Aerodynamic contoured composite cover plate and method of making same

Abstract

The application relates to a kind of aerodynamic profile composite cover plates and preparation methods thereof.The aerodynamic profile composite cover plate comprises first tooling fabric layer, second tooling fabric layer, third tooling fabric layer and fourth tooling fabric layer arranged in sequence.The aerodynamic profile composite cover plate of hat-shaped stringer stiffened co-cured wall plate can ensure the surface quality of hat-shaped stringer stiffened co-cured wall plate aerodynamic profile surface is good.In addition, the aerodynamic profile composite cover plate mentioned in the application can be used repeatedly, and has high operability, good stability, and can effectively reduce the cost of auxiliary materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of long string reinforced co-cured wallboard preparation, in particular to a pneumatic shape surface composite cover plate and a preparation method thereof. BACKGROUND

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

[0003] The existing pneumatic shape surface does not use a cover plate. If the pneumatic shape surface does not use a hard cover plate, the product pneumatic shape surface stringer cap bottom area after curing will have a pit, poor skin surface quality, and unqualified thickness (such as Figure 2 ). It seriously affects the product quality and reduces the production efficiency. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a pneumatic shape surface composite cover plate and a preparation method thereof, which solves the problems in the prior art.

[0005] To achieve the above-mentioned purposes and other related purposes, one aspect of the present application provides a pneumatic shape surface composite cover plate, which comprises first, second, third and fourth tooling fabric layers arranged in sequence. The content of resin in the first tooling fabric layer is 45% to 50%; the content of resin in the second tooling fabric layer is 35% to 40%; the content of resin in the third tooling fabric layer is 35% to 40%; and the content of resin in the fourth tooling fabric layer is 45% to 50%.

[0006] In some embodiments of the present application, the layup angle of the first tooling fabric layer is 0°, +90° or -90°.

[0007] In some embodiments of the present application, the thickness of the first tooling fabric layer is 0.2mm to 0.3mm.

[0008] In some embodiments of the present application, the ply angle of the second tool fabric layer is +45° or -45°.

[0009] In some embodiments of the present application, the thickness of the second tool fabric layer is 0.6mm-0.7mm.

[0010] In some embodiments of the present application, the ply angle of the third tool fabric layer is +45° or -45°.

[0011] In some embodiments of the present application, the thickness of the third tool fabric layer is 0.6mm-0.7mm.

[0012] In some embodiments of the present application, the ply angle of the fourth tool fabric layer is 0°, +90° or -90°.

[0013] In some embodiments of the present application, the thickness of the fourth tool fabric layer is 0.2mm-0.3mm.

[0014] Another aspect of the present application provides a method for preparing the aerodynamic surface composite cover plate, comprising the following steps:

[0015] S1: brushing a release agent on the cover plate forming tool, and then pasting a first tool fabric prepreg on the surface of the cover plate forming tool after the release agent is completely dried, and then pre-compacting after the pasting to obtain a first pre-compacted tool fabric;

[0016] S2: pasting a second tool fabric prepreg on the first pre-compacted tool fabric provided in step S1, and then pre-compacting after the pasting to obtain a second pre-compacted tool fabric;

[0017] S3: pasting a third tool fabric prepreg on the second pre-compacted tool fabric provided in step S2, and then pre-compacting after the pasting to obtain a third pre-compacted tool fabric;

[0018] S4: pasting a fourth tool fabric prepreg on the third pre-compacted tool fabric provided in step S3, and then pre-compacting after the pasting to obtain a fourth pre-compacted tool fabric;

[0019] S5: placing the pre-compacted tool fabrics into a vacuum bag for sealing;

[0020] S6: pre-solidifying first, then unpacking and demolding after the pre-solidification, and then post-solidifying to obtain the aerodynamic surface composite cover plate.

[0021] In some embodiments of the present application, in step S1, the pre-compacting time is not less than 15min, and the pre-compacting vacuum degree is less than -80KPa.

[0022] In some embodiments of the present application, the resin content in the first tooling fabric prepreg in step S1 is 45% to 50%.

[0023] In some embodiments of the present application, the ply angle of the first tooling fabric prepreg in step S1 is 0°, +90° or -90°.

[0024] In some embodiments of the present application, the compaction time in the pre-compaction process in step S2 is not less than 15 minutes, and the compaction vacuum degree is less than -80 KPa.

[0025] In some embodiments of the present application, the resin content in the second tooling fabric prepreg in step S2 is 35% to 40%.

[0026] In some embodiments of the present application, the ply angle of the second tooling fabric prepreg in step S2 is +45° or -45°.

[0027] In some embodiments of the present application, the compaction time in the pre-compaction process in step S3 is not less than 15 minutes, and the compaction vacuum degree is less than -80 KPa.

[0028] In some embodiments of the present application, the resin content in the third tooling fabric prepreg in step S3 is 35% to 40%.

[0029] In some embodiments of the present application, the ply angle of the third tooling fabric prepreg in step S3 is +45° or -45°.

[0030] In some embodiments of the present application, the compaction time in the pre-compaction process in step S4 is not less than 15 minutes, and the compaction vacuum degree is less than -80 KPa.

[0031] In some embodiments of the present application, the resin content in the fourth tooling fabric prepreg in step S4 is 45% to 50%.

[0032] In some embodiments of the present application, the ply angle of the fourth tooling fabric prepreg in step S4 is 0°, +90° or -90°.

[0033] In some embodiments of the present application, the pre-curing pressure in step S6 is 0.4 Mpa to 0.7 Mpa, the curing process is carried out under vacuum, the temperature is raised to 60°C to 63°C at a temperature raising rate of 0.5°C / min to 1.0°C / min, and the temperature is kept for 16 to 17 hours.

[0034] In some embodiments of the present application, the post-curing process is pressureless and vacuumless; the temperature is raised to 60-63 DEG C at a rate of 1-2 DEG C / min, then raised to 200-203 DEG C at a rate of 0.3-0.5 DEG C / min for 15-20 min, then lowered to 190 DEG C at a rate of 1-2 DEG C / min, and kept for 8 hours, then lowered to room temperature at a rate of no more than 3.0 DEG C / min, and the curing is completed.

[0035] In another aspect of the present application, the use of the aerodynamic profile composite cover plate in the preparation of the stringer co-cured wall panel is provided.

[0036] In another aspect of the present application, a processing technology of the stringer co-cured wall panel is provided, comprising the following steps:

[0037] 1) assembling the inner core mold and the flexible rubber core mold to obtain an inner core mold and flexible rubber core mold assembly;

[0038] 2) turning the net size stringer into the negative 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;

[0039] 3) placing the inner core mold and flexible rubber core mold assembly of step 1) into the inner cavity of the net size stringer;

[0040] 4) filling the remaining gaps in the inner cavity of the stringer with the twist strip by laser projection positioning, and setting a temporary vacuum bag on the outer surface of the stringer and compacting; the cap bottom of the rubber core mold, the twist strip, the stringer edge strip, and the skin laying area of the negative mold forming tool are flush after assembly;

[0041] 5) the end of the net size stringer is provided with a hard cover plate; the negative mold forming tool is provided with a cover plate groove matched with the hard cover plate; the hard cover plate is arranged in the cover plate groove;

[0042] 6) performing skin laying on the skin laying area of the negative mold forming tool, the edge strip area of the stringer, and the cap bottom area of the flexible rubber core mold; after the laying is completed, a skin is formed, and the inner core mold is removed;

[0043] 7) fixing the aerodynamic profile composite cover plate as described in the present application on the outer surface of the skin; the aerodynamic profile composite cover plate is provided with an external vacuum bag, the external vacuum bag and the aerodynamic profile composite cover plate are sealed by a first sealing rubber strip, and a tubular vacuum bag is communicated with the external vacuum bag;

[0044] 8) demolding after curing.

[0045] Compared with the prior art, the present application has the following beneficial effects:

[0046] The hat-shaped long stringer reinforced co-cured wallboard aerodynamic surface composite cover plate provided by the application can ensure that the hat-shaped long stringer reinforced co-cured wallboard aerodynamic surface has good surface quality. In addition, the aerodynamic surface composite cover plate provided by the application can be repeatedly used, has strong operability and good stability, and can effectively reduce the cost of auxiliary materials.

[0047] The processing technology of the hat-shaped long stringer reinforced wallboard provided by the application can realize that the curing pressure of the long stringer inner cavity and the skin outer part is consistent through the communication between the inner tubular vacuum bag and the outer vacuum bag of the rubber core mold, so that the surface quality of the long stringer inner cavity and the uniformity of the long stringer thickness can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The figure is a schematic diagram of the layered structure of the aerodynamic composite cover plate provided by the application.

[0049] Figure 2 The figure is a schematic diagram of the co-cured hat-shaped long stringer reinforced wallboard aerodynamic surface unqualified problem (skin pit, thickness out of tolerance) that needs to be solved by the application.

[0050] Figure 3 The figure is a sectional view of the hat-shaped long stringer reinforced co-cured wallboard mentioned in the application.

[0051] Figure 4 The figure is a schematic diagram of the co-cured hat-shaped long stringer reinforced wallboard forming tool provided by the application.

[0052] Figure 5 The figure is a schematic diagram of the hat-shaped long stringer end cover plate and tool provided by the application.

[0053] Figure 6 The figure is a sectional view of the co-cured hat-shaped long stringer reinforced wallboard in the skin laying process provided by the application.

[0054] Figure 7 The figure is a schematic diagram of the final bag sealing provided by the application.

[0055] Figure 8 The figure is a schematic diagram of the structure of the hard cover plate provided by the application.

[0056] Figure 9 The figure is a wallboard physical map of Comparative Example 1 without using the composite cover plate provided by the application. Figure 9 a is the skin aerodynamic surface, Figure 9 b is the long stringer surface.

[0057] Figure 10 The figure is a wallboard appearance physical map of Example 2 using the composite cover plate provided by the application. Figure 10 a is the skin aerodynamic surface, Figure 10 b is the long stringer surface.

[0058] Figure 11Ultrasonic detection diagram of the wallboard prepared by the present application.

[0059] Figure 12 Thickness measurement point diagram of the wallboard prepared by the present application. BRIEF DESCRIPTION OF DRAWINGS

[0061] 1 Forming tool stringer cap top area

[0062] 2 Forming tool stringer cap top R angle area

[0063] 3 Forming tool stringer cap waist area

[0064] 4 Forming tool stringer bead area

[0065] 5 Skin laying area

[0066] 6 Cover plate groove

[0067] 7 Forming tool stringer outer rubber core mold groove

[0068] 8 Forming tool sealant strip area groove

[0069] 9 Hard cover plate

[0070] 91 Rubber core mold bonding part

[0071] 911 First bonding part

[0072] 912 Second bonding part

[0073] 92 Retaining part

[0074] 93 Cover plate R area

[0075] 94 Retaining hole

[0076] 10 Negative mold forming tool

[0077] 11 Stringer cap top

[0078] 12 Stringer cap waist

[0079] 13 Stringer bead

[0080] 14 Skin

[0081] 15 Twisted thread strip

[0082] 16 Flexible rubber core mold

[0083] 17 Aerodynamic profiled composite cover plate

[0084] 171 First tool fabric layer

[0085] 172 Second tool fabric layer

[0086] 173 Third tooling fabric layer

[0087] 174 Fourth tooling fabric layer

[0088] 18 Inner Core Mold

[0089] 19 Metal chains

[0090] 20 First sealing strip

[0091] 21. Angled area of ​​the forming tooling stringer

[0092] 22 External vacuum bags

[0093] 23 Tubular Vacuum Bags

[0094] 24 Automatic filament placement machine pressure rollers Detailed Implementation

[0095] 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.

[0096] 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.

[0097] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0098] The present application is unexpectedly found through a large number of experiments that a kind of aerodynamic shape composite cover plate is applied to the processing technology of long string stiffening co-curing wallboard, which can ensure that the surface quality of the cap-shaped long string stiffening co-curing wallboard is good. In addition, the composite cover plate mentioned in the present application can be repeatedly used, and has strong operability and good stability, which can effectively reduce the cost of auxiliary materials. On this basis, the present application is completed.

[0099] The present application provides an aerodynamic shape composite cover plate in one aspect, which comprises a first tooling fabric layer 171, a second tooling fabric layer 172, a third tooling fabric layer 173 and a fourth tooling fabric layer 174 arranged in sequence. Figure 1 The content of resin in the first tooling fabric layer 171 can be 45% to 50%, 45% to 48%, or 48% to 50%, etc. The content of resin in the second tooling fabric layer 172 can be 35% to 40%, 35% to 38%, or 38% to 40%, etc. The content of resin in the third tooling fabric layer 173 can be 35% to 40%, 35% to 38%, or 38% to 40%, etc. The content of resin in the fourth tooling fabric layer 174 can be 45% to 50%, 45% to 48%, or 48% to 50%, etc.

[0100] In the aerodynamic shape composite cover plate provided by the present application, the layup angle of the first tooling fabric layer 171 is generally 0°, +90° or -90°. Generally, the 0° direction of the part is defined as the 0° direction of the cover plate based on the spatial coordinate system of the part. The thickness of the first tooling fabric layer 171 can be 0.2mm to 0.3mm, 0.2mm to 0.23mm, or 0.23mm to 0.3mm, etc. The resin in the first tooling fabric layer 171 can be, for example, epoxy resin. In addition to the resin, the other components of the first tooling fabric layer 171 include carbon fiber fabric.

[0101] In the aerodynamic shape composite cover plate provided by the present application, the layup angle of the second tooling fabric layer 172 is +45° or -45°. Generally, the 0° direction of the part is defined as the 0° direction of the cover plate based on the spatial coordinate system of the part. Wherein +45° means that the 0° direction of the part is deflected clockwise by 45°. -45° means that the 0° direction of the part is deflected counterclockwise by 45°. The thickness of the second tooling fabric layer 172 can be 0.6mm to 0.7mm, 0.6mm to 0.65mm, or 0.65mm to 0.7mm, etc. The resin in the second tooling fabric layer 172 can be, for example, epoxy resin. In addition to the resin, the other components of the second tooling fabric layer 172 include carbon fiber fabric.

[0102] In the aerodynamic profile surface composite cover plate provided by the application, the laying angle of the third tool fabric layer 173 is +45° or -45°. 45° means that the 0° direction of the part is deflected clockwise by 45°. -45° means that the 0° direction of the part is deflected counterclockwise by 45°. The thickness of the third tool fabric layer 173 can be 0.6mm-0.7mm, 0.6mm-0.65mm, or 0.65mm-0.7mm, etc. The resin in the third tool fabric layer 173 can be, for example, epoxy resin. In addition to the resin, the other components of the third tool fabric layer 173 include carbon fiber fabric. The reason why the second tool fabric layer and the third tool fabric layer are divided into two layers in the application is that if the thickness is too thick, such as the laying thickness exceeds 1mm, gas will be generated during laying, and the gas in the layer cannot be discharged, which will cause the cover plate to have dense pores or delamination.

[0103] In the aerodynamic profile surface composite cover plate provided by the application, the laying angle of the fourth tool fabric layer 174 is 0°, +90° or -90°. 0° means that the 0° direction of the part is defined as the 0° direction of the cover plate based on the spatial coordinate system of the part. +90° means that the 0° direction of the part is deflected clockwise by 90°, and -90° means that the 0° direction of the part is deflected counterclockwise by 90°. The thickness of the fourth tool fabric layer 174 can be 0.2mm-0.3mm, 0.2mm-0.23mm, or 0.23mm-0.3mm, etc. The resin in the fourth tool fabric layer 174 can be, for example, epoxy resin. In addition to the resin, the other components of the fourth tool fabric layer 174 include carbon fiber fabric.

[0104] The advantages of laying the first tool fabric layer 171, the second tool fabric layer 172, the third tool fabric layer 173 and the fourth tool fabric layer 174 according to the above angles are that the cover plate will not deform obviously after curing and demolding, and will not deform after long-term use. The advantages of laying the first tool fabric layer 171, the second tool fabric layer 172, the third tool fabric layer 173 and the fourth tool fabric layer 174 according to the above thicknesses are to ensure that the inner and outer surface quality and internal quality of the cover plate are good, and no defects such as pores or poor glue appear.

[0105] The application also provides a preparation method of an aerodynamic profile surface composite cover plate, which comprises the following steps:

[0106] S1: The cover plate forming tool is brushed with a demolding agent, and after the demolding agent is completely dried, a first tool fabric prepreg is laid on the surface of the cover plate forming tool. After laying is completed, pre-compaction is performed to obtain a first pre-compacted tool fabric;

[0107] S2: laying a second tool fabric prepreg on the first pre-compacted tool fabric provided in step S1, and pre-compacting after the laying to obtain a second pre-compacted tool fabric;

[0108] S3: laying a third tool fabric prepreg on the second pre-compacted tool fabric provided in step S2, and pre-compacting after the laying to obtain a third pre-compacted tool fabric;

[0109] S4: laying a fourth tool fabric prepreg on the third pre-compacted tool fabric provided in step S3, and pre-compacting after the laying to obtain a fourth pre-compacted tool fabric;

[0110] S5: placing the pre-compacted tool fabrics into a vacuum bag for sealing;

[0111] S6: pre-solidifying first, unpacking and demolding after the pre-solidifying, and then post-solidifying to obtain the aerodynamic profile composite cover plate 17.

[0112] In the method for preparing the aerodynamic profile composite cover plate, step S1 is to brush a release agent on a cover plate forming tool, and after the release agent is completely dried, a first tool fabric prepreg is laid on the surface of the cover plate forming tool, and pre-compacting is performed after the laying to obtain a first pre-compacted tool fabric. Specifically, the content of resin in the laid first tool fabric prepreg can be 45% to 50%, 45% to 48%, or 48% to 50%, etc. The laying angle is 0°, +90° or -90°, and the laying angle is explained as above. After the laying of the first tool fabric prepreg is completed, a temporary vacuum bag is sealed for pre-compacting, the pre-compacting time is not less than 15 min, and the pre-compacting vacuum degree is less than -80 KPa. Preferably, the pre-compacting time is 30 min. The pre-compacting vacuum degree is -95 KPa. In some embodiments, the first tool fabric prepreg is purchased from GE15 / W-3021 of Guangwei Composite.

[0113] In the method for preparing the aerodynamic profile composite cover plate, step S2 is to lay a second tool fabric prepreg on the first pre-compacted tool fabric provided in step S1, and pre-compacting after the laying to obtain a second pre-compacted tool fabric. Specifically, the content of resin in the laid second tool fabric prepreg can be 35% to 40%, 35% to 38%, or 38% to 40%, etc. The laying angle is +45° or -45°, and the laying angle is explained as above. It should be noted that air guiding should be paid attention to during the laying. After the laying of the second tool fabric prepreg is completed, a temporary vacuum bag is sealed for pre-compacting, the pre-compacting time is not less than 15 min, and the pre-compacting vacuum degree is less than -80 KPa. Preferably, the pre-compacting time is 30 min. The pre-compacting vacuum degree is -95 KPa. In some embodiments, the second tool fabric prepreg is purchased from GE15 / W-7021 of Guangwei Composite.

[0114] In the method for preparing the aerodynamic shape composite cover plate, step S3 is to lay the third tool fabric prepreg on the second pre-compacted tool fabric provided in step S2, and pre-compact after the laying is completed to obtain the third pre-compacted tool fabric. Specifically, the content of resin in the laid third tool fabric prepreg can be 35%-40%, 35%-38%, or 38%-40%, etc. The lay-up angle is +45° or -45°, and attention should be paid to air guiding during the lay-up process. The lay-up angle is explained as before. After the third tool fabric prepreg is laid, a temporary vacuum bag is sealed to pre-compact, the compacting time is not less than 15 min, and the compacting vacuum degree is less than -80 KPa. Preferably, the compacting time is 30 min. The compacting vacuum degree is -95 KPa. In some embodiments, the third tool fabric prepreg is purchased from GE15 / W-7021 of Guangwei Composite.

[0115] In the method for preparing the aerodynamic shape composite cover plate, step S4 is to lay the fourth tool fabric prepreg on the third pre-compacted tool fabric provided in step S3, and pre-compact after the laying is completed to obtain the fourth pre-compacted tool fabric. Specifically, the content of resin in the laid fourth tool fabric prepreg can be 45%-50%, 45%-48%, or 48%-50%, etc. The lay-up angle is 0°, +90° or -90°, and the lay-up angle is explained as before. After the fourth tool fabric prepreg is laid, a temporary vacuum bag is sealed to pre-compact, the compacting time is not less than 15 min, and the compacting vacuum degree is less than -80 KPa. Preferably, the compacting time is 30 min. The compacting vacuum degree is -95 KPa. In some embodiments, the fourth tool fabric prepreg is purchased from GE15 / W-3021 of Guangwei Composite.

[0116] In the method for preparing the aerodynamic shape composite cover plate, step S5 is to place each layer of pre-compacted tool fabric into a vacuum bag to seal. Attention should be paid to air guiding during the sealing process, and air guiding filaments are placed in the part excess area, the air guiding filaments contact the edge air guiding fibers, and the surface can be selected to have a porous isolation film or a non-porous isolation film. The selection of the isolation film is determined according to the actual product size and shape, and it is suggested to use a porous isolation film for large-size parts.

[0117] The preparation method of the aerodynamic profile composite cover plate provided by the application comprises the following steps: S1, preparing a flexible rubber core mold 16; S2, preparing an inner core mold 18; S3, assembling the flexible rubber core mold 16 and the inner core mold 18 to obtain an inner core mold and flexible rubber core mold assembly; S4, placing a net size long string into the inner cavity of the inner core mold and flexible rubber core mold assembly; S5, placing the inner core mold and flexible rubber core mold assembly into a negative mold forming tool 10; S6, pre-curing; S7, taking out the bag and demolding after the pre-curing is completed; S8, post-curing; and S9, obtaining the aerodynamic profile composite cover plate 17 after the post-curing is completed.

[0118] The thickness of the cover plate after the twice curing process is 1.6 mm to 2 mm. The composite cover plate provided by the application can ensure that the hat-shaped long string reinforced co-cured wall plate aerodynamic profile surface receives uniform pressure during the curing process, and thus the surface quality of the aerodynamic profile surface is good.

[0119] The application further provides the use of the aerodynamic profile composite cover plate in the preparation of a long string reinforced co-cured wall plate.

[0120] The application further provides a processing technology of a long string reinforced co-cured wall plate, which comprises the following steps:

[0121] 1) assembling an inner core mold 18 and a flexible rubber core mold 16 to obtain an inner core mold and flexible rubber core mold assembly;

[0122] 2) placing a net size long string into a negative mold forming tool 10; the net size long string comprises a long string hat top 11, two symmetrically distributed long string hat waists 12 and two symmetrically distributed long string edge strips 13;

[0123] 3) placing the inner core mold and flexible rubber core mold assembly in step 1) into the inner cavity of the net size long string;

[0124] 4) using laser projection positioning, filling the remaining gap of the inner cavity of the long string 15 with the long string, setting a temporary vacuum bag on the outer surface of the long string and compacting, the cap bottom of the assembled rubber core mold, the long string 15, the long string edge strip 13, and the skin laying area 5 of the female mold forming tool 10 are flush;

[0125] 5) The end of the net size long string is provided with a hard cover plate 9; the female mold forming tool 10 is provided with a cover plate groove 6 matched with the hard cover plate 9; the hard cover plate 9 is arranged in the cover plate groove 6;

[0126] 6) The skin 14 is laid on the skin laying area 5 of the female mold forming tool 10, the edge strip area of the long string, and the cap bottom area of the flexible rubber core mold 16, and the skin 14 is formed after the laying is completed, and the inner core mold 18 is taken out;

[0127] 7) The aerodynamic surface composite cover plate 17 of the preceding application is fixed on the outer surface of the skin 14, the outer vacuum bag 22 is arranged on the aerodynamic surface composite cover plate 17, the outer vacuum bag 22 is sealed with the aerodynamic surface composite cover plate 17 through the first sealing rubber strip 20, and the tubular vacuum bag 23 is communicated with the outer vacuum bag 22;

[0128] 8) After curing, demolding.

[0129] In the processing technology of the long string reinforced co-curing wallboard provided by the application, step 1) is to assemble the inner core mold 18 and the flexible rubber core mold 16 to obtain an inner core mold and flexible rubber core mold assembly. The preparation method of the inner core mold and flexible rubber core mold assembly comprises the following steps: placing the inner core mold 18 in the tubular vacuum bag 23; and placing the tubular vacuum bag 23 in the rubber inner cavity of the flexible rubber core mold 16 to obtain the inner core mold and flexible rubber core mold assembly.

[0130] In the preparation method of the inner core mold and flexible rubber core mold assembly provided by the application, the inner core mold 18 is prepared by pouring liquid rubber mixed according to the required ratio into the inner core mold forming tool, and metal chains 19 are added in the liquid rubber to enhance the rigidity of the inner core mold 18.

[0131] In the processing technology of the long string reinforced co-curing wallboard provided by the application, step 2) is to turn the net size long string into the female mold forming tool 10. The net size long string is obtained by laying and cutting the long string. Specifically, the preparation of the net size long string is completed by manual laying of the long string and ultrasonic automatic cutting. Further, as shown in Figure 3, the net size longeron includes the longeron cap top 11, two symmetrically distributed longeron cap waists 12 and two symmetrically distributed longeron edge strips 13. The two longeron cap waists 12 are respectively connected with the two side edges of the longeron cap top 11. The longeron edge strips 13 are connected with the longeron cap waists 12, so as to form the longeron with the cap-shaped cross section. Specifically, the longeron cap top 11 and the two longeron cap waists 12 enclose the inner cavity of the longeron. As shown in Figure 4 , the female die forming tool 10 includes a forming tool longeron cap top area 1, two forming tool longeron cap waist areas 3 and two forming tool longeron edge strip areas 4, and the forming tool longeron cap top area 1 and the two forming tool longeron cap waist areas 3 are respectively connected through the forming tool longeron cap top R angle area 2. The forming tool longeron cap top area 1, the forming tool longeron cap top R angle area 2 and the two forming tool longeron cap waist areas 3 form a longeron accommodating groove. Among them, the longeron cap top 11 is aligned with the forming tool longeron cap top area 1, the longeron cap waist 12 is aligned with the forming tool longeron cap waist area 3, and the longeron edge strip 13 is aligned with the forming tool longeron edge strip area 4, which can ensure the accurate assembly position of the longeron.

[0132] In the processing technology of the longeron-stiffened co-cured wallboard provided by the application, step 3) is to place the aforementioned inner core mold and flexible rubber core mold assembly of the application into the inner cavity of the net size longeron. The inner core mold and flexible rubber core mold assembly can be prepared by the aforementioned inner core mold and flexible rubber core mold assembly preparation method of the application. During the placement process, the assembled inner core mold and flexible rubber core mold assembly can be positioned and placed into the inner cavity of the longeron by using the groove.

[0133] In the processing technology of the longeron-stiffened co-cured wallboard provided by the application, step 4) is to use laser projection positioning to fill the remaining gaps in the inner cavity of the longeron with the twist strip 15, seal the temporary vacuum bag, press the longeron and compact it, and ensure that the flexible rubber core mold 16 and the inner cavity of the longeron are well matched. After assembly, the cap bottom of the rubber core mold, the twist strip 15, the longeron edge strip 13 and the skin laying area 5 of the female die forming tool 10 are flush.

[0134] In the processing technology of the longeron-stiffened co-cured wallboard provided by the application, as shown in Figure 5 Step 5) is that the end of the net size longeron is provided with a hard cover plate 9. The hard cover plate 9 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 longeron-stiffened co-cured wallboard. For example, it can be a steel cover plate, and more for example, it can be an Invar steel material. The female die forming tool 10 is provided with a cover plate groove 6 matched with the hard cover plate 9; the hard cover plate 9 is arranged in the cover plate groove 6. As shown in Figure 8In an embodiment, the hard cover plate 9 comprises a rubber core mold bonding part 91, which comprises a connected first bonding part 911 and a second bonding part 912, and further comprises a retaining part 92 on each side of the rubber core mold bonding part 91, and a retaining hole 94 is arranged on each retaining part 92; the retaining part 92 and the rubber core mold bonding part 91 are connected through a cover plate R area 93; the thickness of the first bonding part 911 is equal; and the thickness of the second bonding part 912 gradually decreases.

[0135] In the processing technology of the long string reinforced co-cured wall plate provided by the application, Figure 6 Step 6) is to lay the skin 14 on the skin laying area 5 of the female mold forming tool 10, the string area of the long string, and the cap bottom area of the flexible rubber core mold 16, and the skin 14 is formed after the laying is completed, and the inner core mold 18 is taken out. The laying of the skin 14 may be performed on an automatic fiber laying machine, for example. The laying angle is according to the angle specified in the drawing, which may be [-45 / 45 / 45 / 90 / -45 / 0 / -45 / 90 / 45 / 45 / -45], for example. The laying gap should meet the requirements of the design drawing. The laying gap may be ≤1mm, for example.

[0136] In the processing technology of the long string reinforced co-cured wall plate provided by the application, Figure 7 Step 7) is to fix the aerodynamic composite cover plate 17 on the outer surface of the skin 14. The fixing mode may be pin positioning assembly, for example. The outer vacuum bag 22 is sealed with the aerodynamic composite cover plate 17 through the first sealing strip 20, specifically, the first sealing strip 20 is pasted in the tool sealing bag area. The aerodynamic composite cover plate 17 is provided with the outer vacuum bag 22, and the tubular vacuum bag 23 is communicated with the outer vacuum bag 22. The curing pressure in the inner cavity of the rubber core mold and outside the outer vacuum bag 22 is ensured to be the same during the curing process. The surface quality of the inner cavity of the long string is good, and the thickness of the long string is uniform.

[0137] Further, the aerodynamic composite cover plate is the aerodynamic composite cover plate provided by the first aspect of the application.

[0138] In the processing technology of the long string reinforced co-cured wall plate provided by the application, step 8) is demolding after curing. Specifically, in the demolding after curing, the hard cover plate 9 and the aerodynamic composite cover plate 17 are demolded respectively, the first auxiliary material in the inner cavity of the flexible rubber core mold 16 is taken out, the two ends of the flexible rubber core mold 16 are vacuum sealed, the flexible rubber core mold 16 is deformed by vacuumizing, and then the flexible rubber core mold 16 is pulled out from the inner cavity of the long string in a manual pulling manner, and the second auxiliary material is taken out after the flexible rubber core mold 16 is pulled out.

[0139] In step 8) of the present application, specifically, the first auxiliary material includes an external vacuum bag 22 and a first sealant strip 20, etc.

[0140] In step 8) of the present application, further, the second auxiliary material in the inner cavity of the flexible rubber core mold 16 is taken out, the second auxiliary material includes a tubular vacuum bag 23, specifically, the auxiliary material in the flexible rubber core mold 16 is separated from the inner cavity of the flexible rubber core mold 16 by a method of multiple rotations, and then the auxiliary material is taken out by a method of dragging.

[0141] In step 8) of the present application, the vacuum sealing of both ends of the flexible rubber core mold 16 includes sealing one end of the flexible rubber core mold 16 with a second sealant strip and a vacuum bag, sealing the other end of the flexible rubber core mold 16 with a third sealant strip, a vacuum bag air-permeable sealing bag, and a vacuum nozzle base inside for vacuumizing, deforming the flexible rubber core mold 16 to 40% to 50% of the original size, preferably 50%, and then manually dragging the flexible rubber core mold 16 out of the inner cavity of the longeron, and taking out the third auxiliary material at both ends after the flexible rubber core mold 16 is taken out. The third auxiliary material includes a second sealant strip, a third sealant strip, a vacuum bag, a vacuum bag air-permeable sealing bag, etc.

[0142] The beneficial effects of the present application are further illustrated by the following examples.

[0143] In order to make the invention purpose, technical scheme and beneficial technical effects of the present application clearer, the present application is further described in detail by the following examples. However, it should be understood that the examples of the present application are only for the purpose of explaining the present application, and are not intended to limit the present application, and the examples of the present 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.

[0144] In addition, it should be understood that the one or more method steps mentioned in the present application do not exclude that there can be other method steps before and after the combination steps or other method steps can be inserted between the explicitly mentioned steps, unless otherwise stated; it should also be understood that the combination connection relationship between the one or more devices / apparatuses mentioned in the present application does not exclude that there can be other devices / apparatuses before and after the combination devices / apparatuses or other devices / apparatuses can be inserted between the two explicitly mentioned devices / apparatuses, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the arrangement order of each method step or to limit the range of implementation of the present application, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also regarded as the scope of implementation of the present application.

[0145] The reagents, materials and instruments used in the following examples are commercially available unless otherwise specified.

[0146] Example 1

[0147] 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;

[0148] 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;

[0149] 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, and 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;

[0150] 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, and a porous or non-porous isolation film can be selected on the surface, the selection of the isolation film is determined according to the actual product size and shape, and it is recommended to use a porous isolation film for large-sized parts.

[0151] 5. Curing, the curing of this cover plate is a two-step curing process, including pre-curing and post-curing, 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.

[0152] 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.

[0153] 7. The cover plate is placed on the surface of the forming tool for post-curing, the post-curing process is carried out without pressure and 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.

[0154] Example 2

[0155] 1. By pouring the mixed liquid rubber into the inner core mold 18 forming tool, and adding metal chains 19 to the liquid rubber to enhance the stiffness of the inner core mold 18. The inner core mold 18 is placed in the tubular vacuum bag 23; the tubular vacuum bag 23 is placed in the rubber inner cavity of the flexible rubber core mold 16 to obtain the inner core mold and flexible rubber core mold assembly.

[0156] 2. The preparation of the net size stringer is completed by manually laying the stringer and automatically cutting the stringer by ultrasonic. The net size stringer is turned over to the negative mold forming tool 10, and the stringer cap top 11 is aligned with the stringer cap top area 1 of the forming tool, the stringer cap waist 12 is aligned with the cap waist area of the negative mold tool, and the stringer edge strip 13 is aligned with the edge strip area of the negative mold tool, which can ensure the accurate assembly position of the stringer. As shown in Figure 3 and 4 .

[0157] 3. The assembled flexible rubber core mold 16 is placed into the inner cavity of the stringer by positioning with the stringer outer rubber core mold groove 7 of the forming tool.

[0158] 4. The twist strip 15 is assembled into the inner cavity of the stringer by laser projection positioning, a temporary vacuum bag is sealed and compacted, and the rubber core mold and the inner cavity of the stringer are matched perfectly. After assembly, the cap bottom part of the rubber core mold is flush with the plane of the twist strip 15 and the edge strip part of the stringer, and the skin laying area 5 of the negative mold forming tool;

[0159] 5. The hard cover plate 9 is assembled in the groove of the stringer end negative mold forming tool 10. The structure of the hard cover plate 9 is as shown in Figure 8 .

[0160] 6. As shown in Figure 6 , the skin 14 is laid by the automatic fiber laying machine pressure roller 24 on the skin area of the assembled negative mold forming tool 10, the edge strip area of the stringer, and the cap bottom area of the rubber core mold 16. The laying angle is according to the angle specified in the drawing, and the laying gap should meet the design drawing requirements. After laying, the skin 14 is formed, and after laying is completed, the inner core mold 18 is removed.

[0161] 7. As shown in Figure 7 , the pneumatic outer shape composite cover plate 17 prepared in embodiment 1 is assembled by positioning with the pin on the outer surface of the skin 14, the first sealing strip is pasted in the tool bag sealing area, the inner tubular vacuum bag 23 of the rubber core mold is connected with the outer vacuum bag 22, and the curing pressure in the inner cavity of the rubber core mold and outside the outer vacuum bag 22 is ensured to be the same during the curing process.

[0162] 8. After curing, demolding.

[0163] Comparative Example 1

[0164] Compared with Example 2, except that the pneumatic outer surface composite cover plate 17 is not used in step 7, the rest of the steps are the same as in Example 2.

[0165] Test results:

[0166] 1. Appearance

[0167] like Figure 9 Comparative Example 1, which did not use the composite cover plate mentioned in the patent, shows obvious large-area pits along the stringer twist strip area and stringer edge strip edge area on the aerodynamic surface of the part's skin, with the maximum pit depth exceeding 1mm. The stringer tooling surface of the wall panel is free of glue nodules, glue deficiency, scratches damaging the fibers, fiber splitting, and visible inclusions; the fibers are free of bending and wrinkles. Figure 10 Example 2 uses the composite cover plate mentioned in the patent. As can be seen from the following appearance inspection report, the surface quality of the aerodynamic outer surface of the skin is very good, with no dents, and the appearance inspection is qualified. Visual inspection of the appearance quality of the wall panel shows that there are no glue nodules or glue deficiency on the stringer surface of the wall panel, no scratches or fiber splitting that damage the fibers, no inclusions, no bending or wrinkling of the fibers, and no edge delamination at the bottom of the stringer cap.

[0168] 2. Ultrasound report

[0169] The wall panel of Embodiment 2 of this invention was tested according to the following standards: CPS8211H, acceptance standard W538RP152, testing specification MIS-Q0001_A, testing procedure IR-Q5391W20301S200_trial version, and testing method ATTU+MPE. The test results are as follows: Figure 11 The test results are qualified and meet the acceptance requirements of W538RP152 specification.

[0170] from Figure 11 The ultrasonic test report indicates that the non-destructive testing was successful.

[0171] 3. Thickness

[0172] The wall panel thickness of Embodiment 2 of this invention was measured using a magnetic thickness gauge (single-point calibration). The wall panels were spaced 250mm apart along the flight direction, according to... Figure 12 Thirteen thickness measurement points were set up.

[0173] 1) Non-co-cured areas of the skin

[0174] The nominal thickness of the non-co-cured skin area is 2.057 mm; tolerance ±5%; single-value acceptable range: 1.954~2.159 mm. The thickness of the non-co-cured skin area meets the requirements.

[0175] Table 1 Thickness of Non-Co-cured Region of Skin

[0176]

[0177] 2) co-cured area

[0178] The nominal thickness of the co-cured area is 3.740 mm; the tolerance is ±5%; the single acceptance value is 3.553-3.927 mm. The thickness of the co-cured area meets the requirements.

[0179] Table 2 Thickness of co-cured area

[0180]

[0181]

[0182] The hat stringer stiffened panel is manufactured by using the scheme, the thickness of the skin area and the co-cured area is detected by using the magnetic thickness gauge, and the detection results are qualified.

[0183] The above examples only illustrate the principles and effects of the present application, and are not used 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 completed 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 process for manufacturing a stringer-stiffened co-cured wall panel, characterized in that, It comprises the following steps: 1) Assemble the inner core mold and the flexible rubber core mold to obtain an inner core mold and flexible rubber core mold assembly; 2) Turn the net size longeron into the female mold forming tool; the net size longeron comprises a longeron cap top, two symmetrically distributed longeron cap waists, and two symmetrically distributed longeron edge strips; 3) Place the inner core mold and flexible rubber core mold assembly of step 1) into the inner cavity of the net size longeron; 4) Use laser projection positioning to fill the remaining gap in the inner cavity of the twist strip, set a temporary vacuum bag on the outer surface of the longeron, and compact it, so that the cap bottom of the rubber core mold, the twist strip, the longeron edge strip, and the skin laying area of the female mold forming tool are flush after assembly; 5) The end of the net size longeron is provided with a hard cover plate; the female mold forming tool is provided with a cover plate groove matched with the hard cover plate; the hard cover plate is arranged in the cover plate groove; 6) Lay the skin on the skin laying area of the female mold forming tool, the edge strip area of the longeron, 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; 7) Fix a pneumatic aerodynamic composite cover plate on the outer surface of the skin, the pneumatic aerodynamic composite cover plate is provided with an external vacuum bag, the external vacuum bag and the pneumatic aerodynamic composite cover plate are sealed by a first sealing rubber strip, and a tubular vacuum bag is communicated with the external vacuum bag; the pneumatic aerodynamic composite cover plate comprises a first tool fabric layer, a second tool fabric layer, a third tool fabric layer, and a fourth tool fabric layer which are sequentially stacked; the content of resin in the first tool fabric layer is 45%-50%; the content of resin in the second tool fabric layer is 35%-40%; the content of resin in the third tool fabric layer is 35%-40%; the content of resin in the fourth tool fabric layer is 45%-50%; 8) Demold after curing.

2. The process for manufacturing a long stringer co-cured wall panel of claim 1, wherein, The laying angle of the first tool fabric layer is 0°, +90° or -90°; And / or, the thickness of the first tool fabric layer is 0.2mm-0.3mm.

3. The process for manufacturing a long stringer co-cured wall panel of claim 1, wherein, The laying angle of the second tool fabric layer is +45° or -45°; And / or, the thickness of the second tool fabric layer is 0.6mm-0.7mm.

4. The process for manufacturing a long stringer co-cured wall panel of claim 1, wherein, The laying angle of the third tool fabric layer is +45° or -45°; And / or, the thickness of the third tool fabric layer is 0.6mm-0.7mm.

5. The process for manufacturing a long stringer co-cured wall panel of claim 1, wherein, The laying angle of the fourth tool fabric layer is 0°, +90° or -90°; And / or, the thickness of the fourth tool fabric layer is 0.2mm-0.3mm.

6. The process for manufacturing a long stringer co-cured wall panel according to any one of claims 1 to 5, wherein The preparation method of the pneumatic aerodynamic composite cover plate comprises the following steps: S1: Brush the cover plate forming tool with a release agent, and after the release agent is completely dried, lay a layer of first tool fabric prepreg on the surface of the cover plate forming tool, and then pre-compact to obtain a first pre-compact tool fabric; S2: Lay a second tool fabric prepreg on the first pre-compact tool fabric provided in step S1, and then pre-compact after laying to obtain a second pre-compact tool fabric; S3: Laying the third tool fabric prepreg on the second pre-compacted tool fabric provided in step S2, and pre-compacting after the laying to obtain a third pre-compacted tool fabric; S4: Laying the fourth tool fabric prepreg on the third pre-compacted tool fabric provided in step S3, and pre-compacting after the laying to obtain a fourth pre-compacted tool fabric; S5: Placing the pre-compacted tool fabrics into a vacuum bag for sealing; S6: Pre-solidifying first, and then removing the bag and the mold after the pre-solidification, and then post-solidifying to obtain the aerodynamic surface composite cover plate.

7. The process for manufacturing a long stringer co-cured wall panel of claim 6, wherein, In step S1, the pre-compacting time is not less than 15 minutes, and the pre-compacting vacuum degree is less than -80 KPa; In step S1, the resin content in the first tool fabric prepreg is 45% to 50%; In step S1, the layer angle of the first tool fabric prepreg is 0°, +90° or -90°; In step S2, the pre-compacting time is not less than 15 minutes, and the pre-compacting vacuum degree is less than -80 KPa; In step S2, the resin content in the second tool fabric prepreg is 35% to 40%; In step S2, the layer angle of the second tool fabric prepreg is +45° or -45°; In step S3, the pre-compacting time is not less than 15 minutes, and the pre-compacting vacuum degree is less than -80 KPa; In step S3, the resin content in the third tool fabric prepreg is 35% to 40%; In step S3, the layer angle of the third tool fabric prepreg is +45° or -45°; In step S4, the pre-compacting time is not less than 15 minutes, and the pre-compacting vacuum degree is less than -80 KPa; In step S4, the resin content in the fourth tool fabric prepreg is 45% to 50%; In step S4, the layer angle of the fourth tool fabric prepreg is 0°, +90° or -90°.

8. The process for manufacturing a long stringer co-cured wall panel of claim 6, wherein, In step S6, the pre-solidification pressure is 0.4 Mpa to 0.7 Mpa, the vacuum is drawn during the solidification, the temperature is raised to 60°C to 63°C at a rate of 0.5°C / min to 1.0°C / min, and the temperature is kept for 16 to 17 hours; In step S6, the pre-solidification pressure is 0.4 Mpa to 0.7 Mpa, the vacuum is drawn during the solidification, the temperature is raised to 60°C to 63°C at a rate of 0.5°C / min to 1.0°C / min, and the temperature is kept for 16 to 17 hours;

Images