CN115592858A

CN115592858A - Composite material beam forming die and integrated forming preparation method thereof

Info

Publication number: CN115592858A
Application number: CN202211390774.0A
Authority: CN
Inventors: 刘永琪; 董志武; 李玉龙; 杨鹏; 侯博才
Original assignee: Changchun Changguang Aerospace Composite Material Co ltd
Current assignee: Changchun Changguang Aerospace Composite Material Co ltd
Priority date: 2022-11-07
Filing date: 2022-11-07
Publication date: 2023-01-13

Abstract

The invention provides a composite beam forming die and an integrated forming preparation method thereof, wherein the composite beam forming die comprises an upper plate, a bottom plate, an inner split group, an inner die and an outer die; the invention can meet the co-curing compression molding of a special-shaped beam consisting of a web plate, two side wing plates and a box-type structure, and the prepared composite beam has high dimensional precision, high internal and external surface gloss and internal quality and low manufacturing cost of the die.

Description

Composite material beam forming die and integrated forming preparation method thereof

Technical Field

The invention relates to the technical field, in particular to a composite beam forming die and an integrated forming preparation method thereof.

Background

The fiber reinforced thermosetting resin is widely applied to the advanced technical fields of aviation, aerospace and the like due to excellent mechanical properties such as high specific strength, high specific modulus and the like; in recent years, the requirement for lightweight of aerospace structural members is becoming more and more severe, and carbon fiber composite materials are gradually replacing metal materials to become main bearing structural materials of spacecrafts.

The composite material beam, the composite material frame and the like play important roles in reducing weight, bearing and stabilizing size of an elastic body structure and a space structure. At present, composite material beams are generally prepared by the following preparation processes:

(1) Autoclave and layering process. Due to the characteristic that the autoclave process uniformly pressurizes products, the process has the limitations of preparing a beam structure with a complex section and variable thickness, the dimensional precision is difficult to guarantee, and the manufacturing cost of a die is high.

(2) The RTM process. The process has high requirement on resin fluidity and low fiber volume content, and the prepared composite material is easy to have internal quality defects and is not suitable for the preparation process of the high-performance carbon fiber composite material.

(3) And (5) secondary assembly process. The process requires the drilling of holes in the surface of the already prepared composite material of the web and the wing plate, which reduces the performance of the composite material and requires a large amount of equipment for complex composite material beams.

(4) And (5) performing a press molding process. Due to the limitations of the pressing direction and the pressing sequence of the press, the process is only suitable for manufacturing the composite material beam with a simple structure.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a composite beam forming die and an integrated forming preparation method thereof, which can meet the co-curing compression molding of a special-shaped beam consisting of a web plate, two side wing plates and a box-type structure, and the prepared composite beam has high dimensional precision, high internal and external surface gloss and internal quality and low die manufacturing cost.

In order to realize the purpose, the invention adopts the following specific technical scheme:

the invention provides a composite material beam forming die which comprises an upper plate, a bottom plate, an inner split group, an inner die and an outer die, wherein the upper plate is fixedly connected with the bottom plate; the inner mold is fixed between the upper plate and the bottom plate, gaps for forming the composite beam are reserved among the inner mold, the inner mold and the inner valving group, and the inner mold and the outer mold, the outer mold is fixed on the outer side of the inner mold and fixedly connected with the upper plate and the bottom plate, and the inner valving group is fixed on the inner side of the inner mold and fixedly connected with the bottom plate.

Preferably, the upper plate, the bottom plate and the inner die are connected through screws and are positioned through positioning pins.

Preferably, a bottom plate spigot used for positioning the inner valving group is further formed on the bottom plate.

Preferably, the inner segments are fixed at an angle of 10 ° to each other, and the prepreg is pressurized by pressurizing the middle portion of the inner segment group to press the inner segments around outward.

Preferably, the material of the inner die and the inner split is aluminum alloy, and the material of the upper plate, the bottom plate and the outer die is 45-grade steel or Q235 steel.

Preferably, a pressurizing threaded hole for pressurizing is formed in the upper plate and the bottom plate.

Preferably, bolt through holes for connecting the inner die are formed in the upper plate and the bottom plate; and inner split bolt through holes used for connecting the bottom plate are formed in the inner split group.

The invention provides a composite material beam which comprises an outer wing plate, an inner wing plate, a web plate and a vertical rib, wherein two ends of the vertical rib are respectively and vertically connected with the inner wing plate and the outer wing plate, the web plate is vertically fixed with the vertical rib, and the composite material beam is divided into an upper layer and a lower layer by taking the web plate as a central line.

The invention provides an integrated forming preparation method for composite material beam forming, which comprises the following steps:

s1, preparing a composite material prepreg, and controlling the fiber volume content of the composite material prepreg to be 54-60%;

s2, preheating a forming mold, and laying a composite material prepreg on the inner mold after preheating, wherein the thickness of a laid layer for laying the composite material prepreg is 1 mm;

s3, after laying, manufacturing a vacuum bag, vacuumizing, and compacting the composite material prepreg;

s4, assembling the laid internal mold with the upper plate and the bottom plate, and laying composite material prepreg on the assembled upper plate and the assembled bottom plate, wherein the thickness of a laying layer for laying the composite material prepreg is 0.5 mm;

s5, after laying, assembling and pressurizing the upper plate and the bottom plate;

s6, after pressurization, laying composite material prepreg on the outer wing plate and the inner wing plate, wherein the thickness of a laying layer for laying the composite material prepreg is 1.5 mm;

s7, after paving, assembling the outer mold and the inner valve section group, and integrally closing the mold;

s8, preheating the forming die and the composite material prepreg, and carrying out hot die assembly, wherein the preheating time and the preheating temperature are 90 ℃/2h;

s9, after hot die assembly, putting the forming die into a curing furnace for heating and carrying out integral forming and co-curing, wherein the curing system is set to be 120 ℃/2 h-150 ℃/2 h-190 ℃/2h;

and S10, demoulding to obtain the composite material beam.

Preferably, the reinforcement of the composite material prepreg is T700-grade and/or T800-grade carbon fiber, and the matrix material of the composite material prepreg is cyanate resin or bismaleimide resin or epoxy resin.

The invention can obtain the following technical effects:

1. the forming die is simple in overall structure, and can meet co-curing compression molding of the special-shaped beam formed by the web, the wing plates on the two sides and the box-type structure.

2. The product prepared by adopting the integral forming method has no internal and external quality defects, and has high vertical bars and high dimensional accuracy of internal and external outlines; the inner contour has no quality problems of bridges, cavities, dispersive defects and the like, and is suitable for preparing small-batch beams with complex structures.

3. The production period can be obviously shortened while the product quality is ensured by adopting an integrally forming process method.

4. The forming die has simple structure and low manufacturing cost; the problem of high die cost or material performance damage caused by secondary assembly process when the autoclave process is used for manufacturing complex frame and beam structures is solved.

Drawings

Fig. 1 is a sectional view of a composite beam forming die provided according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an inner split provided according to an embodiment of the present invention.

Fig. 3 is an assembly view of an inner mold and an upper plate according to an embodiment of the present invention.

Fig. 4 is an assembly diagram of an inner mold and a bottom plate according to an embodiment of the present invention.

Fig. 5 is an assembly view of a base plate and an upper plate provided according to an embodiment of the present invention.

Fig. 6 is an isometric view of a composite beam provided in accordance with an embodiment of the present invention.

FIG. 7 is a cutaway view of a composite beam provided in accordance with an embodiment of the present invention.

Fig. 8 is a flowchart of a method for integrally forming a composite beam according to an embodiment of the present invention.

FIG. 9 is a schematic illustration of a composite material Liang Puceng provided in accordance with an embodiment of the present invention.

Wherein the reference numerals include: the composite material beam comprises an upper plate 1, a bottom plate 2, a bottom plate spigot 21, an inner split group 3, an inner split 31, an inner die 4, an outer die 5, a pressure threaded hole 6, a bolt through hole 7, an inner split bolt through hole 8, a composite material beam 9, an outer side wing plate 91, an inner side wing plate 92, a web plate 93 and studs 94.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same blocks. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

The embodiment of the invention comprises three parts, namely a composite beam forming die, a composite beam and a composite beam integrated forming preparation method.

The first part is a composite material beam forming die:

fig. 1 shows a cross-sectional structure of a composite beam forming mold according to an embodiment of the present invention.

As shown in fig. 1, a composite beam forming mold provided by an embodiment of the present invention includes an upper plate 1, a bottom plate 2, an inner split group 3, an inner mold 4 and an outer mold 5; the inner mold 4 is fixed between the upper plate 1 and the bottom plate 2, a gap for forming the composite material beam 9 is reserved between the inner molds 4, the outer mold 5 is fixed on the outer side of the inner mold 4 and fixedly connected with the upper plate 1 and the bottom plate 2, and the inner split group 3 is fixed on the inner side of the inner mold 4 and fixedly connected with the bottom plate 2.

The bottom plate 2 is further provided with a bottom plate spigot 21 for positioning the inner valving group 3.

The outer die 5 is made of No. 45 steel or Q235 steel, and the prepreg can be further pressurized in the curing process by utilizing the difference of thermal expansion coefficients of aluminum alloy and steel

Fig. 2 shows an internal valving structure provided by an embodiment of the present invention.

As shown in fig. 2, the number of the inner petals 31 in the inner petal set 3 is at least two, in the embodiment provided by the present invention, the fixed angle between the inner petals 31 is 10 °, and the inner petal set 3 is triangular; an inner split bolt through hole 8 used for being connected with the bottom plate 2 is formed in the inner split group 3.

For the composite material product surface which needs to be pressurized from inside to outside and has a narrow space, the vertical pressurizing mode is difficult to use, so the inner pressurizing mold is set into the form of the inner valving group 3, a certain angle is arranged between each valving, the number of the inner valving 31 and the angle between the inner valving 31 in the inner valving group 3 can be adjusted according to the actual pressurizing requirement, theoretically, the angle is more than 0 degree, but in the actual operation process, in order to comprehensively consider the force transmission and the space where the inner valving 31 can be placed, the angle is usually set to 10 degrees, and the requirement can be met.

Through the design of the inner split group 3 mould, the inner split 31 at the central part can be pressed downwards in the mould closing process, the inner splits 31 at the periphery are indirectly extruded outwards, and then the prepreg is pressed.

The number of the inner split groups 3 provided by the embodiment of the invention is preferably five inner splits 31, the five inner splits 31 are sequentially assembled according to a fixed angle, and demoulding is carried out by taking 10 degrees as a demoulding angle; the external dimension of the assembled inner split group 3 is consistent with the inner cavity dimension of the inner die 4, and the inner split group 3 can be installed to pressurize the inner side wing plate 92 of the composite beam 9, so that the accuracy of the inner dimension is improved.

The material of the inner die 4 and the inner segment 31 is preferably an aluminum alloy because considering that the coefficient of thermal expansion of the aluminum alloy is much larger than that of steel, the size of the cavity is reduced during the product curing process, which facilitates the pressurization of the studs 94.

Fig. 3 is an assembly diagram of the inner mold and the upper plate according to the embodiment of the present invention.

Fig. 4 is an assembly diagram of the inner mold and the bottom plate according to an embodiment of the present invention.

As shown in fig. 3-4, the upper plate 1, the bottom plate 2 and the inner mold 4 are connected by screws, and are positioned by positioning pins after the connection.

The material of the upper plate 1 and the bottom plate 2 is No. 45 steel or Q235 steel.

As shown in fig. 5, a pressurizing threaded hole 6 for pressurizing and a bolt through hole 7 for connecting the inner mold 4 are opened in the upper plate 1 and the bottom plate 2.

The second part is a composite beam:

figure 6 is an isometric view of a composite beam provided in accordance with an embodiment of the present invention.

As shown in fig. 6, the composite beam 9 includes an outer wing plate 91, an inner wing plate 92, a web 93, and a stud 94, wherein both ends of the stud 94 are respectively vertically connected to the inner wing plate 92 and the outer wing plate 91, and the web 93 is vertically fixed to the stud 94.

As shown in fig. 7, since the web 93 is vertically fixed to the studs 94, the composite beam 9 is divided into an upper layer and a lower layer by taking the web 93 as a center line.

The third part is a method for integrally forming and preparing the composite material beam:

As shown in fig. 8, an embodiment of the present invention further provides an integrated molding preparation method for a composite beam molding mold, including the following steps:

the reinforcement of the composite material prepreg is T700-grade and/or T800-grade carbon fiber, and the matrix material of the composite material prepreg is cyanate resin or bismaleimide resin or epoxy resin.

S2, preheating the forming mold, laying composite material prepreg on the inner mold 4 after preheating, wherein the thickness of a laid layer for laying the composite material prepreg is 1 mm;

the composite material prepreg is laid in a U shape and laid on the surface of the composite material beam 9.

s4, assembling the laid inner mold 4 with the upper plate 1 and the bottom plate 2, and laying composite material prepreg on the assembled upper plate 1 and the assembled bottom plate 2, wherein the thickness of a laying layer for laying the composite material prepreg is 0.5 mm;

s5, after paving, assembling and pressurizing the upper plate 1 and the bottom plate 2;

s6, after pressurization, laying composite material prepreg on the outer wing plate 91 and the inner wing plate 92, wherein the thickness of a laying layer for laying the composite material prepreg is 1.5 mm;

FIG. 9 shows a schematic diagram of composite material Liang Puceng provided by an embodiment of the present invention.

As shown in fig. 9, the lay-up of the composite beam 9: the first U-shaped laying is carried out, the thickness of the laying layer is 1 mm, the second integral laying is carried out, the thickness of the laying layer is 0.5 mm, the wing plates on the two sides are laid for the third time, and the thickness of the laying layer is 1.5 mm.

S7, after paving, assembling the outer mold 5 and the inner split group 3, and integrally closing the mold;

and S10, demoulding to obtain the composite material beam 9.

The size of the composite beam 9 of the embodiment of the present invention is: the stud 94 is 2mm thick, the outside flap 91 is 3mm thick, the inside flap 92 is 3mm thick, and the web 93 is 3mm thick.

The cross section of the composite beam 9 is H-shaped, so the composite beam 9 is a symmetrical structure with respect to the H-section and with the middle plane of the web 93, and the inner and outer contours of the composite beam 9 are triangular. The outer contour dimension is 650 × 750 × 100 mm, and the inner contour dimension is: 350X 420X 100 mm.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. The composite material beam forming die is characterized by comprising an upper plate (1), a bottom plate (2), an inner split group (3), an inner die (4) and an outer die (5); centre form (4) are fixed upper plate (1) with between bottom plate (2), between centre form (4) with interior split group (3) centre form (4) with leave the space that is used for shaping combined material roof beam (9) between external mold (5), external mold (5) are fixed the outside of centre form (4) and with upper plate (1) with bottom plate (2) fixed connection, interior split group (3) are fixed the inboard of centre form (4) and with bottom plate (2) fixed connection.

2. The composite beam forming die of claim 1, wherein the upper plate (1), the bottom plate (2) and the inner die (4) are connected through screws and are positioned through positioning pins.

3. The composite material beam forming die according to claim 1, wherein a bottom plate spigot (21) for positioning the inner valving group (3) is further formed on the bottom plate (2).

4. The composite beam forming die of claim 1, wherein the number of the inner segments (31) is at least two, the inner segments (31) are fixed at an angle of 10 ° to each other, and the inner segment group (3) is triangular.

5. The composite beam forming die of claim 4, wherein the inner die (4) and the inner split (31) are made of aluminum alloy, and the upper plate (1), the bottom plate (2) and the outer die (5) are made of No. 45 steel or Q235 steel.

6. The composite beam forming die of claim 1, wherein a pressure threaded hole (6) for pressurizing is formed on the upper plate (1) and the bottom plate (2).

7. The composite material beam forming die of claim 1, wherein bolt through holes (7) for connecting the inner die (4) are formed on the upper plate (1) and the bottom plate (2); and an inner split bolt through hole (8) used for connecting the bottom plate (2) is formed in the inner split group (3).

8. The composite beam is characterized in that the composite beam (9) comprises an outer wing plate (91), an inner wing plate (92), a web plate (93) and studs (94), two ends of each stud (94) are respectively and vertically connected with the inner wing plate (92) and the outer wing plate (91), the web plate (93) is vertically fixed with the studs (94), and the composite beam (9) is divided into an upper layer and a lower layer by taking the web plate (93) as a central line.

9. An integrated molding production method for molding a composite beam by using the composite beam as claimed in claim 8, comprising the steps of:

s2, preheating the forming die, laying the composite material prepreg on the inner die (4) after preheating, wherein the thickness of a laid layer for laying the composite material prepreg is 1 mm;

s3, after paving, manufacturing a vacuum belt, vacuumizing, and compacting the composite material prepreg;

s4, assembling the laid inner mold (4) with the upper plate (1) and the bottom plate (2), and laying the composite material prepreg on the assembled upper plate (1) and the assembled bottom plate (2), wherein the thickness of a laid layer for laying the composite material prepreg is 0.5 mm;

s5, after paving, assembling and pressurizing the upper plate (1) and the bottom plate (2);

s6, after pressurization, laying the composite material prepreg on the outer wing plate (91) and the inner wing plate (92), wherein the thickness of a laid layer for laying the composite material prepreg is 1.5 mm;

s7, after paving, assembling the outer mold (5) and the inner split group (3), and integrally assembling the molds;

and S10, demoulding to obtain the composite material beam (9).

10. The method for integrally forming the composite beam forming die according to claim 8, wherein the reinforcement of the composite prepreg is T700-grade and/or T800-grade carbon fiber, and the matrix material of the composite prepreg is cyanate resin, bismaleimide resin or epoxy resin.