out to patterns and forming solid mandrel are made from moulding mass, their shape complying with article inner cavities, Mandrels from moulding mass are made from material with high linear expansion factor and low mechanical properties and wrapped with anti-adhesion film. Prepreg blank layers are laid on prepared solid mandrels. Then, separate blanks are assembled with their forming elements into one-piece structure in the mould. Forming is performed by heating the mould with its contents. After forming, aforesaid moulding mass is destructed and removed via small-size individual holes.

EFFECT: lower power input, accelerated fabrication.

4 cl, 2 dwg

Description

The invention relates to the technology of manufacturing layered products of volumetric form containing closed cavities with a low geometric height, in particular to methods for manufacturing the aerodynamic surfaces of aircraft, their bodies or compartments, and other hollow panel-frame structures made of non-metallic composite materials.

The prior art technology for the manufacture of products from layered composite materials of volumetric form, containing closed cavities with low geometric height.

From the invention RU 2030336, IPC B64F 5/00, publication date 03/15/1995, [1], there is a known method of manufacturing structures containing cavities with a low geometric height, including the manufacture of prepreg layers cut according to the templates, the manufacture of forming solid mandrels, laying on solid the surface of the forming mandrel of the prepreg layers, installing the laid blanks into the mold, pressing when heating the mandrels placed inside the workpiece of the structure, and removing the mandrels from the product after pressing.

The disadvantage of the method [1] is the implementation of the hollow structures open, at least on one side, for removal after molding the mandrels.

From the invention RU 2217309, IPC B29C 51/28, B29C 51/30, B29C 43/12, B64F 5/00, publication date 11.27.2003 [2], there is a known method of manufacturing structures containing closed cavities with a small geometric height, including manufacturing the prepreg layers cut out according to the templates, the manufacture of the forming solid mandrels from the impression mass corresponding to the shape of the internal cavities of the product, the laying of the prepreg layers of blanks on the prepared solid mandrels, the assembly of the individual blanks in the mold with their shaping tooling elements in a single the structural blank, pressing by heating the mold with blanks and molding mandrels made from the impression mass placed in closed cavities inside the blank, and removing the impression mass from the inner cavity after molding.

A feature of the method [2], adopted as the closest analogue, is to produce a cast mass in the form of a fusible material, such as paraffin, which is poured into a sealed bag prefabricated in the shape of the product cavity, cooled in it, forming a solid mandrel with the bag, and when molding the product goes into a liquid state of aggregation and can be poured out of the mandrel after molding to facilitate its removal from the molded cavity of the product. This leads to an increase in the duration of the manufacture of structures and energy costs due to the need for heating to completely melt the fusible material, but does not guarantee the removal of the mandrel (paraffin) and bag from the cavity of the product through a small hole in its wall, which is a disadvantage of this method.

The technical result of the invention is to reduce energy consumption while reducing the manufacturing time.

The technical result also consists in reducing the time of placement of the mold with the design in the technological equipment that provides heating during molding.

The invention consists in the following.

A method of manufacturing structures containing closed cavities with a low geometric height, as in the closest analogue [2], includes the manufacture of prepreg layers cut according to the templates, the manufacture of solid forming mandrels from the impression mass corresponding to the shape of the internal cavities of the product, the laying of the prepreg blanks on prepared solid mandrels, assembly in the mold of individual workpieces with their forming elements of equipment into a single workpiece design, pressing by heating spring molds with blanks and molding mandrels placed in closed cavities inside the blank, made of impression material, and removal of impression mass from the internal cavity after molding, but unlike the closest analogue [2], mandrels from impression mass are made of material with a high coefficient linear expansion and low mechanical properties, mandrels from the impression mass are wrapped with a release film, after molding the impression mass of the mandrel is destroyed and removed from the closed cavity through a single tverstie small size.

The method is characterized in that the impression mass is made on a silicon-organic basis.

The method is characterized in that the impression mass is made on the basis of sodium salts of higher fatty acids, for example, dehydrated solid soap.

The method is characterized in that the impression mass is destroyed by an instrument with an ultrasonic tip. The invention is illustrated by drawings.

Figure 1 shows a section of a mold with a structure placed in it.

Figure 2 presents a General view of the design with cavities with low geometric height, made using the claimed invention.

A method of manufacturing structures containing closed cavities with low geometric height, is implemented as follows:

- make blanks prepared according to the templates of the prepreg layers;

- make solid mandrels from the impression mass with a high coefficient of linear expansion and low mechanical properties, corresponding in shape to the internal cavities of the product, and wrap them with a release film;

- lay the layers of the prepreg blanks on prepared solid mandrels;

- assemble in the mold individual blanks with their forming elements of the equipment in a single workpiece design;

- carry out pressing by heating the mold with the workpieces and placed in closed cavities inside the workpiece forming mandrels made of cast mass;

- after molding, the impression mass of the mandrel is destroyed and removed from the internal cavity through a single hole of small size.

In a preferred embodiment of the method, the impression mass is made on an organosilicon basis, or on the basis of sodium salts of higher fatty acids, for example, in the form of a dehydrated solid soap, and the impression mass is destroyed with an ultrasonic-tipped tool.

The implementation of the method is illustrated by an example of a snap for forming a radial fan impeller.

The method is carried out in a mold containing the upper 1 and lower 2 plates, split shell 3, ring 4, crackers 5 and 6, axis 7 and the central insert 8 (figure 1).

The individual blanks of the blades 9 and the blank of the central body 10, laid out on solid mandrels 11 and 12, made of impression mass with a high coefficient of linear expansion and low mechanical properties, with their forming elements of the equipment are assembled into a single blank of the structure, pulled together by a casing 3, and then on the bent edges of the blade blanks 9 lay out the rear 13 and front 14 discs.

A fully assembled mold is placed in technological equipment with heating elements, for example, between heated press plates (not shown). In this case, the rear 13 and front 14 discs are molded by direct pressing, and the sheathing of the blades 9 and the central body 10 is due to expansion when the impression mass is heated, from which the mandrels 11 and 12 of these structural elements are made.

After cooling the structure, the impression mass of the mandrels 11, 12 is destroyed and removed from the internal cavities of the product through single holes of small sizes. For example, the impression mass of the mandrel 11 of the blade 9 is removed through a single hole 15 of small size (figure 2).

In a preferred embodiment of the method, the impression mass is made on an organosilicon basis, or on the basis of sodium salts of higher fatty acids, for example, in the form of a dehydrated solid soap, and the impression mass of mandrels 11, 12 is destroyed by a tool with an ultrasonic tip, for example, an ultrasonic scaler (not shown) .

Similarly, structural elements with closed internal cavities, such as wingtips, flaps, ailerons, rudders, rudder trimmers, etc., can be manufactured.

Achieving the claimed technical result is ensured by the execution of mandrels from the impression mass with a high coefficient of linear expansion and low mechanical properties, which, compared with the closest analogue [2], provides a reduction in energy consumption while reducing the manufacturing time of structures. Since the design should not be in a heated state when removing the impression mass of the mandrels in technological equipment with heating elements, the placement time of the mold with the structure in the technological equipment is also reduced.

Presented in the description of the invention, a set of features and an example implementation of the method are sufficient to implement the invention at any specialized enterprise.

Claims (4)

1. A method of manufacturing structures containing closed cavities with low geometric height, including the manufacture of prepreg layers prepared according to the templates, manufacturing solid forming mandrels from the impression mass corresponding to the internal cavities of the product, laying prepreg blanks on prepared solid mandrels, assembly in a press -form of individual blanks with their forming elements of equipment into a single blank of the structure, pressing by heating the mold with blanks and size molding mandrels made in cast cavities inside the preform made of cast mass and removal of cast mass from the internal cavity after molding, characterized in that mandrels from cast mass are made of material with a high coefficient of linear expansion and low mechanical properties, mandrels made from cast mass are wrapped release film, after molding, the impression mass of the mandrel is destroyed and removed from the closed cavity through a single hole of small size. 2. The method according to claim 1, characterized in that the impression mass is made on an organosilicon basis. 3. The method according to claim 1, characterized in that the impression mass is made on the basis of sodium salts of higher fatty acids, for example, in the form of a dehydrated solid soap. 4. The method according to claim 1, or 2, or 3, characterized in that the impression mass is destroyed by an instrument with an ultrasonic tip.

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