System for forming stacks of composite materials

Abstract

The system for forming stacks of composite materials comprises a form (1) which defines the section that is desired to provide to a stack (2) of composite material placed thereon to obtain a formed stack (2); a counter-form (3), which together with the form (1), forms and obtains the formed stack (2); and it is characterized in that the system also comprises transition elements (4) deformable, that adopt a variable section from an initial section in one of its ends and the end section defined by the form (1) in the other end. It allows changing the geometry during the forming of the laminate, to obtain laminates of variable section along its length. For this purpose, the form and counter-form must have a variable geometry at will.

Claims

1. A system for forming stacks of composite materials, the system comprising: a form which defines a section that is desired to provide to a stack of composite material placed thereon to obtain a formed stack; a counter-form, which together with the form, forms and obtains the formed stack; and a plurality of deformable transition elements, that adopt a variable section from an initial section in one of its ends and an end section defined by the form in the other end, wherein the transition elements are positioned above and below the stack of composite material, defining a nozzle, flexible and adaptable to different geometries, that is configured to move relative to the stack of composite material such that it generates by friction a traction which frictionally tightens the stack.

2. System for forming stacks of composite materials according to claim 1, wherein said counter-form or said stack of composite material or said transition elements are movable longitudinally along the system.

3. System for forming stacks of composite materials according to claim 1, wherein said transition elements provide heat.

4. System for forming stacks of composite materials according to claim 1, wherein said counter-form is adaptable.

5. System for forming stacks of composite materials according to claim 4, wherein said counter-form consists of a flexible container.

6. System for forming stacks of composite materials according to claim 5, wherein said flexible container, forming the counter-form, comprises a filler.

7. System for forming stacks of composite materials according to claim 6, wherein said filler is a plurality of particles.

8. System for forming stacks of composite materials according to claim 1, wherein said transition elements are formed by membranes or tissues.

9. System for forming stacks of composite materials according to claim 1, wherein said form is of varying cross section along its length.

10. System for forming stacks of composite materials according to claim 1, wherein said transition elements consist of a plurality of rods or a plurality of longitudinal plates.

11. System for forming stacks of composite materials according to claim 10, wherein the form and the counter-form are formed by supports placed in one of the ends of said rods.

12. System for forming stacks of composite materials according to claim 11, wherein said rods are positioned below said stack of composite material.

13. System for forming stacks of composite materials according to claim 11, wherein said rods are placed above said stack of composite material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to complement the description being made and with the aim to help better understanding of the characteristics of the invention, are attached as a part of said description, a set of drawings wherein by way of illustration and not limiting, has been represented the following:

(2) FIGS. 1 to 3 are perspective views of the system for forming stacks of composite materials of the present invention as a first embodiment, which represent the stages of forming a stack;

(3) FIG. 4 is a perspective view of a variant of the system for forming stacks of composite materials of the present invention, as an alternative of said first embodiment;

(4) FIGS. 5 to 7 are perspective views of the system for forming stacks of composite materials of the present invention according to a second embodiment, which represent the stages of forming a stack;

(5) FIG. 8 is a perspective view of a variant of the system for forming stacks of composite materials of the present invention, according to an alternative of said second embodiment;

(6) FIGS. 9 to 12 are perspective views of the system for forming stacks of composite materials of the present invention, according to a third embodiment, which represent the stages of forming a stack.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

(7) In FIGS. 1 to 3 is shown a first embodiment of the system for forming stacks of composite materials according to a first embodiment.

(8) According to this first embodiment, the system of the present invention comprises a form 1, for example an elongated mandrel 1. This form 1 has a complex geometry, for example a ?-shaped, that is the one that wants to be provided to a stack 2 of composite material, which is placed on said form 1 (right side of FIGS. 1 to 3).

(9) The system of the present invention also comprises the transition elements 4, which can provide heat. The function of these transition elements 4 is to define a nozzle flexible and adaptable to different geometries.

(10) In the case of providing heat, they also have the function of heating the stack 2 and pre-forming it. Said stack may comprise different types of materials, such as thermoset materials, which are formed at a temperature of about 80? C., and/or thermoplastic materials, which are formed at a temperature of about 300? C.

(11) Said transition elements 4 are placed in this case above and below the stack 2, and can be formed by membranes or tissues, but may be placed only above or below. In the embodiment shown, these transition elements 4 are tissues, for example, thermal blankets.

(12) Must be noted that it is important that the transition elements 4 are adaptable, meaning that they can be adapt to the shape defined by the form 1.

(13) The system to the present invention also comprises a counter-form 3, which in this embodiment is also flexible or adaptable, i.e. also adapts to the shape defined by said form 1.

(14) According to this first embodiment, said counter-form 3 is composed of a container, such as a bladder, which can contain a filler, such as particles, lead shots, magnetic particles, or pressurized air, or a combination thereof. The function of said filler of particles is to allow a better adaptation of counter-form 3 to the complex shape defined by the form 1, particularly if small radii dimensions are defined. Must be noted that the dimensions of the particles, if any, will correspond to said complex shape.

(15) In the embodiment shown, said counter-form 3 is movable along the form 1 as shown in FIGS. 1 to 3.

(16) The process of forming the stack 2 is as follows:

(17) Firstly (FIG. 1), the stack is placed on the form 1 longitudinally, being the transition elements 4 positioned above and below said stack 2, providing to the stack 2 a proper temperature for heating and preforming, in such a case.

(18) Said transition elements 4, in addition must be sufficiently tensed to avoid wrinkles occur and to adapt perfectly to the shape defined by the form 1. The initial geometry is given by two flat steel plates 5, placed at the front of the transition elements.

(19) Once said stack 2 is at the appropriate temperature, (FIG. 2) the counter-form 3 is moved along the form 1 in the direction shown by the arrow in FIG. 3. When the counter-form is placed on the transition elements it presses their ends against the form, and requires them to adopt its geometry, thus being formed the transition nozzle with the end of the stack, threaded thereon, as shown in FIG. 2. Thus is been conformed the transition nozzle with the end of the laminate 2 inside, and also conformed the transition of this and the threaded in the nozzle.

(20) Then, the set that forms the nozzle is moved along the stack and the mandrel to form the stack along all its length (2), as presented in FIG. 3.

(21) In FIG. 4 has been represented a variant of this first embodiment, in which the form 1 is from variable section. In this case, when the transition elements 4 and the counter-form 3 are moved along the form, the transition elements 4 are changing too their section along its length, thanks to its flexible or adaptable nature, and will form the laminate 2, adapting them to the different sections of the form 1 in all its length, as well to the curves that it presents.

(22) In the FIGS. 5 to 7 is represented a second embodiment from the system of the present invention. For simplicity, in the description of this embodiment, are used the same reference numerals to designate equivalent elements.

(23) In comparison to the first embodiment, here the nozzle defined by the transition elements 4, which are blankets too, the form 1 and the counter-form 3 remain static, and is pulled the laminate 2 which passes through the nozzle, so that, it enters flat-shaped from one side and leaves formed of the other side.

(24) The end of the laminate 2 is disposed between the two transition elements 4, still flat, and they are heated so that is also heated the laminate 2. Then, the rear end of the transition elements 4 is confined, being pressed between the form 1 and the counter-form 3.

(25) Thus, the transition nozzle is configured with the end of laminate 2 inside and the transition also conformed in the laminate 2. Then, the laminate 2 is pulled to pass it through the nozzle in this way formed so that it is being warmed and formed.

(26) In FIG. 8 it has been represented a variant of this embodiment, in which the cross section of form 1 and counter-form 3 is variable.

(27) In FIGS. 9 to 12 is represented a third embodiment of the system of the present invention. For simplicity, in the description of this embodiment, are used the same reference numerals to designate equivalent elements.

(28) In this embodiment, the transition elements 4 are formed by a plurality of longitudinal rods, and said rods are considered that form a flexible nozzle, since their relative position can be varied between them vertically and transversally, as can be seen in the figures. Also in this case, must be indicated that the rods will have a diameter suitable to perfectly adapt to the shape defined by the form 1 and the counter-form 3.

(29) In this third embodiment, the form 1 and counter-form 3 are formed by supports located at one of the ends of said rods, being the supports of the form 1 below the laminate 2, and the supports of the counter-form 3 above the laminate 2.

(30) As shown by the arrows in FIG. 12, said supports are movable vertically and transversally to define the section of the laminate 2 that is desired.

(31) In this third embodiment, as in the second embodiment, the forming of the laminate 2 is carried out pulling from the same laminate 2, as indicated by the arrow in the FIG. 11.

(32) In view of this description and set of figures, an expert in the art will understand that embodiments of the invention that have been described can be combined in multiple ways within the object of the invention. The invention has been described according to some preferred embodiments thereof, but for an expert in the art will be evident that multiple variations can be introduced in said preferred embodiments without exceeding the object of the claimed invention.