A process for solving R corner defects of carbon fiber composite wall

Abstract

The present application belongs to the field of aviation composite material processing technology, and discloses a process method for solving R-angle defects in carbon fiber composite material walls, including the following steps: step one, making a composite base plate; step two, making a C-type cover plate; first, making a C-type cover plate forming mold; then, pasting the C-type cover plate; step three, producing the wall. A positioning ear is set at one end of the C-type cover plate; a positioning screw sleeve is set on the forming mold 1. The base plate tooling of the present application is changed from Q235 material to a composite material, which has good corrosion resistance and high reuse rate. It can effectively perform thermal deformation with the shape of the product while ensuring strength; a cover plate consistent with the product profile is added to the C-type area; the pressure in the product area is made consistent, and the parts on the vacuum bag side also obtain the same surface quality as the mold side; the conventional molding method of the J-type wall solves the problem that there are pores or delamination in the non-destructive detection of the R-angle area of ​​the product; the base plate tooling has poor thermal deformation and uneven pressure in the base plate area.

Description

Technical Field

[0001] The present application relates to a process for solving R-angle defects of a carbon fiber composite material wall, and belongs to the technical field of aviation composite material processing. Background Art

[0002] With the improvement of aviation technology and aircraft flight speed, higher requirements are placed on the strength of the wings, so the strength and quality requirements for the reinforced walls in the wings are more stringent.

[0003] At present, the main structure of the reinforced wall in the wing is a J-shaped wall. The conventional molding method is to first mold the Z, lay the bottom plate, and then lay the C-shaped. All molding molds are metal molds, and the material is Q235. The main scheme is as follows: clean the mold, lay 8 layers of Z-shaped prepreg on the main body of the molding mold; lay 8 layers of prepreg on the bottom plate tooling, and then combine the bottom plate with prepreg with the main body tooling, and the bottom plate tooling is supported on the back; after the bottom plate tooling is combined with the main body tooling, the remaining 8 layers of C-shaped wall are laid; the surface is laid with skinning cloth, isolation film, and vacuum bag, and after the vacuum test is qualified, it is put into the can for curing; take out of the oven, open the mold, and test.

[0004] The above solution has the problem that the product R corner area has pores or delamination in the non-destructive testing; the bottom plate tooling has poor thermal deformation and the pressure in the bottom plate area is uneven. This solution has poor non-destructive testing results, high product porosity, and large single defect diameter. Summary of the invention

[0005] In order to solve the problems that the conventional forming method of J-shaped walls has pores or delamination in the R corner area of ​​the product during non-destructive testing; the thermal deformation of the bottom plate tooling is poor, and the pressure in the bottom plate area is uneven, the present application provides a process method for solving the R corner defects of carbon fiber composite material walls.

[0006] The technical solution adopted in this application:

[0007] A process for solving R corner defects of carbon fiber composite wall, characterized by comprising the following steps:

[0008] Step 1: Making a composite base plate;

[0009] First, QY260 / EW100 high temperature curing material, i.e. glass cloth prepreg with bismaleimide resin matrix is ​​used to replace Q235 ordinary carbon structural steel material used in the prior art to produce a composite base plate, the size of which is consistent with the size of the existing base plate tooling; then, the edge of the composite base plate is cut to retain the required size of the wall and the axial positioning position with the main tooling;

[0010] Step 2: Make a C-shaped cover;

[0011] First, make a C-type cover plate forming mold: the C-type cover plate forming mold is made of prepreg consistent with the product, and the inner surface of the C-type cover plate forming mold is consistent with the C-type area of ​​the wall. The inner surface of the C-type area of ​​the wall is extracted as the outer surface of the C-type mold. The inner surface of the C-type cover plate forming mold is consistent with the inner surface of the C-type area of ​​the wall. The C-type cover plate forming mold is processed by a metal mold; secondly, lay layers on the C-type cover plate forming mold, lay auxiliary materials for curing; cut according to the cover plate cutting line to retain the effective area; thirdly, paste the C-type cover plate: lay a layer of adhesive demoulding cloth on the surface of the C-type cover plate forming mold, and the adhesive side is bonded to the C-type cover plate forming mold; lay 2 layers of unvulcanized silicone rubber and 2 layers of carbon fiber fabric consistent with the product material, as well as 2 layers of unvulcanized silicone rubber in the C-type cover plate forming mold; then, lay the auxiliary materials into the tank for curing to form a C-type cover plate; then, demould and cut the C-type cover plate so that the size of the C-type cover plate is consistent with the size of the wall;

[0012] Step 3: Produce wall;

[0013] First, the mold is cleaned and eight layers of Z-shaped prepreg are laid on the molding mold to form the main tooling;

[0014] Then, 8 layers of straight prepreg are laid on the bottom plate to form a bottom plate tooling, which is supported at the back. After the bottom plate tooling is combined with the main body tooling, 8 layers of C-type prepreg are laid on the wall.

[0015] After that, after the plying is completed, lay the peeling cloth and isolation film on the wall surface, and then place the C-type cover; after laying the gas-conducting medium on the C-type cover, paste the vacuum bag and put it into the tank for curing.

[0016] Finally, it is taken out of the oven, demolded and tested.

[0017] Furthermore, a positioning ear is provided at the wider end of the C-shaped cover plate, and a positioning hole is pre-set on the positioning ear; a positioning screw sleeve is provided at a position corresponding to the positioning hole on the molding die of the main tooling to fasten the positioning hole on the positioning ear.

[0018] Furthermore, the positioning holes are pre-set on the positioning ears. Initial hole, then expanded to Positioning holes.

[0019] Furthermore, the positioning screw sleeve is replaced by a positioning pin for fastening the positioning hole on the positioning ear.

[0020] Furthermore, in the production of the composite base plate, 50 layers of QY260 / EW100 high temperature curing material, i.e. glass cloth with a bismaleimide resin matrix, are laid on the base plate tooling; the thickness of a single layer of QY260 / EW100 high temperature curing material after curing is 0.09 mm, and the thickness of the composite base plate after curing is 4.5 mm, which meets the wall requirements.

[0021] Furthermore, the material of the bottom plate 2 is consistent with the material of the wall.

[0022] Furthermore, in the production of the composite base plate, 25 layers of base plate material consistent with the wall material, namely carbon cloth, are laid on the base plate tooling. The single layer thickness of the carbon cloth is 0.125 mm, and the thickness of the 25 carbon cloth base plate after curing is 3.2 mm, which meets the wall requirements.

[0023] Furthermore, the thickness of the C-shaped cover plate forming die is 5 mm.

[0024] Furthermore, the C-shaped cover plate forming mold is a concave mold, the inner surface of which is consistent with the inner surface profile of the C-shaped area of ​​the wall, and the size exceeds the single side of the wall by 30-50 mm.

[0025] This application has the following beneficial effects:

[0026] The base plate tooling of the present application is changed from Q235 material to composite material. The composite tooling has good corrosion resistance and high reuse rate. It can effectively undergo thermal deformation according to the shape of the product while ensuring strength. Compared with metal tooling, composite tooling does not need to be polished or coated with release agent after each use. Production can be achieved by sticking a release cloth with adhesive, which improves mold preparation efficiency and reduces production costs. After the overall laying is completed, a cover plate consistent with the product profile is added to the C-shaped area, so that the pressure can be evenly transferred to the product area, so that the pressure in the entire product area is consistent, and the parts obtain the same surface quality on the vacuum bag side as on the mold surface side. The conventional forming method of the J-shaped wall solves the problem of pores or stratification in the non-destructive detection of the R corner area of ​​the product. The base plate tooling has poor thermal deformation and uneven pressure in the base plate area. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional diagram of the combination of the bottom plate tooling and the main body tooling;

[0028] Figure 2 It is a schematic diagram of the combination of the bottom plate tooling and the main body tooling;

[0029] Figure 3 This is a schematic diagram of the C-type cover plate positioning ears;

[0030] In the figure: 1. forming mold, 2. bottom plate, 3. C-shaped cover plate, 4. positioning ear, 5. positioning screw sleeve. DETAILED DESCRIPTION

[0031] The present application will be described in detail below in conjunction with the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the structure and technical common knowledge is omitted to avoid unnecessary confusion of the concept of the present application.

[0032] Embodiment 1: In conjunction with the accompanying drawings, the present application discloses a process for solving R corner defects of a carbon fiber composite material wall, which is characterized by comprising the following steps:

[0033] Step 1: Making a composite base plate;

[0034] First, QY260 / EW100 high temperature curing material, i.e. glass cloth prepreg with bismaleimide resin matrix is ​​used to replace Q235 ordinary carbon structural steel material used in the prior art to produce composite base plate, and the size of the composite base plate is consistent with the size of the existing base plate tooling; then, the edge of the composite base plate is cut to retain the required size of the wall;

[0035] Step 2: Make a C-shaped cover;

[0036] First, make a C-type cover plate forming mold: the C-type cover plate forming mold is made of prepreg consistent with the product, and the inner surface of the C-type cover plate forming mold is consistent with the C-type area of ​​the wall. The inner surface of the C-type area of ​​the wall is extracted as the outer surface of the C-type mold. The inner surface of the C-type cover plate forming mold is consistent with the inner surface of the C-type area of ​​the wall. The C-type cover plate forming mold is processed by a metal mold; secondly, lay layers on the C-type cover plate forming mold, lay auxiliary materials for curing; cut according to the cover plate cutting line to retain the effective area; thirdly, paste the C-type cover plate 3: lay a layer of adhesive demoulding cloth on the surface of the C-type cover plate forming mold, and the adhesive side is bonded to the C-type cover plate forming mold; lay 2 layers of unvulcanized silicone rubber and 2 layers of carbon fiber fabric consistent with the product material, as well as 2 layers of unvulcanized silicone rubber in the C-type cover plate forming mold; then, lay the auxiliary materials into the tank for curing to form a C-type cover plate; then, demold and cut the C-type cover plate 3 so that the size of the C-type cover plate 3 is consistent with the size of the wall;

[0037] Step 3: Produce wall;

[0038] First, the mold is cleaned, and 8 layers of Z-shaped prepreg are laid on the molding mold 1 to form the main tooling;

[0039] Then, 8 layers of straight prepreg are laid on the bottom plate 2 to form a bottom plate tooling, and the bottom plate tooling is supported at the back; after the bottom plate tooling is combined with the main body tooling, 8 layers of C-type prepreg are laid on the wall;

[0040] After that, after the plying is completed, the peeling cloth and the isolation film are laid on the wall surface, and then the C-type cover plate 3 is placed; after the gas-conducting medium is laid on the C-type cover plate 3, the vacuum bag is pasted and put into the tank for curing.

[0041] Finally, it is taken out of the oven, demolded and tested.

[0042] Furthermore, a positioning ear 4 is provided at the wider end of the C-shaped cover plate 3 , and a positioning hole is pre-set on the positioning ear 4 ; a positioning screw sleeve 5 is provided at a position corresponding to the positioning hole on the molding die 1 of the main tooling to fasten the positioning hole on the positioning ear 4 .

[0043] Furthermore, the positioning holes are pre-set on the positioning ears 4, and the positioning holes are first opened. Initial hole, then expanded to Positioning holes.

[0044] Furthermore, the positioning screw sleeve 5 is changed into a positioning pin for fastening the positioning hole on the positioning ear 4 .

[0045] Furthermore, in the production of the composite base plate, 50 layers of QY260 / EW100 high temperature curing material, i.e. glass cloth with a bismaleimide resin matrix, are laid on the base plate tooling; the thickness of a single layer of QY260 / EW100 high temperature curing material after curing is 0.09 mm, and the thickness of the composite base plate after curing is 4.5 mm, which meets the wall requirements.

[0046] Furthermore, the material of the bottom plate 2 is consistent with the material of the wall.

[0047] Furthermore, in the production of the composite base plate, 25 layers of base plate 2 material consistent with the wall material, namely carbon cloth, are laid on the base plate tooling. The single layer thickness of the carbon cloth is 0.125 mm, and the thickness of the 25 carbon cloth base plate after curing is 3.2 mm, which meets the wall requirements.

[0048] Furthermore, the thickness of the C-shaped cover plate forming die is 5 mm.

[0049] Furthermore, the C-shaped cover plate forming mold is a concave mold, the inner surface of which is consistent with the inner surface profile of the C-shaped area of ​​the wall, and the size exceeds the single side of the wall by 30-50 mm.

[0050] Working principle and process:

[0051] 1. After the base plate is replaced with the same material as the wall, during the curing process, the base plate has the same thermal expansion coefficient as the wall material, which can effectively ensure the contact position between the base plate area and the wall;

[0052] 2. The use of C-shaped cover plate can keep the pressure of C-shaped area of ​​the wall consistent during the curing process, and the void ratio of the formed wall can be controlled below 1.5%, avoiding the product void problem caused by vacuum bag bridging or uneven pressure in the R corner area;

[0053] 3. Adding a positioning device can effectively ensure the axial positioning of the C-type cover, avoid the cover's axial positioning error causing it to not fit the product, and the pressure cannot be effectively transmitted, while also improving the work efficiency of placing the C-type cover;

[0054] 4. Compared with metal tooling, the use of composite tooling improves product quality, reduces the weight of tooling, and is beneficial to production transportation; at the same time, composite tooling has good corrosion resistance and high reuse rate; compared with metal tooling, which needs to be polished and coated with release agent after each use, composite tooling only needs to be pasted with adhesive release cloth to realize production, which improves the efficiency of mold preparation and reduces production costs.

[0055] The above embodiments are merely illustrative of the principles and effects of the present application, and are not intended to limit the present application. Anything within the technical concept disclosed in the present application, and any simple replacement or change based on the technical solution of the present application, shall fall within the protection scope of the present application.

Claims

1. A process for solving R corner defects of carbon fiber composite wall, characterized in that: The following steps are involved: Step 1: Making a composite base plate; First, QY260 / EW100 high temperature curing material, i.e. glass cloth prepreg with bismaleimide resin matrix, is used to replace Q235 ordinary carbon structural steel material used in the prior art to produce a composite base plate, the size of which is consistent with the size of the existing base plate tooling; then, the edge of the composite base plate is cut to retain the required size of the wall; Step 2: Make a C-shaped cover; First, make a C-type cover plate forming mold: the C-type cover plate forming mold is made of prepreg consistent with the product, and the inner surface of the C-type cover plate forming mold is consistent with the C-type area of ​​the wall; the inner surface of the C-type area of ​​the wall is extracted as the outer surface of the C-type mold, and the inner surface of the C-type cover plate forming mold is consistent with the inner surface of the C-type area of ​​the wall. The C-type cover plate forming mold is processed by a metal mold; secondly, lay layers on the C-type cover plate forming mold, lay auxiliary materials for curing; cut according to the cover plate cutting line Cut to retain the effective area; next, paste the C-type cover plate (3): lay a layer of adhesive demoulding cloth on the surface of the C-type cover plate forming mold, and bond the adhesive side to the C-type cover plate forming mold; lay 2 layers of unvulcanized silicone rubber and 2 layers of carbon fiber fabric consistent with the product material, and 2 layers of unvulcanized silicone rubber in the C-type cover plate forming mold; then, lay the auxiliary material into the tank for curing to form the C-type cover plate; then, demould and cut the C-type cover plate (3) so that the size of the C-type cover plate (3) is consistent with the size of the wall; The thickness of the C-shaped cover plate forming die is 5 mm; The inner surface of the C-shaped cover plate forming mold is a concave mold, which is consistent with the inner surface profile of the C-shaped area of ​​the wall, and the size exceeds the single side of the wall by 30-50mm; Step 3: Produce wall; First, the mold is cleaned, and 8 layers of Z-shaped prepreg are laid on the molding mold (1) to form the main tooling; Then, 8 layers of straight prepreg are laid on the bottom plate (2) to form a bottom plate tooling, and the bottom plate tooling is used as support at the back; after the bottom plate tooling is combined with the main body tooling, 8 layers of C-type prepreg are laid on the wall; After the plying is completed, a peeling cloth and an isolation film are laid on the wall surface, and then a C-shaped cover plate (3) is placed; after the gas-conducting medium is laid on the C-shaped cover plate (3), a vacuum bag is pasted and put into a tank for curing; Finally, it is taken out of the oven, demolded and tested.

2. The process for solving R corner defects of carbon fiber composite wall according to claim 1, characterized in that: A positioning ear (4) is provided at the wider end of the C-shaped cover plate (3), and a positioning hole is pre-set on the positioning ear (4); a positioning screw sleeve (5) is added to the molding die (1) of the main tooling at a position corresponding to the positioning hole, so as to fasten the positioning hole on the positioning ear (4).

3. The process for solving R corner defects of carbon fiber composite wall according to claim 2, characterized in that: The positioning hole is pre-set on the positioning ear (4), firstly a Ø2.1 mm initial hole is made, and then expanded to a Ø5 mm positioning hole.

4. The process for solving R corner defects of carbon fiber composite wall according to claim 2, characterized in that: The positioning screw sleeve (5) is replaced by a positioning pin, which is used to fasten the positioning hole on the positioning ear (4).

5. The process for solving R corner defects of carbon fiber composite material wall according to claim 1, characterized in that: The composite base plate is made by laying 50 layers of QY260 / EW100 high temperature curing material, i.e. glass cloth with bismaleimide resin matrix, on the base plate tooling; the thickness of a single layer of QY260 / EW100 high temperature curing material after curing is 0.09 mm, and the thickness of the composite base plate after curing is 4.5 mm, which meets the wall requirements.

6. The process for solving R corner defects of carbon fiber composite wall according to claim 1, characterized in that: The material of the bottom plate (2) is consistent with the material of the wall.

7. The process for solving R corner defects of carbon fiber composite wall according to claim 6, characterized in that: In the manufacturing of the composite base plate, 25 layers of base plate (2) material consistent with the wall material, namely carbon cloth, are laid on the base plate tooling. The thickness of a single layer of carbon cloth is 0.125 mm. The thickness of the 25 carbon cloth base plate after curing is 3.2 mm, which meets the wall thickness requirement.

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