Method for manufacturing wind turbine blades, blades for propellors, wings, or similar structures, and structure in the form of a blade obtained by means of this procedure

Abstract

The invention relates to a method for manufacturing wind turbine blades, blades for propellers, wings or similar structures, and to a structure in the shape of a blade produced by means of said method, including: use a female mold of the leading edge ( 5 ), a female mold of the trailing edge ( 6 ), and a third mold ( 7 ) for a composite male tool ( 8 ) as a lost mold for manufacturing at least an inner crossbeam ( 4 ); wherein a demolding agent and an outer protective varnish is applied on the inner sides by robot or a digitally-controlled device; applying prepreg in superimposed layers; coating the prepreg with a vaccum film, and connecting to a pump for extracting air from between the prepreg layers; fitting together the molds and positioning the pieces with the prepreg laminates; and applying pressure and thermal curve for the method of curing or polymerizing the set of pieces in a single stage or all at once.

1 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, of the type of structures ( 1 ) that have a configuration which presents a leading edge and a trailing edge, characterized in that it comprises:
 the use of a female mould of the leading edge ( 5 ) to manufacture a leading edge piece ( 2 ), a female mould of the trailing edge ( 6 ) to manufacture a trailing edge piece ( 3 ), and a third mould ( 7 ) with which a male jig ( 8 ) made from composite is obtained that acts as a lost mould  15  to manufacture at least one inner structural side member ( 4 );   surface treatment with a demoulding agent of the inner faces of the aforesaid female moulds of the leading edge ( 5 ) and of the trailing edge ( 6 ) as in any composites process, applied automatically with a robot or numerical control machine and, once the demoulding agent is dry, application similarly in an automated manner with a robot of a varnish that will be the outer protector of the structure ( 1 );   application of the prepreg material in superimposed layers, according to a previously calculated sequence, one-dimensional, a veil, biaxial, triaxial etc.;   coverage of the prepreg laminates with a vacuum film, proceeding then to connect them to a pump for the removal of the possible air occluded between the laminates and improve compaction between the layers of prepreg;   engagement of the female moulds of the leading ( 5 ) and of the trailing ( 6 ) edges and positioning of the pieces with the prepreg laminates;   application of a light pressure on the assembly, to assist contact between the prepreg laminate parts, and subjected to a thermal curve for the process of curing or polymerization of the assembly of said pieces in one and the same stage or strokes,   
     
     
         2 . PROCEDURE FOR THE MANUFACTURE OF wind turbine blades, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that the male jig ( 8 ) that acts as a lost mould for making the structural side member ( 4 ) is either C- or closed-box or double-T shaped. 
     
     
         3 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that the prepreg material in superimposed layers is applied in the form of fabrics or tapes, which may be glass, carbon, aramides, hybrids, kevlar, thermoplastics, nanotubes, impregnated with vinyl ester resin, epoxy, PP, PET, amongst others of variable composition variable, in gram weights that may range from 500 g/m2 to 2000 g/m2 and present a variable configuration. 
     
     
         4 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that support pieces are placed in the moulds as additional shims, right in the angle of the leading edge or in the angle of the trailing edge to seek the end form of the blade or structure, or else inserted between the layers of prepreg, or to mark and fix the position of the superimposed multi-layers of prepreg. 
     
     
         5 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 4 , characterized in that the support pieces are made from synthetic foam, balsa or honeycomb core. 
     
     
         6 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that on the vacuum film strips of “peelable fabric” are incorporated on the parts of the prepreg sheet that are going to be in direct contact with one another, which are removed at the time of joining up the pieces of the structure ( 1 ) with one another. 
     
     
         7 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that, in order to assist the correct positioning of the side members ( 4 ) between the inner surfaces of the prepregs of the leading ( 2 ) and trailing ( 3 ) edge pieces, the numerical control machine or robot marks on said prepregs the exact area with a ridge ( 9 ) for instance. 
     
     
         8 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that the female moulds of the leading ( 5 ) and of the trailing ( 6 ) edges are metallic, executed with a plate which has metal reinforcing brackets ( 5   a  and  6   a ) welded on the outer side. 
     
     
         9 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that the female moulds of the leading ( 5 ) and of the trailing ( 6 ) edges are provided on their outer side with a heating system to achieve the curing of the prepreg sheets that eventually reaches a temperature of up to 150° C. 
     
     
         10 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to claim,  1 , characterized in that in certain areas the female moulds of the leading ( 5 ) and of the trailing ( 6 ) edges present holes which on the outer side of the mould are communicated with hoses that in turn permit connection to a compressor. 
     
     
         11 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that prior to polymerization of the prepreg sheets, a flow of hot air is applied both from inside and outside at the same time. 
     
     
         12 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that when polymerization is completed a flow of cold air is applied to speed up demoulding. 
     
     
         13 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 7 , characterized in that the female mould of the leading edge ( 5 ) incorporates rotary fins ( 10 ) that permit the depositing of the prepreg sheets inside the mould marking the ridge ( 9 ). 
     
     
         14 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 1 , characterized in that the female mould of the trailing edge ( 6 ) is made up of two parts jointed by means of a hinge ( 11 ), which permits the folding-back movement of said pieces to form the mould. 
     
     
         15 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 14 , characterized in that in the female of the trailing edge ( 6 ) the prepreg laminating process  20  is carried out first of all with the mould deployed, and a number of longitudinal prepreg tapes or strips are deposited right on the hinge ( 11 ) in order to strengthen and consolidate this area. 
     
     
         16 . BLADE-LIKE STRUCTURE, obtained by means of a procedure as described in  claim 1 , characterized in that this is made up of a piece forming a leading edge ( 2 ), a piece forming a trailing edge ( 3 ) and at least one piece forming an inner reinforcing side member ( 4 ); in that said pieces are made from sheets of prepreg material joined together by means of a single thermal curing step and forming an integral body with no bonded parts. 
     
     
         17 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 2 , characterized in that the prepreg material in superimposed layers is applied in the form of fabrics or tapes, which may be glass, carbon, aramides, hybrids, kevlar, thermoplastics, nanotubes, impregnated with vinyl ester resin, epoxy, PP, PET, amongst others of variable composition variable, in gram weights that may range from 500 g/m2 to 2000 g/m2 and present a variable configuration. 
     
     
         18 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 2 , characterized in that support pieces are placed in the moulds as additional shims, right in the angle of the leading edge or in the angle of the trailing edge to seek the end form of the blade or structure, or else inserted between the layers of prepreg, or to mark and fix the position of the superimposed multi-layers of prepreg. 
     
     
         19 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 3 , characterized in that support pieces are placed in the moulds as additional shims, right in the angle of the leading edge or in the angle of the trailing edge to seek the end form of the blade or structure, or else inserted between the layers of prepreg, or to mark and fix the position of the superimposed multi-layers of prepreg. 
     
     
         20 . PROCEDURE FOR THE MANUFACTURE OF WIND TURBINE BLADES, PROPELLER BLADES, WINGS OR SIMILAR STRUCTURES, according to  claim 2 , characterized in that on the vacuum film strips of “peelable fabric” are incorporated on the parts of the prepreg sheet that are going to be in direct contact with one another, which are removed at the time of joining up the pieces of the structure ( 1 ) with one another.