ES2393865B2 - METHOD FOR PLACING INSERTS IN COMPOSITE MATERIAL PARTS. - Google Patents

Abstract

Method of placing inserts in pieces of composite material, which consists of making a hole (2) with clearance in the application part (1) with respect to the shape of the insert (3) to be placed, placing on the insert (3) a shirt (4) woven with natural and / or synthetic fibers, to insert the insert (3) provided with the shirt (4), into the hole (2), applying a push pressure of the insert (3) inwards, while that in the gap between the insert (3) and the wall of the hole (2), resin is infused, which soaks the jacket (4) to fix the insert (3) on the wall of the hole (2).

Description

METHOD OF PLACING INSERTS IN COMPOSITE MATERIAL PARTS

Technical sector

The present invention is related to the incorporation of inserts in composite parts intended to support fasteners, for example, in the attachment of wind turbine blades to the bushing or in connecting elements between

sections

components from Pallas from wind turbine or

Applications

similar, proposing a method that

It allows

perform the placement from sayings inserts from

a

way precise Y reliable.

State of the art

Certain parts formed by composite materials, such as wind turbine blades, present considerable problems for transport in a single construction unit, so it is conventional to build them in sections that are transported separately and that are joined by assembly in the place of installation.

The joining of said component sections of pieces of composite materials is carried out conventionally by means of ties with threaded elements that are coupled with respect to inserts incorporated in the composite material of the parts to be joined.

The placement of the inserts for that purpose, is done conventionally by two methods, which

its about:

-

Adhesive inserts, making a hole in the composite material of the application piece, to then fix the insert by means of adhesive inside the hole. This method has the problem of the difficulty of obtaining a suitable filling with the adhesive between the surfaces of the insert and the hole. Solutions of this type are, for example, those of Patents ES 2274701 and EP 2138716.

-

Embedded inserts, placing the inserts between the laminate layers of the composite material during the manufacture of the application piece. This method has the problem that it forces discontinuities of the laminate of the composite material for adaptation to the shape of the insert, requiring a manual laminate with high manufacturing times in the area where the insert goes, where in spite of everything bags are produced resin. Solutions of this type are, for example, those of US Patents 2007243070, US 20110044817 and EP 2138716.

Object of the invention

According to the invention, a method is proposed that allows the insertion of inserts in the pieces of composite material after they have been manufactured, with characteristics that ensure in a practical way an optimal fixation of the inserts in their placement, saving the inconveniences of conventional methods

This method object of the invention consists in making in the piece of composite material a hole in correspondence with the shape of the insert to be placed, and in arranging on the insert to be placed, provided with

an axial through hole, a jacket of one or several dry reinforcement fabrics, woven unidirectionally, biaxially, triaxially or three-dimensionally, with natural fibers or synthetic fibers (such as glass fiber, carbon, aramid, boron, or any other similar material) or a combination thereof, the insert provided with said jacket being placed in the hole made in the application piece, where the insert is introduced with pressure, while resin is infused into the hole between the insert and the hole wall. which soaks the fabric shirt that unifies, reinforces and homogenizes the distribution of said resin in the hollow.

The insertion pressure of the insert into the placement hole can be carried out by means of a pushing force applied directly on the insert, by infusing the resin by injection into the gap between the insert and the hole wall, with exit breathing through a tube inserted in the axial through hole of the insert; or the infusion being carried out through the tube inserted in the axial through-trade of the insert, with exit breathing through the gap between the insert and the hole wall.

Bliss

Pressure from insertion of the insert in he

orifice

from placement may be done too

through

application from empty to through from a tube

introduced into the axial through hole of the insert, infusing the resin through the gap between the insert and the hole wall; or vice versa, that is by applying the vacuum through the gap between the insert and the hole wall, infusing the resin through the tube inserted in the hole

axial intern of the insert.

A method is thus obtained with which the following advantages are achieved:

-

The jacket that is placed on the insert positions the insert in the hole and maintains the manufacturing tolerance.

-The

infusion of the resin to through from the shirt from

cloth,

standardize Y homogenize the distribution from the

resin of

fixation to the along the insert

-

The resin-embedded fabric jacket acts as a bond between the composite material of the application piece and the insert, acting as a laminate layer of the composite material, thereby improving the mechanical properties of the joint.

-

The thickness of the joint between the insert and the composite material of the application piece can be precisely controlled.

-

It is not necessary to modify the laminate of the composite material of the application piece for the placement of the insert.

-

The method is automatable, allowing the placement of one or more inserts at the same time.

Therefore, the recommended method results from very advantageous characteristics, acquiring a life of its own and preferential character with respect to the conventional methods of the same function.

Description of the figures

Figure 1 shows a perspective scheme

Exploded placement of an insert according to the method of the invention.

Figure 2 is a sectional view of the placement of an insert by the method of the invention, according to a vacuum application embodiment.

The

figure 3 is a view in section from the

placement

from a insert through he method from the

invention,

according other realization from application from

empty.

Figure 4 is a sectional view of the placement of an insert by the method of the invention, according to an embodiment of application of a pushing force on the insert.

Figure 5 is a sectional view of the placement of an insert by the method of the invention, according to another embodiment of application of a pushing force on the insert.

Detailed description of the invention

The object of the invention relates to a method for placing inserts in the laminate of pieces of composite materials, with characteristics that improve the fixation of the insert with respect to the material of the application piece.

The recommended method is to perform in the

piece (1) of composite material of application a hole (2) corresponding to the shape of the insert (3) to be placed, but with clearance, and to arrange on the insert (3), partially or totally, a shirt (4 ) of one or more dry reinforcement fabrics, woven with natural fibers or synthetic fibers (such as fiberglass, carbon, aramid, boron, or any similar material), or a combination thereof, introducing the insert (3 ), thus wrapped in the hole (2), with an inward thrust pressure, while the gap between the surface of the insert (3) and the surface of the hole

(2) resin is infused.

In this way, the thrust pressure exerted adjusts the insert (3) with the sleeve (4) in the hole

(2), while the infused resin soaks the shirt (4), which unifies and homogenizes the

distribution of said resin between the surfaces of the insert (3) and the hole (2), so that the jacket

(4) soaked, it behaves like a laminate layer that determines an attachment of the insert (3) with optimal mechanical characteristics, when curing the resin.

To facilitate the entry of the resin and its extension through the gap between the insert (3) and the surface of the hole (2) 'in the formation of the insert (3) an axial through hole (5) is determined therethrough, placing in that axial through hole (5) a tube (6) that is sealed with respect to said axial through hole (5) by a bead of putty (7).

To determine the thrust pressure on the insert (3) into the hole (2) and the

Infusion of the resin through the jacket (4), a vacuum application system is provided, sealing the entrance of the gap between the insert (3) and the hole wall (2) with a waterproof cover (8) that is sealed with putty cords (9), through whose cover (8) there is a tube (10) that passes from the inside to the outside.

Thus, in relation to the tube (10) that passes through the cover (8) a resin tank (11) can be arranged connected, and through the tube (6) placed in the axial through hole (5) of the insert (3) apply a vacuum absorption, as shown in Figure 2; whereby an extraction of the air (12) contained in the gap between the insert (3) and the hole wall (2) takes place, resulting in an absorption that attracts the insert (3) into the hole (2) ) and that at the same time brings the resin from the tank (11) 'through the tube (10)' through the jacket (4) 'soaking it completely.

The application of the vacuum and the inlet of the resin can also be carried out in reverse, that is to say by applying the vacuum absorption through the tube (10) that passes through the cover (8) and the entrance of the resin through the tube (6) placed in the axial hole

(

5) of the insert (3), as shown in Figure 3; resulting in the same air extraction effect (12) and as a consequence the attraction of the insert

(

3) into the hole (2) and the resin drive through the jacket (4), as in the previous case.

The thrust pressure of the insert (3) towards the

inside the hole (2), it can also be made

applying

a force (13) since he Exterior on he

insert

(3), doing the introduction (14) from the

resin

by injection to through of the hole between he

insert (3) and the wall of the hole (2), producing the outlet (15) of the air contained in the gap between the insert (3) and the wall of the hole (2), through the tube (6) placed in the axial through hole (5) of the insert (3) as shown in Figure 4; or to introduce the resin (14) by injection, under the same conditions of direct thrust of the insert (3), through the tube (6) placed in the axial through trade

(5) of the insert (3), as shown in Figure 5; obtaining, in these cases an equivalent result, of insertion of the insert (3) into the hole (2), of infusion of the resin through the jacket (4) and outlet (15) of the air, as with the previous solutions of figures 2 and 3.

Claims (3)

1.-Method of placing inserts in pieces of composite material, characterized in that in the piece

(one)

of application, a hole (2) is made with clearance in relation to the shape of the insert (3) to be placed, being arranged on the insert (3), partially or totally, a sleeve (4) of one or more reinforcement fabrics dried, woven with natural or synthetic fibers or a combination thereof, to introduce the insert (3), provided with the jacket (4), into the hole (2) made in the piece (1), applying a pushing pressure of the insert (3) inwards, while in the gap between the insert (3) and the wall of the hole (2) resin is infused, which soaks the jacket (4) to establish by means of it the fixation of the insert (3) as a laminate layer; with a tube (6) that facilitates infusion of the resin through the jacket through the axial through hole (5) of the insert (3)

(4)

in said gap between the insert (3) and the hole wall (2).

2.-Method of placing inserts in pieces of composite material, according to the first claim, characterized in that the thrust pressure of the insert (3) into the hole

(2)

and the infusion of the resin through the jacket (4), is performed by vacuum application, the gap between the insert (3) and the hole wall (2) being sealed by a waterproof cover (8), through which disposes a tube (10), applying the vacuum through the tube (6) placed in the insert

(

3) and the resin inlet through the tube (10) that crosses the cover (8), or vice versa.

3.-Method of placing inserts in pieces of composite material, according to the first claim, characterized in that the thrust pressure of the insert (3) into the hole (2) is carried out by applying a force (13) since

he

Exterior on  he insert (3), introducing the

resin

by injection to through of the hole between he

insert

( 3) Y the wall of the orifice (2) , with exit

(fifteen)

of the air to through of the tube (6) ready in he

axial through hole (5) of the insert (3), or vice versa.