RU2696796C1 - Method for manufacturing large-size flange structure from layered polymer composite materials - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building, aircraft engine building and can be used for production of large-size flanged structures from polymer composite materials (PCM). Method of making large-dimensional flat structure from laminar PCM includes laying prepreg trellis and anspatial shells on the body of the shaping device with formation of transverse flanges from the ends prepreg by use of elastically deformable elastic forming element, limited along external surface, hardening at heating, cooling, machining both at ends, and internal and / or external sides of flanges with opening of mating holes in them. Molding is carried out at temperature not lower than expansion temperature of elastically deformable material of elastic molding element. When forming flange on structural part of flange formed by ends prepreg path and non-core shells, on one and / or other side, pre-packed packets of additional layers are laid prepreg to create allowance for flange machining from outer and / or inner side of flange. When shaping the flange having an angle of more than 0 deg with respect to the path and the envelope, in the process of laying between the ends of layers prepreg trellised and extraneous shells forming a flange, separating film is laid to eliminate gluing of layers of prepreg, having adhesiveness.

EFFECT: method allows to manufacture large-size products of both closed and open contour with flanges of various configuration and thickness with guaranteed provision of mechanical strength of flange connections, reliability and quality of design.

1 cl, 2 dwg

Description

The invention relates to the field of mechanical engineering, aircraft engine and can be used for the manufacture of large-sized flange structures from layered polymer composite materials (PCM).

A known method of manufacturing a flange in which the flange is manufactured separately as an independent structural unit by forming on a snap by successively stacking preformed three-dimensional (3D) blanks from woven or interlaced fibers of various densities with their subsequent densification by a polymer matrix in one of the known ways. One of the blanks determines the mechanical strength of the flange and is structural, and the other two, laid on the inner and outer surfaces of the structural blank without intersecting with its fibrous structure, are machined to ensure that the contacting surfaces of the flange fit to the surfaces of the parts with which it is in contact with the structure ( patent RU 2481950, IPC В29С 70/54).

The disadvantages of this method are:

- limited technological capabilities in the manufacture of large structures, low manufacturability and high complexity of manufacturing, due to the need for pre-manufacturing blanks of woven or bound fibrous shapes of different densities, each of which is a three-dimensional (3D) prefabricated blank, specialized equipment with software for weaving is required each blank individually and equipment for their compaction a black matrix one of the known methods;

- the presence of an additional mounting unit for the flange with the shell structure.

Common features of the analogue and the claimed invention are:

- the possibility of forming a flange from composite materials;

- laying blanks on the inner and outer surfaces of the structural blank without intersecting with its structure in order to form a technological allowance for machining to ensure that the contacting surfaces of the flange fit to the surfaces of the parts with which it is in contact with the structure.

The closest in technical essence and the achieved result to the claimed technical solution relates to a method of manufacturing a sound-absorbing device of a turbojet engine, including the manufacture of a prefabricated ring structure from three or more autonomous sections of the flange structure, fastened around each other in a circle. Each section is made by laying the prepreg layers of the path and non-path shells on the forming fixture body with the formation of transverse flanges from the ends of the prepreg by installing a rigid forming element in the form of an assembly fixture cover followed by compression, curing during heating, cooling, and machining the ends of the flanges with opening them docking holes (patent RU 2560639, IPC F02C 7/24).

The disadvantages of this method are:

- limited technological capabilities in the manufacture of large-sized enclosed shell-type products of closed loop, consisting in the impossibility of high-quality compaction of the layered composite material by the thickness of the flange and the area of its interface with the power shell by compression between the hard parts of the forming tool due to the simultaneous change in the geometry of the structure in mutually opposite directions as a result of shrinkage processes in a composite material under the influence of temperature.

- high complexity of manufacturing, additional material costs, since the method involves the manufacture of individual sections of the structure with their subsequent assembly.

Common features of the prototype and the claimed method are:

laying the prepreg of the path and non-path shells on the case of the forming tool with the formation of transverse flanges from the ends of the prepreg using the forming element, curing during heating, cooling, machining the ends of the flanges with the opening of the docking holes in them.

The objective of the invention is to provide a method of manufacturing a large-sized flange structure of layered polymer composite materials having advanced technological capabilities; improving the quality characteristics of the finished structure; reduction of economic and labor costs (cost) for the implementation of the method.

When solving this problem, the following technical result is achieved:

- the possibility of forming flanges of the structure, both open and closed loop of any type, for example, diametrical, ellipse, etc., simultaneously with the process of shaping the path and extra-path shells;

- the possibility of forming large-sized flange structures without significant economic and labor costs;

- ensuring high-quality compaction of the layered composite material along the thickness of the flange and the zone of its conjugation by the tract and off-track shells by using an element that is capable of creating uniform molding pressure in mutually opposite directions during the entire curing mode under the influence of temperature;

- the possibility of machining the flange on the outer and / or inner surfaces in order to ensure a good fit of the contacting surfaces of the flange structure with the contacting surfaces of the parts in the assembly structure.

The technical result is achieved by the fact that in the method of manufacturing a large-sized flange structure from layered PCMs, including laying layers of the prepreg of the path and extrathe shells on the housing of the forming tool with the formation of transverse flanges from the ends of the prepreg using the forming element, curing during heating, cooling, mechanical processing of the ends flanges with the opening of the docking holes in them, when forming the flange as a forming element use limited in external the surface is a forming element with elastic elastically deformable properties, while on the structural part of the flange formed by the ends of the prepreg of the tract and non-duct shells, on one and / or the other side, pre-packaged packages of additional layers of the prepreg are laid to create an allowance for the mechanical processing of the flange from the outer and / or the inner side of the flange, and molding is carried out under the influence of a temperature not lower than the expansion temperature of the elastically deformable material, the elastic form element.

When forming a flange from layered composite materials having an angle of more than 0 degrees with respect to the duct and non-duct shells, in the process of laying between the ends of the prepreg layers of the duct and non-duct shells forming the flange, a separating film is laid to prevent sticking of the prepreg layers having stickiness.

Distinctive features of the claimed invention:

as a forming element, a forming element limited on the outer surface, having elastic elastically deformable properties, is used, while on the structural part of the flange formed by the ends of the prepreg of the path and non-path shells from one and / or the other side, pre-packaged packages of additional layers of the prepreg are laid to create an allowance for mechanical processing the flange from the outer and / or inner side of the flange, and molding is carried out under the influence of temperature not lower than temperature urs expansion of the compliant material forming the elastic element.

When forming a flange from layered composite materials having an angle of more than 0 degrees, with respect to the tract and off-track shell, in the process of laying layers of the prepreg shells between the ends of the layers of the prepreg forming the flange, a separating film is laid to prevent bonding of the layers of the prepreg, which has some stickiness.

The claimed technical solution has a novelty and inventive step, as it contains significant distinctive features in comparison with the prototype and is characterized by a new combination and interconnection of essential common and distinctive features exhibiting new technical properties, new results are achieved that are not inherent in analogues.

In fig. Figure 1 shows the molding of a flange with an elastic forming element of a ring type of trapezoidal shape, in Fig. 2 - molding of the flange with an elastic forming element of a ring type of trapezoidal shape with the installation of a restrictive ring on the body of the forming tool.

The proposed method for the manufacture of large-sized flange structures from layered polymer composite materials is to perform the following sequence of operations:

- making a prepreg by impregnating a filler with a binder;

- Cut the prepreg into blanks;

- the formation of packages of additional flange layers of the prepreg by layering the estimated number of layers of the prepreg in a certain order in compliance with the orientation of the fibers in accordance with the reinforcement scheme;

- sealing packages of additional flange layers of the prepreg under pressure to a thickness as close as possible to the thickness of the cured composite material, taking into account the thickness of the cured monolayer of plastic;

- laying the blanks of the prepreg layers of the path and non-path shells on the body of the forming tool with the successive installation of, if necessary, embedded elements of the structure, for example, sound-absorbing panels, laying the separation film between the ends of the layers of the prepreg of the path and non-path shells used in the formation of the flange;

- installation of an elastic forming element of elastically deformable material, for example, from rubber 51-2110, fixing on the outer surface to prevent its displacement relative to the desired structural location;

- molding to the forming surface of the installed elastic forming element pre-compressed under pressure of the packet of prepreg layers for machining the flange from the inside, layering of the ends of the prepreg blanks of the path and non-shell shells with sequential removal of the separation film during molding, molding of the previously compressed packet of layers a prepreg for machining the flange from the outside;

- installation of a restrictive element on the housing of the forming tool on the outside of the flange;

- installation of a drainage bag;

- carrying out the curing mode under the influence of temperature and pressure;

- dismantling the drainage bag;

- machining, both at the ends and on the outer and / or inner surfaces of the flange with the opening of the connecting holes.

In the mode of molding the structure using one of the methods known at a temperature whose value should not be lower than the expansion temperature of the material of the elastic elastic-deformable element, in the layers of the flange prepreg due to the thermal expansion of the elastic-deformable material of the elastic forming element operating in a closed volume, directional pressure is created in mutually opposite directions, which allows you to create sufficient molding pressure to provide an interlayer contact section Lenia prepreg layers as the thickness of the molded flange, and the thickness of the adjacent Traktovaya and vnetraktovoy design shells and to compensate for the change in geometry of the structure as a result of shrinkage processes taking place in the composite material under heat.

An example of a specific implementation.

A large-sized sound-absorbing casing was made for a closed-loop protective circuit of an aircraft engine, the inner diameter of which is about 2000 mm with a flange forming an angle of 90 ° with respect to the path and off-line shells in the radial direction as follows.

A prepreg based on T-10-14 fiberglass impregnated with an ENFB-2 m binder is cut into the calculated number of blanks for the duct and off-line shells 2, 5 (Fig. 1), observing the fiber orientation according to the reinforcement pattern taking into account the dimensions of the formed flange. Two packages 9, 10 of additional layers are made from prepreg blanks by layering eight to ten layers of prepreg on top of each other in compliance with the fiber orientation according to the reinforcement scheme and compacted under the influence of mechanical pressure.

Three layers of the prepreg of the path sheath 2 are laid on the body of the forming tool 1 (Fig. 1, 2), laying to prevent sticking to the ends of the prepreg, designed to form the flange, a plastic film 3 (Fig. 1), a sound-absorbing filler 4 is installed (Fig. 1 ) with fixing the latter by winding the glass-impregnated binder impregnated with a binder (not shown in Fig. 1, 2), lay out three layers of the prepreg of the off-line casing 5, laying a plastic film 3 at the ends of the prepreg intended for forming the flange (Fig. 1). On the laid layers of the prepreg of the tract and non-path shells 2, 5, a forming element 6 of a closed ring type of rubber 51-2110 is installed, fixed with a clamp 7 to prevent its displacement relative to the desired structural location (Fig. 1). To the forming surface 8 (Fig. 1) of the installed forming element 6 (Fig. 1), a pre-compacted prepreg pack 9 of additional layers is successively molded one after another, layers of prepreg of the tract and non-duct shells 2, 5 are layered, bending them radially at an angle 90 ° to the tract and non-path shells 2.5 and removing the separation film 3 (Fig. 1), the pre-compacted package 10 of the prepreg from the additional layers is pressed axially by the forming ring 11 (Fig. 2). Clamp 7 (Fig. 1) is removed and the forming element 6 is fixed on the outer surface by winding glass 12 (Fig. 2), creating a closed volume. A drainage bag is assembled according to known technology and a vacuum-autoclave mode of curing the casing composite material is carried out at a temperature of 160 ° C. At this temperature, the elastically deformable material of the elastic forming element 6 (rubber) expands, working in a closed volume, which makes it possible to create uniform axial pressure during the entire curing mode on the laid out prepreg layers of the formed flange and in the annular direction on the layers of the tract and non-path shells, ensure satisfactory sealing of the flange prepreg package and sufficient interlayer contact pressure comparable to interlayer contact pressure m prepreg Traktovaya vnetraktovoy and shells of the casing. After curing, the casing is cooled, the drainage bag is dismantled and the flange is machined both at the end and in the areas of the pre-sealed packages of prepreg layers on the outer and / or inner side of the flange, eliminating damage to the structural part of the flange and loss of its mechanical strength.

According to this method, serial protective soundproofing housings for the PS 90A2 aircraft engine with flanges of various configurations are manufactured.

The proposed method, compared with the prototype, is more economical and less time-consuming to implement, it allows to produce large-sized products, both closed and open loop with flanges of various configurations and thicknesses with guaranteed mechanical strength of flange joints, reliability and quality of construction.

Claims (2)

1. A method of manufacturing a large-sized flange structure from layered polymer composite materials, including laying layers of the prepreg of the path and non-shell shells on the body of the forming tool with the formation of transverse flanges from the ends of the prepreg using the forming element, curing during heating, cooling, performing mechanical processing of the ends of the flanges with opening in them, the connecting holes, characterized in that when forming the flange as a forming element, a limited on the outer surface, a forming element with elastic elastically deformable properties, while on the structural part of the flange formed by the ends of the prepreg of the tract and non-path shells, on one and / or the other side, pre-packaged packages of additional layers of the prepreg are laid to create an allowance for the mechanical processing of the flange with the outer and / or the inner side of the flange, and molding is carried out under the influence of a temperature not lower than the expansion temperature of the elastically deformable material of the molding element. 2. A method of manufacturing a large-sized flange structure from layered polymer composite materials according to claim 1, characterized in that when forming a flange from layered composite materials having an angle of more than 0 degrees with respect to the path and non-path shells, in the process of laying out between the ends of the layers of the path prepreg and off-shell shells forming a flange, lay a separation film to prevent gluing of the layers of the prepreg, which has stickiness.

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