A processing technology of stiffened co-cured wallboard with hat stringer and hard cover plate at stringer end

Abstract

The present application relates to long string reinforced co-cured wallboard preparation technical field, especially in kind of long string end hard cover plate and the processing technology of cap-shaped long string reinforced co-cured wallboard.The long string end hard cover plate includes rubber core moulding portion, the rubber core moulding portion includes connected first and second bonding parts, the rubber core moulding portion both sides are also respectively provided with retaining portion, each retaining portion is respectively provided with retaining hole;Each retaining portion and the rubber core moulding portion are connected through cover plate R area;The thickness of the first bonding part is equal;The thickness of the second bonding part gradually decreases.The long string end hard cover plate of the present application, the long string end skin and the cap bottom area surface quality are good, the thickness is uniform, the forming quality is stable and reliable by assembling the long string end hard cover plate of the long string end, and the long string end hard cover plate is also applicable to the forming of the co-cured reinforced wallboard of multi-reinforced structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of long string reinforced co-cured wallboard preparation, in particular to a long string end hard cover plate and a processing technology of a cap-shaped long string reinforced co-cured wallboard. 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 hat-shaped structures. 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 long strings on the skin, and the skin is generally wider and longer than the long string, which is used for assembly with other parts, so the edge of the long string in the length direction has a skin.

[0003] In the development process of the cap-shaped long string reinforced wallboard, the quality of the skin inner surface of the long string end is poor, and there are problems such as fiber wrinkles and unqualified thickness. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a long string end hard cover plate to solve the problems in the prior art.

[0005] To achieve the above-mentioned purposes and other related purposes, the present application provides a long string end hard cover plate, which comprises a rubber core mold bonding part, the rubber core mold bonding part comprises a connected first bonding part and a second bonding part, and the two sides of the rubber core mold bonding part are respectively provided with a retaining part, and each retaining part is respectively provided with a retaining hole; each retaining part and the rubber core mold bonding part are connected through a cover plate R area; the thickness of the first bonding part is equal; and the thickness of the second bonding part gradually decreases.

[0006] In some embodiments of the present application, the thickness of the second bonding part gradually decreases in the direction away from the first bonding part, the angle a of the tip part of the second bonding part is 5°-30°, and the end of the sharp corner part is a boss.

[0007] In some embodiments of the present application, the thickness of the retaining part is greater than the thickness of the rubber core mold bonding part.

[0008] In some embodiments of the present application, the thickness of the first bonding part is 1mm-5mm.

[0009] In some embodiments of the present application, the thickness of the retaining portion is 3-8 mm.

[0010] In some embodiments of the present application, the material of the hard cap plate at the end of the stringer is selected from a material with a similar thermal expansion coefficient to that of the stringer.

[0011] In some embodiments of the present application, the thermal expansion coefficient of the stringer is 0.5*10 -6 / ℃-1.5*10 -6 / ℃.

[0012] In some embodiments of the present application, the material of the hard cap plate at the end of the stringer is metal; preferably, the material of the hard cap plate at the end of the stringer is steel, more preferably Invar steel.

[0013] In some embodiments of the present application, the thermal expansion coefficient of the hard cap plate at the end of the stringer is 0.5*10 -6 / ℃-2*10 -6 / ℃.

[0014] In another aspect of the present application, the use of the hard cap plate at the end of the stringer in the preparation of the hat-shaped stringer-stiffened co-cured wall panel is provided.

[0015] In another aspect of the present application, a processing technology for a hat-shaped stringer-stiffened co-cured wall panel is provided, characterized in that it comprises the following steps:

[0016] 1) Assembling the inner core mold and the flexible rubber core mold to obtain an inner core mold and flexible rubber core mold assembly;

[0017] 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;

[0018] 3) Placing the inner core mold and flexible rubber core mold assembly of step 1) into the inner cavity of the net size stringer;

[0019] 4) Using laser projection positioning to fill the remaining gaps in the inner cavity of the stringer with twist strips, and setting a temporary vacuum bag on the outer surface of the stringer and compacting it; after assembly, the cap bottom of the rubber core mold, the twist strips, the stringer edge strips, and the skin laying area of the negative mold forming tool are flush;

[0020] 5) The end of the net size stringer is provided with the hard cap plate at the end of the stringer as described above; the negative mold forming tool is provided with a cap plate groove matched with the hard cap plate at the end of the stringer; the hard cap plate at the end of the stringer is arranged in the cap plate groove; the second fitting portion of the hard cap plate at the end of the stringer is a bevel, which is fitted with the rubber core mold.

[0021] 6) The skin is laid on the skin laying area of the female die forming tool, the stringer area of the longeron, and the cap bottom area of the flexible rubber core mold, and the skin is formed after the laying is completed, and the inner core mold is taken out;

[0022] 7) The pneumatic shape surface cover plate is fixed on the outer surface of the skin, the pneumatic shape surface vacuum bag is arranged on the pneumatic shape surface cover plate, the pneumatic shape surface vacuum bag is sealed with the pneumatic shape surface cover plate through the first sealing rubber strip, and the tubular vacuum bag is communicated with the pneumatic shape surface vacuum bag;

[0023] 8) The mold is demolded after curing.

[0024] In some embodiments of the present application, the slope of the longeron stringer is 40°-50°.

[0025] In some embodiments of the present application, the angle β between the cross section of the longeron end head and the extension direction of the longeron cap top is a right angle.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] The longeron end head hard cover plate provided by the present application can ensure that the surface quality of the longeron end head skin and cap bottom area is good, the thickness is uniform, the forming quality is stable and reliable, and the longeron end head hard cover plate is also suitable for the forming of multi-stringer structure co-cured stiffened wall panels. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram of the three-dimensional structure of the longeron end head hard cover plate provided by the present application.

[0029] Figure 2 is a schematic diagram of the cross-sectional structure of the rubber core mold adhesion part in the longeron end head hard cover plate provided by the present application.

[0030] Figure 3 is Figure 2 a schematic diagram of the local enlarged structure.

[0031] Figure 4 is a schematic diagram of the front view structure of the longeron end head hard cover plate provided by the present application.

[0032] Figure 5 is a schematic diagram of the structure of the longeron end head cover plate and tooling provided by the present application.

[0033] Figure 6 is a schematic diagram of the cooperation of the longeron end head hard cover plate and the rubber core mold provided by the present application.

[0034] Figure 7 is a longeron structure diagram provided by the present application.

[0035] Figure 8It is a schematic diagram of the skin hat-shaped stringer end region wrinkle problem to be solved by the present application.

[0036] Figure 9 It is a hat-shaped stringer stiffened co-cured wallboard cross-sectional view mentioned in the present application.

[0037] Figure 10 It is a schematic diagram of the female die forming tool provided by the present application.

[0038] Figure 11 It is a schematic diagram of the final bag provided by the present application.

[0039] Figure 12 It is a physical diagram of the hat-shaped stringer stiffened co-cured wallboard stringer end skin prepared by the method of example 1 of the present application.

[0040] Figure 13 It is a physical diagram of the hat-shaped stringer stiffened co-cured wallboard stringer end skin prepared by the method of comparative example 1.

[0041] Figure 14 It is a physical diagram of the hat-shaped stringer stiffened co-cured wallboard stringer end skin prepared by the method of comparative example 2.

[0042] Figure 15 It is a thickness measurement result diagram of the hat-shaped stringer stiffened co-cured wallboard stringer end prepared by example 1.

[0043] Figure 16 It is a schematic diagram of the wallboard thickness measurement point prepared by example 1.

[0044] Figure 17 It is a wallboard ultrasonic detection result diagram prepared by example 1.

[0045] Figure 18 It is a schematic diagram of the wallboard aerodynamic shape surface test point layout after the hat-shaped stringer stiffened co-cured wallboard is prepared.

[0046] Figure 19 It is a physical diagram of the sandbag placement of the aerodynamic shape detection of the wallboard prepared by example 1.

[0047] Figure 20 It is a numerical scatter plot of the aerodynamic shape contour detection of section 2 to section 6.

[0048] Figure 21 It is a mark diagram of the stringer end wrinkle prone position of example 1.

[0049] Figure 22 It is a micro-observation skin state diagram after the stringer end wrinkle prone position of example 1 is marked and sectioned.

[0050] BRIEF DESCRIPTION OF DRAWINGS: 1 - female tool hat top area, 2 - female tool hat stringer top R angle area, 3 - female tool hat waist area, 4 - female tool stringer edge area, 5 - skin laying area, 6 - cover plate groove, 7 - forming tool stringer outer rubber core mold groove, 8 - forming tool sealant strip area groove, 9 - stringer end hard cover plate, 91 - rubber core mold fitting part, 911 - first fitting part, 912 - second fitting part, 9121 - boss, 92 - retaining part, 93 - cover plate R area, 94 - retaining hole, 10 - female forming tool, 11 - stringer hat top, 12 - stringer hat waist, 13 - stringer edge, 14 - skin, 15 - twist strip, 16 - flexible rubber core mold, 17 - pneumatic profile cover plate, 18 - first sealant strip, 19 - tubular vacuum bag, 20 - pneumatic profile vacuum bag, 21 - forming tool stringer bevel area, 22 - skin hat stringer end area DETAILED DESCRIPTION

[0051] In the description of the present application, it should be noted that the structure, proportion, size, etc. shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and do not have technical significance to limit the implementation conditions of the present application. Any modification of structure, change of proportion relationship or adjustment of size, which does not affect the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the devices or elements indicated to have a specific orientation, to be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation of the present application. In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0052] In the description of the present application, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] In addition, in the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0054] See Figure 8 In existing technologies, wrinkles often appear in the end area of ​​the cap-shaped stringer. Through extensive experimentation, this invention unexpectedly discovered a rigid end cap plate for the stringer. When applied to the processing of cap-shaped stringer reinforced co-cured wall panels, the surface quality of the stringer end skin 14 and the cap bottom area is excellent, the thickness is uniform, and the molding quality is stable and reliable. Furthermore, this end cap plate is also suitable for molding multi-ribbed co-cured reinforced wall panels. Based on this, this application was completed.

[0055] In one aspect, this invention provides a rigid end cap for a stringer, such as... Figures 1-4 The rigid end cap 9 of the stringer includes a rubber core mold fitting portion 91, which includes a first fitting portion 911 and a second fitting portion 912 connected together. Retention portions 92 are respectively provided on both sides of the rubber core mold fitting portion, and each retention portion has a retention hole 94. Each retention portion 92 is connected to the rubber core mold fitting portion 91 through a cap plate R region 93. The first fitting portion 911 has a uniform thickness; the thickness of the second fitting portion 912 gradually decreases. In application, such as... Figure 6 The thickness of the second mating part 912 of the rigid cover plate 9 at the end of the stringer gradually decreases towards the stringer direction, and the mating end with the stringer has a wedge-shaped structure. This structure can ensure that there are no fiber wrinkles in the inner cavity of the stringer when it is mated with the rubber core mold.

[0056] In the rigid end cap plate of the stringer provided by the present invention, the thickness of the second fitting portion 912 gradually decreases in the direction away from the first fitting portion 911, and the angle α of the tip of the second fitting portion 912 is 5° to 60°. In some embodiments, the angle α is 5° to 30°, 5° to 10°, 10° to 15°, 15° to 20°, 20° to 25°, or 25° to 30°, etc. The end of the pointed corner is a boss 9121 to prevent scratches during use. The boss 9121 refers to the longitudinal section of the end of the pointed corner being rectangular. The height of the boss 9121 can be, for example, 0 to 1 mm, preferably 0 to 0.3 mm, or 0.3 mm to 1 mm. More preferably, it is 0.3 mm.

[0057] In the rigid end cap plate of the stringer provided by the present invention, the thickness of the retaining portion is greater than the thickness of the rubber core mold bonding portion. In some embodiments, the thickness of the first bonding portion 911 can be, for example, 1mm-5mm, 1mm-2mm, 2mm-4mm, or 4mm-5mm, etc. The thickness of the first bonding portion 911 is preferably 2mm. The thickness of the retaining portion 92 can be, for example, 3mm-5mm, or 5mm-8mm. The thickness of the retaining portion 92 is preferably 5mm.

[0058] The long string end hard cover plate provided by the present application, the material of the long string end hard cover plate 9 is selected from materials with similar thermal expansion coefficients to the long string. In some embodiments, the thermal expansion coefficient of the long string can be 0.5×10 -6 / ℃~1.5×10 -6 / ℃, 0.5×10 -6 / ℃~1.0×10 -6 / ℃, 1.0×10 -6 / ℃~1.5×10 -6 / ℃, etc. In this way, the surface of the long string end hard cover plate 9 in contact with the skin 14 can ensure the surface quality of the long string end skin 14.

[0059] The long string end hard cover plate provided by the present application, the material of the long string end hard cover plate 9 is selected from materials with similar thermal expansion coefficients to the long string. In some embodiments, the thermal expansion coefficient of the long string can be 0.5×10 -6 / ℃~2×10 -6 / ℃, 0.5×10 -6 / ℃~1.0×10 -6 / ℃, 1.0×10 -6 / ℃~1.5×10 -6 / ℃, or 1.5×10 -6 / ℃~2×10 -6 / ℃, etc.

[0060] The present application also provides a method for preparing a long string end hard cover plate, which comprises processing the material mentioned in the first aspect of the present application into the shape of the long string end hard cover plate 9. The processing method belongs to the prior art.

[0061] Another aspect of the present application provides the use of the long string end hard cover plate as described in the present application in the preparation of a hat-shaped long string reinforced co-cured wall panel.

[0062] The present application also provides a processing technology for a hat-shaped long string reinforced co-cured wall panel, which comprises the following steps:

[0063] 1) Assemble the inner core mold and the flexible rubber core mold 16 to obtain an inner core mold and flexible rubber core mold assembly;

[0064] 2) Turn the net size long string into the negative mold forming tool 10; the net size long string includes a long string hat top 11, two symmetrically distributed long string hat waists 12, and two symmetrically distributed long string edge strips 13;

[0065] 3) Place the inner core mold and flexible rubber core mold 16 assembly of step 1) into the inner cavity of the net size long string;

[0066] 4) Using laser projection positioning, fill the remaining gap of the long string 15 filling the inner cavity of the long string, set the temporary vacuum bag on the outer surface of the long string and compact, 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 negative mold forming tool 10 are flush;

[0067] 5) The end of the net size long string is provided with a long string end hard cover plate 9 as described in the first aspect of the application; the negative mold forming tool 10 is provided with a cover plate groove 6 matched with the long string end hard cover plate 9; the long string end hard cover plate 9 is arranged in the cover plate groove 6; the second fitting part 912 of the long string end hard cover plate 9 is a bevel, which is fitted with the rubber core mold.

[0068] 6) The skin 14 is laid on the skin laying area 5 of the negative 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 is taken out;

[0069] 7) The pneumatic contour cover plate 17 is fixed on the outer surface of the skin 14, the pneumatic contour cover plate 17 is provided with a pneumatic contour vacuum bag 20, the pneumatic contour vacuum bag 20 is sealed with the pneumatic contour cover plate 17 through the first sealing rubber strip 18, and the tubular vacuum bag 19 is communicated with the pneumatic contour vacuum bag 20;

[0070] 8) Demolding after curing.

[0071] In the processing technology of the hat-shaped long string reinforced co-cured wallboard provided by the application, step 1) is to assemble the inner core mold and the flexible rubber core mold 16 to obtain the inner core mold and the flexible rubber core mold and the flexible rubber core mold assembly. The preparation method of the flexible rubber inner core mold and the flexible rubber core mold assembly comprises the following steps: placing the inner core mold in the tubular vacuum bag 19; placing the tubular vacuum bag 19 in the rubber inner cavity of the flexible rubber core mold 16 to obtain the inner core mold and the flexible rubber core mold assembly, as shown in Figure 11 .

[0072] In the preparation method of the inner core mold and the flexible rubber core mold assembly provided by the application, the inner core mold is prepared by pouring the mixed liquid rubber according to the proportioning requirements into the inner core mold forming tool, and metal chains are added in the liquid rubber to enhance the rigidity of the inner core mold.

[0073] In the processing technology of the hat-shaped long string reinforced co-cured wallboard provided by the application, step 2) is to turn the net size long string into the negative 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 9, the net size stringer includes a stringer cap top 11, two symmetrically distributed stringer cap waists 12 and two symmetrically distributed stringer edge strips 13. The two stringer cap waists 12 are respectively connected with the two side edges of the stringer cap top 11. The stringer edge strips 13 are connected with the stringer cap waists 12, so as to form a stringer with a cap-shaped cross section. Specifically, the stringer cap top 11 and the two stringer cap waists 12 enclose to form an inner cavity of the stringer. As shown in Figure 10 , the female die forming tool 10 includes a female die tool cap top area 1, two female die tool stringer cap top R angle areas 2, two female die tool cap waist areas and two female die tool edge strip areas, the two female die tool cap waist areas are respectively connected with the female die tool cap top area 1 through the two female die tool stringer cap top R angle areas 2, and enclose to form a stringer accommodating cavity. It also includes a forming tool stringer outer rubber core mold groove 7 and a forming tool sealant strip area groove 8. Among them, the stringer cap top 11 is aligned with the female die tool cap top area 1, the stringer cap waist 12 is aligned with the female die tool cap waist area 3, and the stringer edge strip 13 is aligned with the female die tool edge strip area 4, which can ensure the accurate assembly position of the stringer.

[0074] Further, as shown in Figure 7 , the slope of the stringer edge strip 13 can be 40°-50°, 40°-45°, or 45°-50°, etc. The angle β between the cross section of the stringer end and the extension direction of the stringer cap top 11 is a right angle. This design can ensure that there is no mold sticking problem during the stringer demolding process.

[0075] In the processing technology of the cap-shaped stringer reinforced 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 stringer. Among them, 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. 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 stringer by using the forming tool stringer outer rubber core mold groove 7.

[0076] In the processing technology of the cap-shaped stringer reinforced co-cured wallboard provided by the application, as shown in Figure 11 , step 4) is to fill the remaining gaps in the inner cavity of the stringer with the twist strip 15 by using laser projection positioning, seal the temporary vacuum bag, press the stringer and compact it, and ensure that the flexible rubber core mold 16 and the inner cavity of the stringer are well matched. After assembly, the bottom of the rubber core mold, the twist strip 15, the stringer edge strip 13, and the skin laying area 5 of the female die forming tool 10 are flush.

[0077] In the processing technology of the cap-shaped stringer reinforced co-cured wallboard provided by the application, as shown in Figure 5, step 5) is that the end of the net size long string is provided with the long string end hard cover plate 9 of the first aspect of the application. The long string end hard cover plate 9 may, for example, be a metal cover plate, and the material of the metal cover plate should be selected to be close to the thermal expansion coefficient of the hat-shaped long string reinforced co-cured wallboard material. 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 long string end hard cover plate 9; the long string end hard cover plate 9 is arranged in the cover plate groove 6, and the second fitting part of the long string end hard cover plate 9 is a bevel matched with the rubber core mold.

[0078] In the processing technology of the hat-shaped long string reinforced co-cured wallboard provided by the application, step 6) is to lay the skin 14 on the skin laying area 5 of the female die forming tool 10, the long string edge strip 13 area, and the hat 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 is taken out. For example, the laying of the skin 14 can be carried out on an automatic fiber laying machine. The laying angle is according to the angle specified in the drawing, for example, it can be [-45° / 45° / 45° / 90° / -45° / 0° / -45° / 90° / 45° / 45° / -45°]. The laying gap should meet the design drawing requirements. For example, the laying gap can be ≤1mm.

[0079] In the processing technology of the hat-shaped long string reinforced co-cured wallboard provided by the application, step 7) is to fix the aerodynamic surface cover plate 17 on the outer surface of the skin 14. For example, the fixed way can be pin positioning assembly. The aerodynamic surface vacuum bag 20 is sealed with the aerodynamic surface cover plate 17 through the first sealing rubber strip 18, specifically, the first sealing rubber strip 18 is pasted in the tool sealing bag area. The aerodynamic surface cover plate 17 is provided with the aerodynamic surface vacuum bag 20, and the tubular vacuum bag 19 is communicated with the aerodynamic surface vacuum bag 20. 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.

[0080] Further, the aerodynamic surface cover plate 17 can be prepared by the following method:

[0081] 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, and after the laying of the layer of prepreg is completed, a temporary vacuum bag is sealed for pre-compaction, and the compaction time is not less than 15min, and the compaction vacuum degree is lower than -80KPa;

[0082] 2. Lay up the second layer and the third layer as the tooling fabric prepreg with the resin content of 38%, and the lay-up angle is 45°. The nominal thickness of the tooling fabric prepreg is 0.65 mm. Note that air guiding should be paid attention to during the lay-up process. Each layer should be pre-compacted once after being laid up, and the compaction time is not less than 15 min, and the compaction vacuum degree is less than -80 KPa.

[0083] 3. Lay up the fourth layer as the tooling fabric prepreg with the resin content of 45%, and the lay-up angle is 0°. The nominal thickness of the tooling fabric prepreg is 0.23 mm. After the fourth layer is laid up, a temporary vacuum bag is sealed for pre-compaction, and the compaction time is not less than 15 min, and the compaction vacuum degree is less than -80 KPa.

[0084] 4. Seal the final vacuum bag. Note that air guiding should be paid attention to during the sealing process. Air guiding filaments are placed in the remaining area of the part, and the air guiding filaments contact the edge air guiding fibers. The surface can be selected from 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. It is recommended to use a porous release film for large-sized parts.

[0085] 5. Curing. The curing of the cover plate is a two-step curing process, including pre-curing and post-curing. The pre-curing pressure is 0.6 MPa. The whole process is vacuumized during the curing process. The temperature is raised to 60°C at a rate of 0.5°C / min, and the temperature is maintained for 16 hours.

[0086] 6. After the pre-curing is completed, the bag is removed, and the positioning holes are drilled using a drill jig. After drilling, the mold is removed.

[0087] 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°C at a rate of 1.5°C / min, then the temperature is raised to 200°C at a rate of 0.5°C / min and maintained for 15 min. The temperature is lowered to 190°C at a rate of 1.5°C / min and maintained for 8 hours. The temperature is lowered to 60°C at a rate of 1.5°C / min, and the curing is completed.

[0088] In the processing technology of the hat-shaped stringer reinforced co-cured wall panel provided by the application, step 8) is curing and demolding. Specifically, in the curing and demolding step, the hard cover plate 9 at the end of the stringer and the pneumatic outer shape 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, then the flexible rubber core mold 16 is pulled out from the inner cavity of the stringer in a manual dragging manner, and the second auxiliary material is taken out after the flexible rubber core mold 16 is pulled out.

[0089] In step 8) of the application, specifically, the first auxiliary material includes the pneumatic outer shape vacuum bag 20 and the first sealing rubber strip 18.

[0090] 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 including a tubular vacuum bag 19 and the like, and 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 rotating multiple times, and then the auxiliary material is taken out by a method of pulling.

[0091] 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 sealing rubber strip and a vacuum bag, sealing the other end of the flexible rubber core mold 16 with a third sealing rubber 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, and then manually pulling the flexible rubber core mold 16 out of the inner cavity of the longeron, and taking out the third auxiliary material from both ends after the flexible rubber core mold 16 is taken out. The third auxiliary material includes the second sealing rubber strip, the third sealing rubber strip, the vacuum bag, the vacuum bag air-permeable sealing bag, and the like.

[0092] The beneficial effects of the present application are further illustrated in the following examples.

[0093] 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 in 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.

[0094] 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 substantial change of the technical content, is also regarded as the scope of implementation of the present application.

[0095] In the following examples, the reagents, materials and instruments used are commercially available unless otherwise specified.

[0096] Example 1

[0097] Processing technology of hat-shaped stringer reinforced co-cured wallboard

[0098] 1. Place the inner core mold in the tubular vacuum bag 19; place the tubular vacuum bag 19 in the rubber inner cavity of the flexible rubber core mold 16 to obtain an inner core mold and flexible rubber core mold assembly ready for use;

[0099] 2. Complete the manufacturing of the aerodynamic surface composite cover plate of the hat-shaped stringer reinforced co-cured wallboard; the aerodynamic surface composite cover plate can be purchased and prepared by using the preparation method of the aerodynamic surface composite cover plate in the embodiment of the present application.

[0100] 3. Prepare the net size stringer by hand laying and ultrasonic automatic cutting, and turn the net size stringer to the negative mold forming tool 10, pay attention to align the stringer cap top 11 with the negative mold tool cap top area 1, align the stringer cap waist with the negative mold tool cap waist area 3, and align the stringer edge strip 13 with the negative mold tool edge strip area 4, which can ensure the accurate assembly position of the stringer;

[0101] 4. Assemble the inner core mold and the tubular vacuum bag 19 into the flexible rubber core mold inner cavity, and place the flexible rubber core mold into the inner cavity of the stringer by positioning with the forming tool stringer outer rubber core mold groove 7;

[0102] 5. Assemble the twist strip 15 into the inner cavity of the stringer by laser projection positioning, seal the temporary vacuum bag and compact it, ensure that the rubber core mold and the inner cavity of the stringer are matched perfectly, and ensure that the cap bottom part of the rubber core mold is flush with the plane of the twist strip 15 and the twist of the stringer edge strip part and the skin laying area 5 of the forming negative mold tool after assembly is completed;

[0103] 6. Assemble the stringer end hard cover plate 9 in the groove of the stringer end negative mold forming tool 10, and the stringer end hard cover plate 9 and the rubber core mold present a wedge-shaped fit, as shown in Figure 6 .

[0104] 7. Lay the skin 14 on the skin area of the assembled negative mold forming tool 10, the stringer edge strip area, and the cap bottom area of the rubber core mold by using the automatic fiber laying machine, the laying angle is according to the angle specified in the drawing, and the laying gap should meet the requirements of the design drawing, after the laying is completed, the skin 14 is formed, and after the skin laying is completed, the inner core mold is taken out.

[0105] 8. Assemble the aerodynamic surface stringer end hard cover plate 9 on the outer surface of the skin 14 by using the pin positioning, paste the first sealing rubber strip 18 in the tool bag sealing area, connect the rubber core mold internal tubular vacuum bag 19 with the aerodynamic surface vacuum bag 20, and ensure that the rubber core mold inner cavity and the curing pressure outside the external vacuum bag are the same during the curing process.

[0106] 9. After curing, demold the rigid end cover plate 9 and the pneumatic outer surface cover plate 17 of the stringer respectively. Remove the first auxiliary material from the inner cavity of the flexible rubber core mold 16. Vacuum seal both ends of the flexible rubber core mold 16. Deform the flexible rubber core mold 16 by drawing a vacuum. Then, manually drag the flexible rubber core mold 16 out of the inner cavity of the stringer. After the flexible rubber core mold 16 is removed, take out the second auxiliary material.

[0107] Comparative Example 1

[0108] The other steps are the same as in Example 1, except that the rigid end cap 9 of the stringer in step 6 is not present.

[0109] Comparative Example 2

[0110] The end-mold forming fixture 10 for the stringer does not have a cover plate groove 6. Instead, a thin gasket of soft material with a thickness of 0.15-0.6 mm is placed at the end of the stringer. The soft material is carbon fiber fabric. The remaining steps are the same as in Example 1.

[0111] Test results:

[0112] 1. Appearance inspection

[0113] 1.1 Using the scheme of Example 1, the rigid cap plate scheme for the stringer end is used to manufacture the hat-shaped stringer stiffened wall panel. The surface quality of the stringer end skin is good, without defects such as wrinkles or pits, and the appearance inspection is qualified. Figure 12 .

[0114] 1.2 Using the scheme in Comparative Example 1, without a rigid end cap for the stringer, wrinkles will form at the stringer ends, resulting in failure to pass visual inspection. For example... Figure 13 .

[0115] 1.3 The scheme adopted in Comparative Example 2 has a thin gasket made of soft material at the end and a polytetrafluoroethylene false twist strip. The end of the long stringer of the female mold tooling does not have a cover plate groove 6, such as Figure 14 After the solution was solidified, pits appeared at the ends of the stringer, with some pits having a depth of >1mm, which failed the appearance inspection.

[0116] 2. Thickness Measurement

[0117] 2.1 Measurement of the thickness of the stringer end

[0118] The specification requires a nominal thickness of 2.057 mm for the girder end, with a range of 1.954 mm to 2.160 mm. From... Figure 15 The thickness test data distribution chart shows that the thickness values ​​of M1~M5 and N1~N5 are all within the range of 1.954mm~2.160mm. Therefore, the use of the stringer end cover plate mentioned in this patent can ensure that the stringer end thickness is qualified.

[0119] 2.2 Measure the thickness of the wallboard by using magnetic thickness gauge (one point calibration). The wallboard is spaced 250 mm along the heading, and the thickness is measured at Figure 16 Thirteen thickness measurement points are arranged.

[0120] ① Non-cured region of the skin

[0121] The nominal thickness of the non-cured region of the skin is 2.057 mm; the tolerance is ±5%; and the single value acceptance value is 1.954-2.159 mm. The thickness of the non-cured region of the skin meets the requirements.

[0122] Table 1 Thickness of the non-cured region of the skin

[0123]

[0124] ② Cured region

[0125] The nominal thickness of the cured region is 3.740 mm; the tolerance is ±5%; and the single value acceptance value is 3.553-3.927 mm. The thickness of the cured region meets the requirements.

[0126] Table 2 Thickness of the cured region

[0127]

[0128] The hat stringer reinforced wallboard is manufactured by using the example 1, and the thickness of the skin region and the cured region is detected by using the magnetic thickness gauge. The detection results are qualified.

[0129] ③ Stringer plane region

[0130] The nominal thickness of the stringer plane region is 1.683 mm; the tolerance is ±8% mm; and the single value acceptance value is 1.548-1.817 mm. The thickness of the stringer plane region meets the requirements.

[0131] Table 3 Thickness of the stringer plane region

[0132]

[0133] ④ Stringer hat waist R region

[0134] The nominal thickness of the stringer hat waist R region 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 thickness of the stringer hat waist R region meets the requirements.

[0135] Table 4 Thickness of the stringer hat waist R region

[0136]

[0137] The thickness of the long string plane area and the R area is detected by the magnetic thickness gauge, and the thickness of the long string plane area and the R area is qualified.

[0138] 3. Ultrasonic testing

[0139] From the C-scan detection image, it can be seen that the preset artificial defects are normally detected, and the size deviation meets the standard requirement (Area ± 25%), which indicates that the detection sensitivity and the evaluation threshold setting are reasonable.

[0140] Macroscopic defects: No macroscopic defects are found in the detection area.

[0141] Porosity: No area with excessive porosity is found.

[0142] In summary, from the above, Figure 17 The ultrasonic detection image shows that the nondestructive testing is qualified.

[0143] 4. Shape measurement

[0144] After the wallboard is cut, the film detection is used to detect the aerodynamic surface shape; along the heading, 5 detection sections (section 2-section 6) are arranged at intervals of 250 mm, and 8 film detection points are arranged for each section. The wallboard aerodynamic surface film detection point layout diagram is as shown in Figure 18 , the wallboard aerodynamic surface detection sandbag placement physical diagram is as shown in Figure 19 , and the aerodynamic surface profile detection numerical scatter diagram of section 2-section 6 is as shown in FIG. 20. The aerodynamic surface of the part is detected by the film detection method, and the specification requires that the aerodynamic surface profile is ≤0.75 mm, Figure 20 The aerodynamic surface profile detection values of section 2-section 6 are less than 0.75 mm, Figure 20 The detection data shows that the profile values of section 2-section 6 are less than 0.75 mm, so the wallboard aerodynamic surface is qualified.

[0145] 5. The part prepared in Example 1 is cut at the position where wrinkles are prone to occur at the end of the long string, as shown in Figure 21 The horizontal line area, the Olympus DSX1000 microscope is used to observe the skin state of the end of the long string, and it can be seen from Figure 22 that the skin fiber thickness in this area is uniform.

[0146] The above examples are only illustrative of 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 made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.

Claims

1. A processing technology for a hat-shaped stringer reinforced co-cured wall panel, characterized in that, Includes the following steps: 1) The inner core mold and the flexible rubber core mold are assembled to obtain the inner core mold and flexible rubber core mold assembly; 2) Flip the net-size stringer into the female mold forming fixture; the net-size stringer includes a stringer cap top, two symmetrically distributed stringer cap waists, and two symmetrically distributed stringer edge strips; 3) Place the inner core mold and flexible rubber core mold assembly described in step 1) into the inner cavity of the net-size stringer; 4) Using laser projection for positioning, fill the remaining gaps in the inner cavity of the stringer with the twist strip, put a temporary vacuum bag on the outer surface of the stringer and compact it, so that the bottom of the cap of the assembled rubber core mold, the twist strip, the stringer edge strip, and the skin covering area of ​​the female mold forming tool are flush. 5) The end of the net-size stringer is provided with a stringer end rigid cover plate; the female mold forming fixture is provided with a cover plate groove that matches the stringer end rigid cover plate; the stringer end rigid cover plate is placed in the cover plate groove; the second fitting part of the stringer end rigid cover plate is an inclined surface that fits with the rubber core mold; the stringer end rigid cover plate includes a rubber core mold fitting part (91), the rubber core mold fitting part includes a first fitting part (911) and a second fitting part (912) connected to each other, the rubber core mold fitting part... The two sides of the mating part are respectively provided with retaining parts (92), and each retaining part is provided with a retaining hole (94); each retaining part is connected to the rubber core mold mating part through the cover plate R area (93); the first mating part (911) has the same thickness; the thickness of the second mating part (912) gradually decreases in the direction away from the first mating part (911), and the angle α of the tip of the second mating part (912) is 5°~30°; the end of the tip is a boss (9121). 6) Perform skin fabrication in the skin-laying area, the flange area of ​​the stringer, and the cap bottom area of ​​the flexible rubber core mold of the female mold forming tooling. After the fabrication is completed, the skin is formed, and the inner core mold is removed. 7) Fix a pneumatic shape surface cover plate to the outer surface of the skin. A pneumatic shape surface vacuum bag is provided on the pneumatic shape surface cover plate. The pneumatic shape surface vacuum bag is sealed to the pneumatic shape surface cover plate by the first sealing strip, and the tubular vacuum bag is connected to the pneumatic shape surface vacuum bag. 8) Demold after curing.

2. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 1, characterized in that, The thickness of the retaining part (92) is greater than the thickness of the rubber core mold bonding part (91); And / or, the thickness of the first bonding portion (911) is 1mm to 5mm; And / or, the thickness of the retaining portion (92) is 3mm to 8mm.

3. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 1, characterized in that, The rigid cover plate at the end of the stringer is made of a material with a coefficient of thermal expansion similar to that of the stringer.

4. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 3, characterized in that, The thermal expansion coefficient of the stringer is 0.5 × 10⁻⁶. -6 / ℃~1.5×10 -6 / ℃.

5. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 3, characterized in that, The rigid cover plate at the end of the stringer is made of metal. And / or, the coefficient of thermal expansion of the rigid end cap of the stringer is 0.5 × 10⁻⁶. -6 / ℃~2×10 -6 / ℃.

6. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 5, characterized in that, The rigid cover plate at the end of the stringer is made of steel.

7. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 6, characterized in that, The rigid cover plate at the end of the stringer is made of Invar steel.

8. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 1, characterized in that, The slope of the long stringer flange is 40°~50°.

9. The processing technology of the hat-shaped stringer reinforced co-cured wall panel as described in claim 1, characterized in that, The angle β between the cross section of the end of the girder and the extension direction of the girder cap is a right angle.

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