A core assembly and a longeron-stiffened wall panel

Abstract

The application relates to the technical field of long string reinforced wallboard preparation, in particular to a core mold assembly and a long string reinforced wallboard. The core mold assembly comprises an inner core mold unit and a flexible rubber core mold, the inner core mold unit comprises an inner core mold and a first non-porous isolation film, a first strippable cloth, a tubular vacuum bag, a second strippable cloth and a second non-porous isolation film which are sequentially coated on the outer surface of the inner core mold; the flexible rubber core mold comprises a rubber inner cavity, and the inner core mold unit is arranged in the rubber inner cavity. The inner core mold and the flexible rubber core mold are assembled into the core mold assembly, the rubber core mold of the large-size long string part can be demolded, the core mold deformation in the fiber laying process can be prevented, the assembly of the flexible rubber core mold can meet the multiple use of the core mold, and the manufacturing and material costs are effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of long string reinforced wallboard preparation, in particular to a core mold assembly and long string reinforced wallboard. BACKGROUND

[0002] Carbon fiber reinforced composite material has its higher specific modulus and specific strength, corrosion resistance, high temperature resistance, fatigue resistance, good damping shock resistance, strong designability and good dimensional stability, and other advantages, and carbon fiber reinforced composite material is widely used in aviation, aerospace and other fields. The application of composite materials in civil aviation field gradually increases, and the weight percentage increases from 4.5% of A300 to 53% of A350, and from 10% of B777 to 50% of B787. The hat-shaped long string reinforced wallboard is widely used in the mechanism design of the hat-shaped long string reinforced wallboard due to the good torsion resistance and bending resistance. The carbon fiber reinforced M21 epoxy resin unidirectional tape prepreg of HEXCEL can be used as the body material of the long string and the skin. In addition, there can be multiple long strings on the skin, and the skin is generally wider and longer than the long string, and is used for assembly with other parts, so that the edge of the long string in the length direction has the skin.

[0003] In the development process of the hat-shaped long string reinforced wallboard, the end of the long string is encountered. The quality of the inner surface of the skin is poor, there are fiber wrinkles, unqualified thickness and other problems. For the hat-shaped long string reinforced wallboard structure composite material part formed by the negative mold, a solid rubber core mold is generally used, but this scheme is not suitable for the hat-shaped long string reinforced wallboard with large size, because the solid rubber core mold has the problems of difficult demolding after curing, and easy to cause fiber splitting, delamination and other defects at the end of the long string, and the core mold is easy to be damaged in the demolding process. SUMMARY

[0004] In view of the above-mentioned defects of the prior art, the purpose of the present application is to provide a core mold assembly and long string reinforced wallboard for solving the problems in the prior art.

[0005] To achieve the above-mentioned purpose and other related purposes, one aspect of the present application provides a core mold assembly, which comprises an inner core mold unit and a flexible rubber core mold, the inner core mold unit comprises an inner core mold and a first non-porous isolation film, a first strippable cloth, a tubular vacuum bag, a second strippable cloth and a second non-porous isolation film which are successively coated on the outer surface of the inner core mold; the flexible rubber core mold comprises a rubber inner cavity, and the inner core mold unit is arranged in the rubber inner cavity.

[0006] In some embodiments of the present application, the inner core mold comprises a metal piece, and the outer surface of the metal piece is coated with rubber; preferably, the metal piece is a metal chain.

[0007] In some embodiments of the present application, the thickness of the first non-porous isolation film is 15um-50um.

[0008] In some embodiments of the present application, the first peelable cloth has a thickness of 0.1mm-0.4mm.

[0009] In some embodiments of the present application, the tubular vacuum bag has a width of 101mm and a thickness of 50um-75um.

[0010] In some embodiments of the present application, the second peelable cloth has a thickness of 0.1mm-0.4mm.

[0011] In some embodiments of the present application, the second non-porous release film has a thickness of 15um-50um.

[0012] Another aspect of the present application provides a method for preparing a core assembly, comprising the following steps:

[0013] S1 wrapping a first non-porous release film on the outer surface of the inner core mold;

[0014] S2 wrapping a first peelable cloth on the outer surface of the first non-porous release film;

[0015] S3 placing the inner core mold wrapped with the first peelable cloth into a tubular vacuum bag, wrapping a second peelable cloth on the outer surface of the tubular vacuum bag, and wrapping a second non-porous release film on the outer surface of the second peelable cloth to obtain an inner core mold unit;

[0016] S4 placing the inner core mold unit into the rubber inner cavity of the flexible rubber core mold to obtain a core assembly.

[0017] In some embodiments of the present application, the method for preparing the inner core mold comprises:

[0018] a. brushing a release agent in the inner cavity of the inner core mold injection molding tooling;

[0019] b. after the release agent is dried, placing a metal piece in the inner core mold injection molding tooling and fixing the metal piece;

[0020] c. pouring liquid rubber into the inner cavity of the inner core mold injection molding tooling;

[0021] d. standing for curing at room temperature, and after the curing is completed, disassembling the inner core mold injection molding tooling and demolding the cured inner core mold.

[0022] In some embodiments of the present application, in step b, the metal piece is a metal chain.

[0023] In some embodiments of the present application, in step d, the curing time is at least 24h.

[0024] Another aspect of the present application provides the use of the core assembly described in the present application in the preparation of a longeron stiffened panel.

[0025] Another aspect of the present application provides a manufacturing method of a long string reinforced wallboard, comprising the following steps:

[0026] 1) Turn the net size long string into the negative mold forming tool; the net size long string comprises a long string cap top, two symmetrically distributed long string cap waists and two symmetrically distributed long string edge strips;

[0027] 2) Place the core mold assembly of the present application into the inner cavity of the net size long string;

[0028] 3) Fill the remaining gap in the inner cavity of the long string with twist strips using laser projection positioning, set a temporary vacuum bag on the outer surface of the long string and compact it, and after assembly, the cap bottom of the rubber core mold, the twist strips, the long string edge strips and the skin laying area of the negative mold forming tool are flush;

[0029] 4) The end of the net size long string is provided with a first cover plate; the negative mold forming tool is provided with a cover plate groove matched with the first cover plate; the first cover plate is arranged in the cover plate groove;

[0030] 5) Lay the skin on the skin laying area of the negative mold forming tool, the long string edge strip area and the cap bottom area of the flexible rubber core mold, and form a skin after laying the skin, and then take out the inner core mold, the first non-porous isolation film and the first peelable cloth;

[0031] 6) Fix a second cover plate on the outer surface of the long string skin, the second cover plate is provided with a pneumatic outer surface vacuum bag, the pneumatic outer surface vacuum bag is sealed with the second cover plate through a sealing rubber strip, and a tubular vacuum bag is connected with the pneumatic outer surface vacuum bag;

[0032] 7) Demold after curing.

[0033] In some embodiments of the present application, the long string is laid and cut to obtain the net size long string in step 1).

[0034] In some embodiments of the present application, the long string cap top and the two long string cap waists form a long string inner cavity; the negative mold forming tool comprises a negative mold tool cap top area, two negative mold tool cap waist areas and two negative mold tool edge strip areas, and the negative mold tool cap top area and the two negative mold tool cap waist areas form a long string accommodating cavity; wherein the long string cap top is aligned with the negative mold tool cap top area, the long string cap waist is aligned with the negative mold tool cap waist area, and the long string edge strip is aligned with the negative mold tool edge strip area.

[0035] In some embodiments of the present application, the demolding after curing step includes: removing the first auxiliary material, demolding the first cover plate and the second cover plate respectively, taking out the second auxiliary material in the inner cavity of the flexible rubber core mold, vacuum sealing the two ends of the flexible rubber core mold, deforming the flexible rubber core mold by vacuumizing, and then manually pulling out the flexible rubber core mold from the inner cavity of the longeron, and taking out the third auxiliary material after the flexible rubber core mold is pulled out.

[0036] In some embodiments of the present application, the vacuum sealing of the two ends of the flexible rubber core mold includes sealing one end of the flexible rubber core mold with a second sealing rubber strip and a vacuum bag, and sealing the other end of the flexible rubber core mold with a third sealing rubber strip, a vacuum bag and a breathable sealing bag, and the inside is provided with a vacuum nozzle base.

[0037] In some embodiments of the present application, the flexible rubber core mold is deformed to 40% to 50% of the original size by vacuumizing.

[0038] In some embodiments of the present application, the first auxiliary material includes a pneumatic outer shape surface vacuum bag and a first sealing rubber strip.

[0039] In some embodiments of the present application, the second auxiliary material includes a tubular vacuum bag, a second peelable cloth and a second non-porous isolation film.

[0040] In some embodiments of the present application, the third auxiliary material includes a second sealing rubber strip, a third sealing rubber strip, a vacuum bag and a vacuum bag breathable sealing bag.

[0041] Compared with the prior art, the core mold assembly of the present application has the following beneficial effects:

[0042] The core mold assembly of the present application is assembled by the inner core mold and the flexible rubber core mold, which can ensure the supportability of the rubber core mold during the hat-shaped longeron stiffened wall panel skin laying process, and can ensure that the inner core mold is smoothly pulled out after the laying is completed without damaging the flexible rubber core mold and the un-solidified longeron and skin, and the flexible rubber core mold can be smoothly pulled out after solidification without damaging the flexible rubber core mold and the solidified longeron and skin. The work efficiency is improved, and the core mold and longeron parts are also protected, reducing the loss and the number of unqualified products.

[0043] The assembly of the inner core mold and the flexible rubber core mold can ensure the demolding of the flexible rubber core mold of large-size parts, and can prevent the deformation of the core mold during the laying process. The assembly of the flexible rubber core mold can meet the multiple use of the core mold, effectively reducing the manufacturing and material costs. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a sectional view of the core mold assembly provided by the present application.

[0045] Figure 2is a schematic diagram of the inner core mold injection forming tool provided by the present application.

[0046] Figure 3 is a cross-sectional view of the stringer-stiffened wall panel provided by the present application.

[0047] Figure 4 is a schematic diagram of the stringer-stiffened wall panel forming tool provided by the present application.

[0048] Figure 5 is a schematic diagram of the hat-shaped stringer end cap and tool provided by the present application.

[0049] Figure 6 is a schematic diagram of the final bag sealing.

[0050] Figure 7 is an external appearance diagram of the stringer forming piece prepared by the present application.

[0051] Figure 8 is an external appearance diagram of the flexible rubber core mold after the assembly method of the rubber core mold of the present application is used and demolding.

[0052] Figure 9 is a physical diagram of the vacuum nozzle base used by the present application.

[0053] Figure 10 is a physical diagram of one side of the flexible rubber core mold 17 sealed by the second sealing strip and the vacuum bag used by the present application.

[0054] Figure 11 is a physical diagram of the flexible rubber core mold 17 being pulled out of the stringer inner cavity by artificial dragging.

[0055] Figure 12 is a physical diagram of the inner core mold after the inner core mold is pulled out in Example 2.

[0056] Figure 13 is a physical diagram of the assembled inner core mold unit in Example 1.

[0057] Figure 14 is an appearance quality diagram of the wall panel prepared in Example 2. Wherein 14a is the stringer face of the wall panel, and 14b is the skin face of the wall panel.

[0058] Figure 15 is a wall panel thickness point diagram prepared in Example 2.

[0059] Figure 16 is a metallographic sample of the wall panel prepared in Example 2.

[0060] Figure 17 is an electron microscope image of the wall panel prepared in Example 2.

[0061] Figure 18is the ultrasonic testing result of the wallboard prepared in Example 2.

[0062] Figure 19 is a structural schematic diagram of the first cover plate. BRIEF DESCRIPTION OF DRAWINGS

[0064] 1 core assembly

[0065] 11 inner core mold

[0066] 111 metal chain

[0067] 12 first non-porous release film

[0068] 13 first peelable cloth

[0069] 14 tubular vacuum bag

[0070] 15 second peelable cloth

[0071] 16 second non-porous release film

[0072] 17 flexible rubber core mold

[0073] 2 inner core mold injection molding tooling

[0074] 21 inner core mold injection molding tooling inner cavity

[0075] 3 stringer

[0076] 31 stringer cap top

[0077] 32 stringer cap waist

[0078] 33 stringer bead

[0079] 4 negative mold tooling

[0080] 41 negative mold tooling cap top area

[0081] 42 negative mold tooling cap waist area

[0082] 43 negative mold tooling bead area

[0083] 44 negative mold tooling stringer cap top R angle area

[0084] 45 skin layup area

[0085] 46 cover plate groove

[0086] 47 tooling stringer outer rubber core mold groove

[0087] 5 first cover plate

[0088] 51 rubber core mold bonding portion

[0089] 511 First bonding section

[0090] 512 Second bonding section

[0091] 52 Retention part

[0092] 53 Cover plate R area

[0093] 54 Fixing Holes

[0094] 6 Second cover plate

[0095] 7. Long stringer skin

[0096] 8 twisted strips

[0097] 9. Pneumatically designed vacuum bags

[0098] 10 First sealing strip Detailed Implementation

[0099] In the description of this invention, it should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the implementation conditions of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are merely for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0100] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0101] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0102] The core mold assembly 1 can be regarded as an assembly after the inner core mold 11 and the flexible rubber core mold 17 are assembled. In the existing assembly of the inner core mold 11 and the flexible rubber core mold 17, the inner core mold 11 is mainly used for supporting during the fiber laying process, but the flexible rubber core mold 17 is low in hardness, and is severely deformed during the fiber laying process, so that the automatic fiber laying machine exceeds the maximum range. Therefore, in order to improve the supportability of the flexible rubber core mold 17 during the fiber laying process, an inner core mold 11 is usually assembled in the inner cavity of the flexible rubber core mold 17 to improve the supportability of the flexible rubber mold. However, since the long stringer 3 has a long size and the core mold is made of rubber, the resistance is large during the process of inserting the inner core mold 11 into the inner cavity of the flexible rubber core mold and the process of removing the inner core mold 11 from the inner cavity of the flexible rubber core mold 17, and the flexible rubber core mold 17 is easily damaged.

[0103] The present application unexpectedly finds a core mold assembly through a large number of tests, which can ensure that the supportability of the rubber core mold is good during the fiber laying process of the hat-shaped long stringer stiffened wall plate skin, and can ensure that the inner core mold 11 is smoothly removed after the fiber laying is completed, without damaging the flexible rubber core mold 17, the uncured long stringer 3 and the long stringer skin 7, and after curing, the flexible rubber core mold 17 can be smoothly removed without damaging the flexible rubber core mold 17, the cured long stringer 3 and the long stringer skin 7. The work efficiency is improved, and the core mold and the long stringer 3 parts are also protected, thereby reducing the loss and the number of unqualified products. Through the assembly of the inner core mold 11 and the flexible rubber core mold 17, the demolding of the rubber core mold of the large-size part can be ensured, and the use of the core mold can be ensured through the assembly of the rubber core mold, thereby effectively reducing the manufacturing and material costs. On this basis, the present application is completed.

[0104] The core mold assembly provided by the present application comprises an inner core mold unit and a flexible rubber core mold 17. Figure 1 The core mold assembly provided by the present application comprises an inner core mold unit and a flexible rubber core mold 17.

[0105] The core mold assembly provided by the present application comprises an inner core mold unit and a flexible rubber core mold 17. Figure 2The inner core mold 11 comprises a metal piece, and an outer surface of the metal piece is coated with rubber. The metal piece can be a metal chain 111, for example. The main role of the inner core mold 11 is to support the flexible rubber core mold 17 during the laying process. The main manufacturing method of the inner core mold 11 is to pour liquid rubber mixed according to the proportioning requirements into the inner cavity of a forming tool, and to add a metal piece in the liquid rubber to enhance the rigidity of the inner core mold 11. After the pouring of the liquid rubber is completed, the liquid rubber is cured at room temperature, and the inner core mold 11 is obtained after demolding.

[0106] In the core mold assembly provided by the application, referring to Figure 1 The first non-porous isolation film 12 is arranged on the outer surface of the inner core mold 11, and the purpose is to make the surface of the inner core mold 11 smooth. In general, the first non-porous isolation film 12 only needs to meet an appropriate thickness. The thickness of the first non-porous isolation film 12 can be 15 um to 50 um, 15 um to 25 um, 25 um to 35 um, or 35 um to 50 um, for example. The first non-porous isolation film 12 can be an A4000 non-porous isolation film of Airtech, for example.

[0107] In the core mold assembly provided by the application, the first strippable cloth 13 is coated on the outer surface of the first non-porous isolation film 12, and the purpose of arranging the first strippable cloth 13 is to assist in demolding the inner core mold 11. In general, the first strippable cloth 13 only needs to meet an appropriate thickness. The thickness of the first strippable cloth 13 can be 0.1 mm to 0.4 mm, 0.1 mm to 0.2 mm, 0.2 mm to 0.3 mm, or 0.3 mm to 0.4 mm, for example. The first strippable cloth 13 can be a Release Ply F of Airtech, for example.

[0108] In the core mold assembly provided by the application, referring to Figure 1 The tubular vacuum bag 14 is coated on the outer surface of the first strippable cloth 13, and the purpose is to keep the pressure inside the flexible rubber core mold consistent with the pressure of the external autoclave. In general, the inner core film can be placed in the tubular vacuum bag 14 together with the first non-porous isolation film 12 and the first strippable cloth 13 after the coating. The tubular vacuum bag 14 needs to meet a certain volume. For example, the width of the tubular vacuum bag 14 is 101 mm. The thickness of the tubular vacuum bag 14 can be 50 um to 75 um, 50 um to 65 um, or 65 um to 75 um, for example.

[0109] In the core mold assembly provided by the application, referring to Figure 1A second peel ply 15 is wrapped on the outer surface of the vacuum bag. The second peel ply 15 is arranged to guide the gas between the flexible rubber core mold and the tubular vacuum bag out. In general, the second peel ply 15 can meet the appropriate thickness. The thickness of the second peel ply 15 can be, for example, 0.1mm-0.4mm, 0.1mm-0.2mm, 0.2mm-0.3mm, or 0.3mm-0.4mm, etc. The second peel ply 15 can be, for example, ReleasePly F of Airtech.

[0110] In the core mold assembly provided by the present application, referring to Figure 1 A second non-porous release film 16 is wrapped on the outer surface of the second peel ply 15. The second non-porous release film 16 is arranged to prevent the flexible rubber core mold from sticking to the peel ply during the curing process, so that the peel ply and other auxiliary materials inside the flexible rubber core mold cannot be removed. In general, the second non-porous release film 16 can meet the appropriate thickness. The thickness of the second non-porous release film 16 can be, for example, 15um-50um, 15um-25um, 25um-35um, or 35um-50um, etc. The second non-porous release film 16 can be, for example, A4000 non-porous release film of Airtech.

[0111] The present application also provides a preparation method of a core mold assembly, which comprises the following steps:

[0112] S1 wrapping a first non-porous release film 12 on the outer surface of the inner core mold 11;

[0113] S2 wrapping a first peel ply 13 on the outer surface of the first non-porous release film 12;

[0114] S3 placing the inner core mold 11 wrapped with the first peel ply 13 into a tubular vacuum bag 14, wrapping a second peel ply 15 on the outer surface of the tubular vacuum bag 14, wrapping a second non-porous release film 16 on the outer surface of the second peel ply 15 to obtain an inner core mold unit;

[0115] S4 placing the inner core mold unit into the rubber inner cavity of the flexible rubber core mold 17 to obtain the core mold assembly 1.

[0116] In the preparation method of the core mold assembly provided by the present application, step S1 is wrapping a first non-porous release film 12 on the outer surface of the inner core mold 11. In this regard, Figure 2 The preparation method of the inner core mold 11 comprises:

[0117] a. first brushing a release agent in the inner cavity of the inner core mold injection molding tool 2.

[0118] b. after the release agent is dried, placing a metal part in the inner core mold injection molding tool 2 and fixing the metal part.

[0119] c. pouring liquid rubber into the inner cavity of the inner core mold injection molding tooling 2.

[0120] d. curing at room temperature, and after the curing is completed, disassembling the inner core mold injection molding tooling 2, and demolding the cured inner core mold 11.

[0121] In step a of the present application, the inner core mold injection molding tooling 2 can be an existing molding tooling for preparing the inner core mold 11.

[0122] In step b of the present application, after the demolding agent is dried, a metal piece is placed in the inner core mold injection molding tooling 2, which can be a metal chain 111 for example. After the metal chain 111 is straightened and fixed, the inner core mold injection molding tooling 2 is assembled.

[0123] In step c of the present application, liquid rubber is poured into the inner cavity of the inner core mold injection molding tooling 2. The liquid rubber is a viscous liquid at room temperature with a relative molecular mass of about 2000-10000, which can form a three-dimensional network structure through appropriate chemical reactions, thereby obtaining an oligomer with similar physical and mechanical properties to ordinary vulcanized rubber. The liquid rubber of the present application can be purchased from existing commercial products.

[0124] In step d of the present application, the curing time at room temperature is at least 24h for example. After the inner core mold injection molding tooling 2 is disassembled, the inner core mold 11 is demolded to obtain the inner core mold 11.

[0125] The present application also provides the use of the core mold assembly of the first aspect of the present application in the preparation of a stringer-stiffened panel.

[0126] The present application also provides a method for manufacturing a stringer-stiffened panel, comprising the following steps:

[0127] 1) turning a net-size stringer 3 into a negative mold tooling 4; the net-size stringer 3 comprises a stringer cap top 31, two symmetrically distributed stringer cap waists 32, and two symmetrically distributed stringer edge strips 33;

[0128] 2) placing the core mold assembly 1 of the first aspect of the present application into the inner cavity of the net-size stringer 3;

[0129] 3) using laser projection positioning to fill the remaining gaps in the stringer inner cavity with the twist strip 8, and to set and compact the rubber core mold on the outer surface of the stringer 3, so that the cap bottom of the rubber core mold, the twist strip 8, the stringer edge strip 33, and the skin laying area of the negative mold tooling 4 are flush after assembly.

[0130] 4) the end of the net size stringer 3 is provided with a first cover plate 5; the female mold forming tool 4 is provided with a cover plate groove 46 matched with the first cover plate 5; the first cover plate 5 is arranged in the cover plate groove 46;

[0131] 5) The skin is laid on the skin laying area 45 of the female mold forming tool 4, the stringer edge strip 33 area, and the cap bottom area of the flexible rubber core mold 17. After the laying is completed, the skin is formed, and the inner core mold 11, the first non-porous isolation film 12 and the first peelable cloth 13 are taken out;

[0132] 6) The second cover plate 6 is fixed on the outer surface of the stringer skin, the second cover plate 6 is provided with a pneumatic outer shape vacuum bag 9, the pneumatic outer shape vacuum bag 9 is sealed with the second cover plate 6 through the first sealing rubber strip 10, and the tubular vacuum bag 14 is communicated with the pneumatic outer shape vacuum bag 9;

[0133] 7) After curing, demolding.

[0134] In the manufacturing method of the stringer stiffened wallboard provided by the application, step 1) is to turn the net size stringer 3 into the female mold forming tool 4. The structure of the stringer is shown in Figure 3 , wherein the net size stringer 3 is obtained after laying and cutting the stringer 3. Specifically, the preparation of the net size stringer 3 is completed by manual laying of the stringer and ultrasonic automatic cutting. Further, the net size stringer 3 includes a stringer cap top 31, two symmetrically distributed stringer cap waists 32 and two symmetrically distributed stringer edge strips 33. Two stringer cap waists 32 are respectively connected with two side edges of the stringer cap top 31. The stringer edge strip 33 is connected with the stringer cap waist 32, so as to form the stringer 3 with a cap-shaped cross section. Specifically, the stringer cap top 31 and the two stringer cap waists 32 enclose a stringer inner cavity. The structure of the female mold forming tool 4 is shown in Figure 4 . The female mold forming tool 4 includes a female mold tool cap top area 41, two female mold tool cap waist areas 42 and two female mold tool edge strip areas 43, and the female mold tool cap top area 41 and the two female mold tool cap waist areas 42 form a stringer containing cavity. It also includes a forming tool stringer outer rubber core mold groove 47. Wherein, the stringer cap top 31 is aligned with the female mold tool cap top area 41, the stringer cap waist 32 is aligned with the female mold tool cap waist area 42, and the stringer edge strip 33 is aligned with the female mold tool edge strip area 43, which can ensure the accurate assembly position of the stringer 3.

[0135] In the manufacturing method of the stringer stiffened wallboard provided by the application, step 2) is to place the core mold assembly 1 prepared by the core mold assembly 1 preparation method of the application into the stringer inner cavity. Wherein, the core mold assembly 1 can be prepared by the core mold assembly 1 preparation method of the application. During the placement process, the assembled core mold assembly 1 can be placed into the stringer inner cavity by using the groove positioning.

[0136] The manufacturing method of the long string reinforced wallboard provided by the application, step 3) is to fill the remaining gap in the long string cavity with the twist strip 8, seal the temporary vacuum bag, press the long string 3 and compact it, and ensure that the flexible rubber core mold 17 and the long string cavity are perfectly matched. After assembly, the bottom of the rubber core mold cap, the twist strip 8, the long string edge strip 33, and the skin laying area of the negative mold forming tool 4 are flush.

[0137] The manufacturing method of the long string reinforced wallboard provided by the application, step 4) is that the end of the long string 3 with the net size is provided with a first cover plate 5. The first cover plate 5 is a hard cover plate, which can be a metal cover plate, for example. The material of the metal cover plate should be selected considering the material close to the thermal expansion coefficient of the long string reinforced wallboard. For example, it can be a steel cover plate, and more for example, it can be an Invar steel material. The negative mold forming tool 4 is provided with a cover plate groove 46 matched with the first cover plate 5; the first cover plate 5 is arranged in the cover plate groove 46, see Figure 4 .

[0138] The manufacturing method of the long string reinforced wallboard provided by the application, step 5) is to lay the skin on the skin laying area 45 of the negative mold forming tool 4, the long string edge strip 33 area, and the cap bottom area of the flexible rubber core mold 17. After the laying is completed, the skin is formed, and the inner core mold 11, the second peelable cloth 15 and the second non-porous isolation film 16 are taken out. The skin laying can be performed on an automatic fiber laying machine, for example. The laying angle is according to the angle specified in the drawing, which can be [-45° / 45° / 45° / 90° / -45° / 0° / -45° / 90° / 45° / 45° / -45°], for example. The laying gap should meet the design drawing requirements. The laying gap can be ≤1mm, for example.

[0139] The manufacturing method of the long string reinforced wallboard provided by the application, see Figure 6 , step 6) is to fix the second cover plate 6 on the outer surface of the long string skin 7. The fixing method can be pin positioning assembly, for example. The pneumatic outer surface vacuum bag 9 is sealed with the second cover plate 6 through the first sealing strip 10, specifically, the first sealing strip 10 is pasted in the tool sealing bag area. The second cover plate 6 is provided with the pneumatic outer surface vacuum bag 9, and the tubular vacuum bag 14 is communicated with the pneumatic outer surface vacuum bag 9. The curing pressure in the rubber core mold cavity and outside the outer vacuum bag is ensured to be the same during the curing process.

[0140] Further, the second cover plate 6 is a pneumatic outer surface hard cover plate. The pneumatic outer surface hard cover plate can be prepared by the following method:

[0141] 1. The cover plate forming tool is brushed with a release agent, and after the release agent is completely dried, a layer of tool fabric prepreg with a resin content of 45% is laid on the surface of the tool, the laying angle is 0°, the nominal thickness of the tool prepreg fabric is 0.23mm, after the laying of this layer of prepreg is completed, a temporary vacuum bag is sealed for pre-compaction, the compaction time is not less than 15min, and the compaction vacuum degree is lower than-80KPa;

[0142] 2. The second and third layers are laid with tool fabric prepreg with a resin content of 38%, the laying angle is 45°, the nominal thickness of the tool prepreg fabric is 0.65mm, attention should be paid to air guiding during the laying process, and each layer needs to be pre-compacted once after being laid, the compaction time is not less than 15min, and the compaction vacuum degree is lower than-80KPa;

[0143] 3. The fourth layer is laid with tool fabric prepreg with a resin content of 45%, the laying angle is 0°, the nominal thickness of the tool prepreg fabric is 0.23mm, after the laying of the fourth layer is completed, a temporary vacuum bag is sealed for pre-compaction, the compaction time is not less than 15min, and the compaction vacuum degree is lower than-80KPa;

[0144] 4. The final vacuum bag is sealed, attention should be paid to air guiding during the sealing process, air guiding filaments are placed in the remaining area of the part, the air guiding filaments contact the edge air guiding fibers, the surface can be selected with a porous release film or a non-porous release film, the selection of the release film is determined according to the actual product size and shape, and it is recommended to use a porous release film for large-sized parts.

[0145] 5. Curing, this cover plate curing is a two-step curing process, which includes pre-curing and post-curing processes, the pre-curing pressure is 0.6Mpa, the whole process is vacuumized during the curing process, the temperature is raised to 60℃ at a rate of 0.5℃ / min, and the temperature is kept for 16 hours.

[0146] 6. After the pre-curing is completed, the bag is removed, and the positioning holes are drilled using a drill jig, and the part is demolded after the drilling is completed.

[0147] 7. The cover plate is placed on the surface of the forming tool for post-curing process, the post-curing process has no pressure and no vacuum, the temperature is raised to 60℃ at a rate of 1.5℃ / min, then the temperature is raised to 200℃ at a rate of 0.5℃ / min and kept for 15min, the temperature is lowered to 190℃ at a rate of 1.5℃ / min and kept for 8 hours, and the temperature is lowered to 60℃ at a rate of 1.5℃ / min, and the curing is completed.

[0148] The manufacturing method of the long string reinforced wallboard provided by the application, wherein the step 7) is curing and demolding. Specifically, in the curing and demolding step, the first cover plate 5 and the second cover plate 6 are demolded respectively, the first auxiliary material in the inner cavity of the flexible rubber core mold 17 is taken out, the two ends of the flexible rubber core mold 17 are vacuum sealed, the flexible rubber core mold 17 is deformed by vacuumizing, and then the flexible rubber core mold 17 is pulled out from the long string inner cavity manually, and the second auxiliary material is taken out after the flexible rubber core mold 17 is pulled out.

[0149] In the step 7), the first auxiliary material specifically includes the pneumatic outer surface vacuum bag 9 and the first sealing rubber strip 10.

[0150] In the step 7), the second auxiliary material in the inner cavity of the flexible rubber core mold 17 is further taken out, the second auxiliary material includes the tubular vacuum bag 14, the second peelable cloth 15 and the second non-porous isolation film 16, and specifically, the auxiliary material in the flexible rubber core mold 17 is separated from the inner cavity of the flexible rubber core mold 17 by the method of rotating multiple times, and then the auxiliary material is pulled out.

[0151] In the step 7), the vacuum sealing of the two ends of the flexible rubber core mold 17 includes that one end of the flexible rubber core mold 17 is sealed by the second sealing rubber strip and the vacuum bag, the other end of the flexible rubber core mold 17 is sealed by the third sealing rubber strip, the vacuum bag and the air-permeable sealing bag, the inside is provided with a vacuum nozzle base, the flexible rubber core mold 17 is deformed to 40% to 50% of the original size by vacuumizing, and preferably 50%. Then the flexible rubber core mold 17 is pulled out from the long string inner cavity manually, and the third auxiliary material at the two ends is taken out after the flexible rubber core mold 17 is pulled out. The third auxiliary material includes the second sealing rubber strip, the third sealing rubber strip, the vacuum bag, the air-permeable sealing bag and the like.

[0152] The beneficial effects of the application are further illustrated by the following examples.

[0153] In order to make the invention purpose, technical scheme and beneficial technical effects of the application more clear, the application is further described in detail by combining with the examples. However, it should be understood that the examples of the application are only for explaining the application, and are not intended to limit the application, and the examples of the application are not limited to the examples given in the specification. The specific experimental conditions or operation conditions not mentioned in the examples are made according to the conventional conditions or the conditions recommended by the material suppliers.

[0154] Furthermore, it should be understood that the combination of one or more steps of the methods mentioned in the present application does not exclude that other steps of the methods can exist before and after the mentioned combination steps or other steps of the methods can be inserted between the explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection between one or more devices / apparatuses mentioned in the present application does not exclude that other devices / apparatuses can exist before and after the mentioned combination devices / apparatuses or other devices / apparatuses can be inserted between the explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of the steps of the methods is only a convenient tool to identify the steps of the methods, and is not intended to limit the arrangement order of the steps of the methods or to define the scope of the present application, and the change or adjustment of the relative relationship, without substantial change of the technical content, is also regarded as the scope of the present application that can be implemented.

[0155] In the following examples, the reagents, materials and instruments used are commercially available unless otherwise specified.

[0156] Example 1

[0157] Preparation method of the core mold assembly 1:

[0158] 1. First, the inner core mold injection molding tool inner cavity 21 was prepared, and a release agent was brushed; after the release agent was dried, a metal chain 111 was placed in the tool, the metal chain 111 was fixed after being stretched straight, and the inner core mold injection molding tool 2 was combined after the position of the metal chain 111 was fixed; the prepared liquid rubber was poured into the inner cavity of the inner core mold injection molding tool; it was placed at room temperature for at least 24 hours to solidify, and then the inner core mold injection molding tool 2 was removed after solidification, the solidified inner core mold 11 was demolded, and the inner core mold 11 was obtained.

[0159] 2. A first non-porous isolation film 12 with a thickness of 25 um was wrapped on the outer surface of the inner core mold 11;

[0160] 3. A first peelable cloth 13 with a thickness of 0.125 mm was wrapped on the outer surface of the first non-porous isolation film 12;

[0161] 4. The inner core mold 11 wrapped with the first peelable cloth 13 was placed in a tubular vacuum bag 14, a second peelable cloth 15 with a thickness of 0.125 mm was wrapped outside the tubular vacuum bag 14, a second non-porous isolation film 16 with a thickness of 25 um was wrapped outside the second peelable cloth 15 to obtain an inner core mold unit; (as shown in Figure 13

[0162] 5. The inner core mold unit was placed in the rubber inner cavity of the flexible rubber core mold 17 by artificial dragging to obtain the core mold assembly 1.

[0163] Comparative Example 1 ​

[0164] Method for preparing the core mold assembly 1:

[0165] 1. First, the inner core mold cavity 21 of the inner core mold injection molding tooling is prepared, and a release agent is applied. After the release agent is dry, the metal chain 111 is placed in the tooling, and the metal chain 111 is fixed after being stretched straight. After the position of the metal chain 111 is fixed, the inner core mold injection molding tooling 2 is assembled. The prepared liquid rubber is poured into the inner core mold injection molding tooling cavity 21. After being placed at room temperature for at least 24 hours, the inner core mold injection molding tooling 2 is disassembled, and the cured inner core mold 11 is demolded to obtain the inner core mold 11.

[0166] 2. The inner core mold 11 is placed in the rubber inner cavity of the flexible rubber core mold 17 by artificial dragging to obtain the core mold assembly 1.

[0167] Example 2

[0168] 1. The preparation of the net size stringer 3 is completed by manually laying the stringer and automatically cutting the stringer by ultrasonic. The size of the net size stringer 3 is that the stringer height is 30 mm, the cap bottom and cap top arc radius is 5 mm, the cap waist and cap top angle is 120°, and the stringer edge chamfer is 45°. The net size stringer 3 is turned over to the inner cavity of the negative mold forming tooling 4, and the stringer cap top 31 is aligned with the cap top area 41 of the negative mold tooling, the stringer cap waist 32 is aligned with the cap waist area 42 of the negative mold tooling, and the stringer edge 33 is aligned with the edge area of the negative mold tooling, so as to ensure the accurate assembly position of the stringer 3.

[0169] 2. The core mold assembly 1 assembled in example 1 is positioned and placed in the inner cavity of the stringer by using the groove 7.

[0170] 3. The stringer strip 8 is assembled into the inner cavity of the stringer by laser projection positioning. A temporary vacuum bag is sleeved on the outer surface of the stringer 3 and is compacted to ensure that the flexible rubber core mold 17 matches the inner cavity of the stringer well. After assembly is completed, the cap bottom part of the rubber core mold is flush with the plane of the stringer strip 8 and the part of the stringer edge 33 and the skin laying area of the forming negative mold tooling.

[0171] 4. The first cover plate 5 is assembled in the cover plate groove 46 of the stringer end negative mold forming tooling 4. The structure of the first cover plate is shown in Figure 19 The first cover plate 5 includes a rubber core mold fitting part 51, the rubber core mold fitting part includes a connected first fitting part 511 and a second fitting part 512, and the two sides of the rubber core mold fitting part are respectively provided with a fixing part 52. Each fixing part is respectively provided with a fixing hole 54. Each fixing part 52 is connected with the rubber core mold fitting part 51 through the cover plate R area 53. The thickness of the first fitting part 511 is equal. The thickness of the second fitting part 512 gradually decreases.

[0172] 5. Use the automatic fiber placement machine to lay the skin on the skin laying area 45 of the assembled female mold forming tool, the stringer bead 33 area, and the rubber core mold cap bottom area. The fiber placement angle is according to the angle specified in the drawing. The fiber placement gap should meet the design drawing requirements. After the fiber placement is completed, the inner core mold 11 is removed, and the first non-porous release film 12 and the first peelable cloth 13 wrapped around the inner core mold 11 are removed. Figure 12

[0173] 6. Use the pin positioning assembly to assemble the second cover plate 6 on the outer surface of the skin. Paste the first sealing tape 10 in the tool bag area. Connect the tubular vacuum bag 14 inside the rubber core mold with the pneumatic outer surface vacuum bag 9. Ensure that the curing pressure inside the rubber core mold and outside the outer vacuum bag is the same during the curing process. The second cover plate 6 can be purchased and prepared using the preparation method of the second cover plate in the specific embodiment of the present application.

[0174] 7. After curing, remove the auxiliary materials such as the pneumatic outer surface vacuum bag 9 and the first sealing tape 10. Remove the second cover plate 6 and the first cover plate 5. Remove the auxiliary materials such as the tubular vacuum bag 14, the second peelable cloth 15, and the second non-porous release film 16 inside the flexible rubber core mold 17. Separate the auxiliary materials inside the flexible rubber core mold 17 from the inner cavity of the flexible rubber core mold 17 by rotating multiple times, and then pull out the auxiliary materials. Seal one side of the flexible rubber core mold 17 with the second sealing tape and the vacuum bag (as shown in Figure 10 ). Note that the inner cavity of the flexible rubber core mold 17 is sealed, and the other side is sealed with the third sealing tape and the vacuum bag air permeable bag. Place a vacuum nozzle base inside (as shown in Figure 9 ). Deform the flexible rubber core mold 17 to about 40-50% of the original size by vacuuming, and then pull out the flexible rubber core mold 17 from the stringer cavity by artificial pulling (as shown in Figure 11 ). After the flexible rubber core mold 17 is removed, remove the auxiliary materials at both ends.

[0175] Test results:

[0176] 1. The appearance of the wallboard in Example 2

[0177] 1) Although the flexible rubber core mold will deform to 40-50% of the original size during the demolding process, as shown in the parts of Figure 7 and 8 , the flexible rubber core mold will recover to perfect condition after demolding using this assembly method. The stringer end does not have defects such as delamination, and the surface quality of the stringer cavity is good.

[0178] 2) Visually inspect the appearance quality of the wallboard as shown in Figure 14 ​There is no glue tumor, no damage to the fiber, no fiber splitting, no inclusion, no fiber bending, and no edge delamination in the hat bottom.

[0179] 2. Thickness measurement

[0180] The thickness of the wallboard of Example 2 was measured using a magnetic thickness gauge (one-point calibration). The wallboard was spaced 250 mm along the heading, and 13 thickness measurement points were arranged according to Figure 15.

[0181] The nominal thickness of the stringer plane area is 1.683 mm; the tolerance is ±8% mm; and the single value acceptance value is 1.548-1.817 mm. The stringer plane thickness meets the requirements.

[0182] Table 1 Stringer Plane Area Thickness

[0183]

[0184] Stringer Hat Waist R Area

[0185] The nominal thickness of the stringer hat waist R area is 1.683 mm; the single value tolerance is ±15% mm; and the average value tolerance is ±10% mm. The single value acceptance value is 1.431-1.935 mm, and the average value acceptance value is 1.515-1.851 mm. The stringer hat waist R area thickness meets the requirements.

[0186] Table 2 Stringer Hat Waist R Area Thickness

[0187]

[0188] The stringer plane area thickness and the R area thickness were detected using a magnetic thickness gauge. The nominal thickness of the stringer plane area is 1.683 mm; the tolerance is ±8% mm; and the single value acceptance value is 1.548-1.817 mm, and the S2, S3, and S4 thicknesses are qualified. The nominal thickness of the stringer hat waist R area is 1.683 mm; the single value tolerance is ±15%; and the average value tolerance is ±10%. The single value acceptance value is 1.431-1.935 mm, and the average value acceptance value is 1.515-1.851 mm. The stringer hat waist R area thickness meets the requirements.

[0189] The appearance quality is qualified, and the above data show that the use of this kind of rubber core mold combination can ensure the quality of the stringer inner cavity.

[0190] 3、 Figure 16 is the metallographic sample of Example 2, Figure 17 is the result after microscope imaging of Example 2. The Olympus DSX1000 microscope was used to observe the internal quality of the stringer and the skin, and it can be seen from the metallographic result that the fiber state of the stringer hat top and hat waist is good, and the thickness is uniform.

[0191] 4. Ultrasonic detection

[0192] The wallboard prepared in Example 2 was tested according to the test standard CPS8211H, the acceptance standard W538RP152, the test specification MIS-Q0001_A, the test procedure IR-Q5391W20301S200_Draft, and the test method ATTU+MPE. The test results are shown in Table 1. Figure 18 The test results are qualified and meet the acceptance requirements of the W538RP152 specification.

[0193] The above examples are only illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for manufacturing a long-string reinforced wall panel, characterized in that, The method comprises the following steps: 1) Turn the net size stringer into the female mold forming tool; the net size stringer comprises a stringer cap top, two symmetrically distributed stringer cap waists and two symmetrically distributed stringer edge strips; 2) Place the core mold assembly into the inner cavity of the net size stringer; the core mold assembly comprises an inner core mold unit and a flexible rubber core mold, the inner core mold unit comprises an inner core mold and a first non-porous isolation film, a first peelable cloth, a tubular vacuum bag, a second peelable cloth and a second non-porous isolation film which are sequentially wrapped on the outer surface of the inner core mold; the flexible rubber core mold comprises a rubber inner cavity, and the inner core mold unit is arranged in the rubber inner cavity; the inner core mold comprises a metal part, and the outer surface of the metal part is wrapped with rubber; 3) Fill the remaining gap in the inner cavity of the stringer with a twist strip by laser projection positioning, wrap a temporary vacuum bag on the outer surface of the stringer and compact it, and the cap bottom of the assembled rubber core mold, the twist strip, the stringer edge strip and the skin laying area of the female mold forming tool are flush; 4) The end of the net size stringer is provided with a first cover plate, and the female mold forming tool is provided with a cover plate groove matched with the first cover plate; the first cover plate is arranged in the cover plate groove; 5) Lay the skin on the skin laying area of the female mold forming tool, the stringer edge strip area and the cap bottom area of the flexible rubber core mold, and form a skin after the laying is completed; remove the inner core mold, the first non-porous isolation film and the first peelable cloth; 6) Fix a second cover plate on the outer surface of the stringer skin, the second cover plate is provided with a pneumatic outer surface vacuum bag, the pneumatic outer surface vacuum bag is sealed with the second cover plate by a first sealing rubber strip, and the tubular vacuum bag is communicated with the pneumatic outer surface vacuum bag; 7) After curing, demold, and in the demolding step, remove the first auxiliary material, demold the first cover plate and the second cover plate respectively, remove the second auxiliary material in the inner cavity of the flexible rubber core mold, vacuum seal the two ends of the flexible rubber core mold, deform the flexible rubber core mold by vacuumizing, then manually drag the flexible rubber core mold out of the inner cavity of the stringer, remove the third auxiliary material after the flexible rubber core mold is taken out, and deform the flexible rubber core mold to 40%-50% of the original size by vacuumizing.

2. The method of manufacturing a stringer-stiffened panel of claim 1, wherein, The metal part is a metal chain; And / or, the thickness of the first non-porous isolation film is 15um-50um; And / or, the thickness of the first peelable cloth is 0.1mm-0.4mm; And / or, the width of the tubular vacuum bag is 101mm; the thickness is 50um-75um; And / or, the thickness of the second peelable cloth is 0.1mm-0.4mm; And / or, the thickness of the second non-porous isolation film is 15um-50um.

3. The method of manufacturing a long stringer-stiffened panel according to any one of claims 1 to 2, wherein The preparation method of the core mold assembly comprises the following steps: S1 Wrap a layer of first non-porous isolation film on the outer surface of the inner core mold; S2 Wrap a layer of first peelable cloth on the outer surface of the first non-porous isolation film; S3 Place the inner core mold wrapped with the first peelable cloth into the tubular vacuum bag, wrap a layer of second peelable cloth on the outer surface of the tubular vacuum bag, wrap a layer of second non-porous isolation film on the outer surface of the second peelable cloth to obtain an inner core mold unit; S4 places the inner core mold unit into the rubber inner cavity of the flexible rubber core mold to obtain a core mold assembly.

4. The method of manufacturing a stringer-stiffened panel of claim 3, wherein, The preparation method of the inner core mold comprises: a. brushing a release agent in the inner cavity of the inner core mold injection molding tooling; b. after the release agent is dried, a metal part is placed in the inner core mold injection molding tooling, and the metal part is fixed; c. pouring liquid rubber into the inner cavity of the inner core mold injection molding tooling; d. curing at room temperature, and after curing is completed, the inner core mold injection molding tooling is disassembled, and the cured inner core mold is demolded.

5. The method of manufacturing a stringer-stiffened panel of claim 4, wherein, In step b, the metal part is a metal chain; And / or, in step d, the curing time is at least 24 h.

6. The method of manufacturing a long stringer-stiffened panel of claim 1, wherein, In step 1), the longerons are laid up and cut to obtain net size longerons; And / or, the longeron cap top and the two longeron cap waists form a longeron inner cavity; the female mold forming tooling comprises a female mold tooling cap top region, two female mold tooling cap waist regions and two female mold tooling edge strip regions, and the female mold tooling cap top region and the two female mold tooling cap waist regions form a longeron accommodating cavity; wherein the longeron cap top is aligned with the female mold tooling cap top region, the longeron cap waist is aligned with the female mold tooling cap waist region, and the longeron edge strip is aligned with the female mold tooling edge strip region.

7. The method of manufacturing a long stringer-stiffened panel of claim 1, wherein, The vacuum sealing of both ends of the flexible rubber core mold comprises sealing one end of the flexible rubber core mold with a second sealing rubber strip and a vacuum bag, and sealing the other end of the flexible rubber core mold with a third sealing rubber strip, a vacuum bag and a vacuum bag air-permeable sealing bag, and the inside is provided with a vacuum nozzle base; And / or, the first auxiliary material comprises a pneumatic outer surface vacuum bag and a first sealing rubber strip; And / or, the second auxiliary material comprises a tubular vacuum bag, a second peelable cloth and a second non-porous release film; And / or, the third auxiliary material comprises a second sealing rubber strip, a third sealing rubber strip, a vacuum bag and a vacuum bag air-permeable sealing bag.

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