Composite material structure non-autoclave combination die forming method

Abstract

The invention belongs to the technical field of composite material manufacturing, and relates to a composite material structure non-autoclave combination die forming method which comprises the following steps: step 1, preparing a forming die; 2, auxiliary materials are prepared; step 3, blanking the composite material; step 4, paving a composite material in a non-autoclave; 5, the composite material obtained after laying is completed is subjected to mold closing and then packaged; step 6, carrying out vacuum detection on the packaged composite material; step 7, curing the composite material; according to the method, the air guide tows are arranged when the composite material is laid, the non-adhesive polytetrafluoroethylene cloth, the non-adhesive glass fiber cloth and other auxiliary materials are used when the composite material is compacted and packaged, and the air guide window is arranged in the R-angle area, so that the composite material structure manufactured through combination die non-autoclave forming effectively meets the product quality requirement. And compared with an autoclave forming process, the equipment cost and the energy power cost are effectively reduced by using the curing furnace for curing.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material manufacturing, and relates to a composite material structure non-autoclave combined mold forming method. Background Art

[0002] Composite materials have been used in aircraft structures since the early 1970s and have rapidly developed into one of the four major structural materials in aviation after aluminum, steel and titanium. The amount of composite materials used has long been an indicator of the advancement of aircraft. Composite materials have the characteristics of simultaneous material manufacturing and structural molding. The properties of the material are imparted to the structure through the manufacturing process, so the molding process of composite components is particularly important. At present, the autoclave molding process is the main method for producing high-quality composite components for aerospace. However, it has problems such as high energy consumption, high equipment manufacturing and operating costs, and high requirements for molding molds.

[0003] Compared with the autoclave molding process, the out of autoclave (OOA) molding process transfers the composite material curing site to an oven or curing furnace that is cheaper and does not require external pressure. It can effectively reduce the manufacturing cost while meeting the use requirements of the manufactured products. Therefore, more and more research is being conducted on the out of autoclave molding process.

[0004] The non-autoclave molding process has a low molding pressure (about 0.1MPa). When preparing composite materials with many R angles formed by combined molds, defects such as lack of glue, bridging, and high porosity are easily formed. Therefore, it is urgent to improve the non-autoclave combined mold molding process technology to manufacture composite materials that meet product performance requirements. Summary of the invention

[0005] Technical problem solved by the invention: The invention aims to solve the quality problems of high manufacturing cost of existing autoclave molding process and easy occurrence of glue deficiency, bridging, high porosity and other quality problems at the R corner of composite material structure molded by non-autoclave combination mold. A non-autoclave combination mold molding method for composite material structure is proposed, and the method can be applied to manufacture composite material structure that meets product performance requirements.

[0006] Technical solution of the present invention

[0007] A composite material structure non-autoclave combined mold forming method comprises the following steps:

[0008] Step 1: Preparation of molding mold;

[0009] Step 2: Preparation of auxiliary materials;

[0010] Step 3: Cutting composite materials;

[0011] Step 4: Non-autoclave composite lay-up;

[0012] Step 5: After the composite material is stacked, mold it and then package it;

[0013] Step 6: Perform vacuum testing on the packaged composite material;

[0014] Step 7: Curing the composite material.

[0015] Further, step 1 of preparing the molding mold is as follows: after cleaning the surfaces of each assembly mold of the molding mold, apply a mold release agent, the type of mold release agent is FREKOTE44NC; when a newly made or repaired molding mold is used for the first time, use a brush or soft cloth dipped in the mold release agent, and apply three thin layers of FREKOTE crosswise; when using the mold release agent again on a molding mold that has been used with the mold release agent, do not apply too much mold release agent;

[0016] The specific process of coating the release agent on the surface of the molding mold is as follows: 1) Check the area where the tape is used to isolate the putty strips to prevent the release agent from contaminating the bagging area; 2) On the mold surface, use a brush or soft cloth to dip the release agent and apply a thin cross-coat; 3) After each layer of release agent is applied, dry it at 25°C for 15 minutes; 4) After the release agent is dry, proceed with the composite material laying operation.

[0017] Furthermore, the auxiliary materials in step 2 include isolation film, high temperature resistant tape, non-adhesive polytetrafluoroethylene cloth, non-adhesive glass fiber cloth, vacuum bag, sealing strip, and paving and compacting tools; ensure that the brand and quantity of the above auxiliary materials meet the manufacturing requirements.

[0018] Furthermore, step 3 of cutting the composite material specifically includes: after the composite material is thawed in the clean room, the cutting is completed according to the composite material structure layering and size, and information is marked. The thawing time of the composite material varies with the total thickness of the composite material, and the thawing time is at least 6 hours.

[0019] Further, step 4 of non-autoclave composite material layup specifically includes the following steps:

[0020] Step 4.1 Place the molding mold on a flat workbench in a clean room with a temperature of 18°C ​​to 26°C and a relative humidity of 15% to 65%;

[0021] Step 4.2: Lay the first layer of composite material on the bottom mold of the forming mold according to the boundary and direction shown by the laser projector, and use a scraper to comb along the parallel direction of the composite material fiber or the warp direction of the fabric;

[0022] When laying composite materials, it is allowed to make cuts, overlap the cuts, overlap 15-25mm, and stagger the cuts between layers by 15-30mm;

[0023] When laying the first layer of composite material on the bottom mold of the forming mold, do not tear off the isolation film on the surface of the prepreg when laying and compacting at the R corner of the bottom mold. Use a laying and compacting tool to compact the first layer of composite material through the isolation film to protect the fiber. In addition, try to scrape and press parallel to the fiber direction of the R corner when compacting;

[0024] Step 4.3 After laying the first layer of composite material on the bottom mold of the forming mold, an air-conducting fiber bundle is arranged between the outer edge of the composite material and the bottom mold, the air-conducting fiber bundle is a dry glass fiber material, and the width of each fiber bundle is 5 mm to 10 mm; one end of the air-conducting fiber bundle is placed outside the edge line of the first layer of composite material, and the connection length with the first layer of composite material is not less than 20 mm; the other end of the air-conducting fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0025] Step 4.4: Lay a non-adhesive polytetrafluoroethylene cloth on the first layer of composite material, and open a plurality of equally spaced air guide windows at the R corners of the non-adhesive polytetrafluoroethylene cloth;

[0026] Step 4.5: insert one end of the air-conducting fiber bundle into the air-conducting window at the R corner of the adhesive-free polytetrafluoroethylene cloth, and connect it to the R corner of the first layer of composite material. The length of the other end of the air-conducting fiber bundle meets the requirements of being connected to the adhesive-free glass cloth during subsequent vacuum compaction and being connected to the breathable felt during packaging. After the air-conducting fiber bundle is drawn out, the remaining air-conducting window gap is sealed with a non-porous film or tape; vacuum compaction is performed. After the vacuum compaction is completed, the vacuum bag, vacuum nozzle, adhesive-free glass fiber cloth, adhesive-free polytetrafluoroethylene cloth and the air-conducting fiber bundle at the R corner are removed;

[0027] The specific process of vacuum compaction is as follows: lay glue-free polytetrafluoroethylene cloth on the surface of the composite material, the outer edge size D2 of the glue-free polytetrafluoroethylene cloth is larger than the outer edge size D1 of the composite material layer, and D2-D1≥10mm is satisfied; lay glue-free glass fiber cloth on the surface of the glue-free polytetrafluoroethylene cloth, the outer edge size D3>D2, and no bridging is generated during vacuuming; the glue-free glass fiber cloth is sealed with high-temperature resistant tape on all sides to ensure that the fibers do not fall off, and the air-conducting fiber bundle is connected to the glue-free glass fiber cloth; place a vacuum nozzle above the glue-free glass fiber cloth, lay a vacuum bag on the glue-free glass fiber cloth, lay a sealing strip around the molding mold, ensure that the sealing strip is tightly connected to the vacuum bag, and vacuum compact, the vacuum degree is not less than 0.09MPa, and the time is at least 15min; then remove the vacuum nozzle, remove the vacuum bag, the glue-free polytetrafluoroethylene cloth, the glue-free glass fiber cloth and the air-conducting fiber bundle at the R corner;

[0028] Step 4.6: According to the method of step 4.2, after laying 1 to 3 layers of composite materials on the bottom mold of the forming mold, arrange an air guide fiber bundle on the outer edge of the uppermost composite material, then lay a non-glue polytetrafluoroethylene cloth on the uppermost composite material, and open a plurality of equally spaced air guide windows at the R corner of the non-glue polytetrafluoroethylene cloth; according to the method of step 4.5, arrange an air guide fiber bundle at the R corner of the uppermost composite material and perform vacuum compaction and removal; one end of the air guide fiber bundle is placed outside the edge line of the uppermost composite material, and the connection length with the uppermost composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0029] Step 4.7: Repeat step 4.6 until the composite material layer on the bottom mold is completed, and the upper mold is installed on the bottom mold on which the composite material layer is laid, so as to complete the combination of the upper mold and the bottom mold;

[0030] Step 4.8: Laying the composite material layer of the upper mold in the molding mold on the bottom mold;

[0031] When laying the composite material layer of the upper mold, only remove the isolation film and isolation paper on both sides of the composite material in the overlapping area of ​​the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle around the composite material and the R corner position in the central raised area of ​​the bottom mold according to the method of steps 4.5 to 4.6, and perform vacuum compaction and removal;

[0032] Step 4.8: Repeat step 4.7 until the composite material layer on the upper mold is completed;

[0033] Step 4.9: flip and lay the composite material outside the overlapped area of ​​the upper mold and the bottom mold layer by layer onto the upper mold, lay 1 to 3 layers of composite material each time flipping, arrange the air guide fiber bundle at the outer edge of the composite material, and perform vacuum compaction and removal according to the method of step 4.5 until all composite material layers of the upper mold are flipped and laid; one end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0034] Step 4.10 Place a twist strip at the T-shaped R corner between the upper mold, the bottom mold and the peripheral mold in the forming mold;

[0035] Step 4.11 lays the composite material on the periphery of the combined mold formed by the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle on the outer edge of the outermost layer of composite material, and perform vacuum compaction and removal according to the method of step 4.5. One end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the glue-free glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging; the starting position of the layer avoids the corner of the molding mold, the starting position is 15-25 mm away from the corner, and the starting positions of each layer are staggered by 15-30 mm.

[0036] Furthermore, in step 5, the mold body closing process is: assemble the silicone soft mold with the upper mold, install the peripheral mold to the outer periphery of the upper mold and the bottom mold through connecting bolts, connect the top mold with the peripheral mold and the upper mold, and to prevent cloth jamming, the mold should be opened repeatedly for inspection to eliminate defects until the mold clearance of each mold is no more than 0.2 mm; after ensuring that there is no cloth jamming, the mold closing is completed.

[0037] Furthermore, in step 5, the specific packaging process is: laying an isolation film on the molding mold after mold closing, and the outer size of the isolation film can completely cover the molding mold; laying a breathable felt on the isolation film, and placing a vacuum nozzle on the breathable felt; laying a vacuum bag on the breathable felt, and laying a sealing strip around the flat workbench to ensure that the sealing strip is tightly connected to the vacuum bag; evacuating, and the vacuum degree is ≥0.090MPa.

[0038] Further, in step 6, when the vacuum degree in the vacuum bag reaches 0.09 MPa until the vacuum degree stabilizes, the vacuum source is disconnected or turned off after 15 minutes, and the vacuum gauge reading drops by no more than 0.017 MPa within 5 minutes.

[0039] Further, in step 7, the encapsulated molding mold is operated into the curing equipment, and the curing parameters are: the vacuum degree in the vacuum bag is not less than -0.090MPa, the room temperature is heated to 82℃±10℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 30min-60min, and the temperature is further heated to 127℃±2℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 120min; the temperature is reduced to below 60℃ at a cooling rate of ≤5℃ / min, and the product is taken out of the curing equipment; during the entire curing cycle, the pressure in the vacuum bag should be maintained at not less than -0.090MPa.

[0040] Furthermore, the method further comprises:

[0041] Step 8: Remove the vacuum nozzle on the breathable felt, remove the vacuum bag, breathable felt and non-porous isolation film; use non-metallic tools to demould and open the mold, and clean the excess materials on the surface of the molding mold;

[0042] Step 9: Check whether the formed composite material has any damage or excess;

[0043] Step 10: If there are delamination defects in the composite material after molding, use high temperature resistant paste glue and repair it according to the following scheme:

[0044] 10.1 Drill a φ2.1mm hole at the upper and lower edges of the defect;

[0045] 10.2 Inject glue into the defect from the lower hole until the glue overflows from the upper hole;

[0046] 10.3 Seal the two holes with tape;

[0047] 10.4 After the injected glue solidifies, remove the tape and grind it smooth.

[0048] Beneficial Effects

[0049] The present invention proposes a low-porosity non-autoclave molding method for composite material structures. By arranging air guide bundles when stacking composite materials, using auxiliary materials such as adhesive-free polytetrafluoroethylene cloth and adhesive-free glass fiber cloth during compaction and packaging, and setting air guide windows for R corner areas, the composite material structure manufactured by the combination mold non-autoclave molding can effectively meet product quality requirements. Using a curing furnace for curing is more effective than the autoclave molding process, which effectively reduces equipment costs and energy and power costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a flow chart of the method of the present invention;

[0051] Figure 2 This is a schematic diagram of the non-autoclave combined molding die of the present invention;

[0052] Figure 3 It is a top view of the non-autoclave combined molding die of the present invention;

[0053] Figure 4 for Figure 3 Top view along AA;

[0054] Figure 5 yes Figure 4 Middle B is a partial enlarged schematic diagram;

[0055] Among them, 01 bottom mold, 02 upper mold, 03 peripheral mold, 04 silicone soft mold, 06 connecting bolts, 07, composite material structure;

[0056] Figure 6 This is an illustration of paving and compaction at the R corner;

[0057] Among them, 08 prepreg layer, 09 isolation film, 10 laying and compacting tool, 11, R angle laying and compacting direction;

[0058] Figure 7It is a schematic diagram of the arrangement of the peripheral air-conducting fiber bundles of the composite material of the present invention;

[0059] Among them, 08 prepreg layers, 12 air-conducting fiber bundles;

[0060] Figure 8 This is a schematic diagram of the air guide window at the R corner of the composite material;

[0061] Among them, an air guide window is opened on the isolation membrane 13;

[0062] Fig. 9 Arrangement of air guide windows and air guide fiber bundles at the R corner of the composite material;

[0063] Among them, 13, an air guide window is opened on the isolation film, 12, an air guide fiber bundle, 08, a prepreg layer;

[0064] Fig.10 It is a schematic diagram of vacuum compaction;

[0065] Among them, 24 molding mold, 08 prepreg layer, 12 air guide fiber bundle, 14 non-glue polytetrafluoroethylene cloth, 15 non-glue glass fiber cloth, 16 vacuum bag, 17 sealing strip, D1 composite material layer outer edge size, D2 non-glue polytetrafluoroethylene cloth outer edge size, D3 non-glue glass fiber cloth outer edge size;

[0066] Fig.11 This is a schematic diagram of the upper mold layer of the combined mold;

[0067] Among them, 01 is the bottom mold, 02 is the upper mold, 18 is the prepreg layer of the bottom mold, and 19 is the prepreg layer of the upper mold after the bottom mold prepreg layer is copied;

[0068] Fig.12 Schematic diagram of the placement of twist strips at the T-shaped R corner of composite materials;

[0069] Among them, 01 is the bottom mold, 02 is the upper mold, 03 is the peripheral mold, 20 is the upper mold prepreg layer, 18 is the bottom mold prepreg layer, and 21 is the twist strip;

[0070] Fig.13 It is a packaging schematic diagram;

[0071] Among them, 24 forming mold, 22 combined tooling (including prepreg layer), 23 non-porous isolation film, 25 breathable felt, 16 vacuum bag, 17 sealing strip;

[0072] Fig.14 is the curing parameter curve;

[0073] Among them, section a-heating rate 10.5℃ / min, section b-holding time 145min, section c-heating rate 21.0℃ / min, section d-holding time 2120min, section e-cooling rate 5.0℃ / min;

[0074] Fig.15 Schematic diagram for repair;

[0075] Among them, 26 are defect areas, 27 are glue overflow holes, and 28 are glue injection holes. DETAILED DESCRIPTION

[0076] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0077] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0078] One embodiment of the present invention is to provide a composite material structure non-autoclave combined mold forming method, comprising the following steps:

[0079] Step 1: Preparation of the molding mold: After cleaning the surfaces of each mold assembly, apply a release agent, the type of release agent is FREKOTE44NC; when a new or repaired molding mold is used for the first time, use a brush or soft cloth dipped in the release agent, and apply three thin layers of FREKOTE crosswise; when using the release agent on a molding mold that has been used with the release agent again, do not apply too much release agent;

[0080] The specific process of coating the release agent on the surface of the molding mold is as follows: 1) Check the area where the tape is used to isolate the putty strips to prevent the release agent from contaminating the bagging area; 2) On the mold surface, use a brush or soft cloth to dip the release agent and apply a thin cross-coat; 3) After each layer of release agent is applied, dry it at 25°C for 15 minutes; 4) After the release agent is dry, proceed with the composite material laying operation.

[0081] Step 2: Preparation of auxiliary materials, including isolation film, high temperature resistant tape, non-adhesive polytetrafluoroethylene cloth, non-adhesive fiberglass cloth, vacuum bag, sealing strip, paving and compacting tools; ensure that the brand and quantity of the above auxiliary materials meet the manufacturing requirements.

[0082] Step 3: Unloading of composite materials: After the composite materials are thawed in the clean room, unloading is completed according to the composite material structure layering and size, and information is marked. The thawing time of the composite materials varies with the total thickness of the composite materials, and the thawing time is at least 6 hours.

[0083] Step 4: Non-autoclave composite lay-up;

[0084] The following steps are involved:

[0085] Step 4.1 Place the molding mold on a flat workbench in a clean room with a temperature of 18°C ​​to 26°C and a relative humidity of 15% to 65%;

[0086] Step 4.2: Lay the first layer of composite material on the bottom mold of the forming mold according to the boundary and direction shown by the laser projector, and use a scraper to comb along the parallel direction of the composite material fiber or the warp direction of the fabric;

[0087] When laying composite materials, it is allowed to make cuts, overlap the cuts, overlap 15-25mm, and stagger the cuts between layers by 15-30mm;

[0088] When laying the first layer of composite material on the bottom mold of the forming mold, do not tear off the isolation film on the surface of the prepreg when laying and compacting at the R corner of the bottom mold. Use a laying and compacting tool to compact the first layer of composite material through the isolation film to protect the fiber. In addition, try to scrape and press parallel to the fiber direction of the R corner when compacting;

[0089] Step 4.3 After laying the first layer of composite material on the bottom mold of the forming mold, an air-conducting fiber bundle is arranged between the outer edge of the composite material and the bottom mold, the air-conducting fiber bundle is a dry glass fiber material, and the width of each fiber bundle is 5 mm to 10 mm; one end of the air-conducting fiber bundle is placed outside the edge line of the first layer of composite material, and the connection length with the first layer of composite material is not less than 20 mm; the other end of the air-conducting fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0090] Step 4.4: Lay a non-adhesive polytetrafluoroethylene cloth on the first layer of composite material, and open a plurality of equally spaced air guide windows at the R corners of the non-adhesive polytetrafluoroethylene cloth;

[0091] Step 4.5: insert one end of the air-conducting fiber bundle into the air-conducting window at the R corner of the adhesive-free polytetrafluoroethylene cloth, and connect it to the R corner of the first layer of composite material. The length of the other end of the air-conducting fiber bundle meets the requirements of being connected to the adhesive-free glass cloth during subsequent vacuum compaction and being connected to the breathable felt during packaging. After the air-conducting fiber bundle is drawn out, the remaining air-conducting window gap is sealed with a non-porous film or tape; vacuum compaction is performed. After the vacuum compaction is completed, the vacuum bag, vacuum nozzle, adhesive-free glass fiber cloth, adhesive-free polytetrafluoroethylene cloth and the air-conducting fiber bundle at the R corner are removed;

[0092] The specific process of vacuum compaction is as follows: lay glue-free polytetrafluoroethylene cloth on the surface of the composite material, the outer edge size D2 of the glue-free polytetrafluoroethylene cloth is larger than the outer edge size D1 of the composite material layer, and D2-D1≥10mm is satisfied; lay glue-free glass fiber cloth on the surface of the glue-free polytetrafluoroethylene cloth, the outer edge size D3>D2, and no bridging is generated during vacuuming; the glue-free glass fiber cloth is sealed with high-temperature resistant tape on all sides to ensure that the fibers do not fall off, and the air-conducting fiber bundle is connected to the glue-free glass fiber cloth; place a vacuum nozzle above the glue-free glass fiber cloth, lay a vacuum bag on the glue-free glass fiber cloth, lay a sealing strip around the molding mold, ensure that the sealing strip is tightly connected to the vacuum bag, and vacuum compact, the vacuum degree is not less than 0.09MPa, and the time is at least 15min; then remove the vacuum nozzle, remove the vacuum bag, the glue-free polytetrafluoroethylene cloth, the glue-free glass fiber cloth and the air-conducting fiber bundle at the R corner;

[0093] Step 4.6: According to the method of step 4.2, after laying 1 to 3 layers of composite materials on the bottom mold of the forming mold, arrange an air guide fiber bundle on the outer edge of the uppermost composite material, then lay a non-glue polytetrafluoroethylene cloth on the uppermost composite material, and open a plurality of equally spaced air guide windows at the R corner of the non-glue polytetrafluoroethylene cloth; according to the method of step 4.5, arrange an air guide fiber bundle at the R corner of the uppermost composite material and perform vacuum compaction and removal; one end of the air guide fiber bundle is placed outside the edge line of the uppermost composite material, and the connection length with the uppermost composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0094] Step 4.7: Repeat step 4.6 until the composite material layer on the bottom mold is completed, and the upper mold is installed on the bottom mold on which the composite material layer is laid, so as to complete the combination of the upper mold and the bottom mold;

[0095] Step 4.8: Laying the composite material layer of the upper mold in the molding mold on the bottom mold;

[0096] When laying the composite material layer of the upper mold, only remove the isolation film and isolation paper on both sides of the composite material in the overlapping area of ​​the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle around the composite material and the R corner position in the central raised area of ​​the bottom mold according to the method of steps 4.5 to 4.6, and perform vacuum compaction and removal;

[0097] Step 4.8: Repeat step 4.7 until the composite material layer on the upper mold is completed;

[0098] Step 4.9: flip and lay the composite material outside the overlapped area of ​​the upper mold and the bottom mold layer by layer onto the upper mold, lay 1 to 3 layers of composite material each time flipping, arrange the air guide fiber bundle at the outer edge of the composite material, and perform vacuum compaction and removal according to the method of step 4.5 until all composite material layers of the upper mold are flipped and laid; one end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging;

[0099] Step 4.10 Place a twist strip at the T-shaped R corner between the upper mold, the bottom mold and the peripheral mold in the forming mold;

[0100] Step 4.11 lays the composite material on the periphery of the combined mold formed by the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle on the outer edge of the outermost layer of composite material, and perform vacuum compaction and removal according to the method of step 4.5. One end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the glue-free glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging; the starting position of the layer avoids the corner of the molding mold, the starting position is 15-25 mm away from the corner, and the starting positions of each layer are staggered by 15-30 mm.

[0101] Step 5: After the composite material is stacked, close the mold and then seal it; the process of closing the mold body is as follows: assemble the silicone soft mold with the upper mold, install the peripheral mold to the outer periphery of the upper mold and the bottom mold through connecting bolts, and connect the top mold with the peripheral mold and the upper mold. To prevent cloth from being caught, the mold should be opened repeatedly for inspection to eliminate defects until the clearance between each mold is no more than 0.2mm; after ensuring that there is no cloth caught, complete the mold closing.

[0102] The specific packaging process is as follows: laying an isolation film on the molding mold after mold closing, and the outer contour size of the isolation film can completely cover the molding mold; laying a breathable felt on the isolation film, and placing a vacuum nozzle on the breathable felt; laying a vacuum bag on the breathable felt, and laying a sealing strip around the flat workbench to ensure that the sealing strip is tightly connected to the vacuum bag; evacuating, and the vacuum degree is ≥0.090MPa.

[0103] Step 6: Perform vacuum testing on the packaged composite material; when the vacuum degree in the vacuum bag reaches 0.09MPa until the vacuum degree stabilizes, disconnect or turn off the vacuum source after 15 minutes, and the vacuum gauge reading drops by no more than 0.017Mpa within 5 minutes.

[0104] Step 7: Curing the composite material; in step 7, the encapsulated molding mold is operated into the curing equipment, and the curing parameters are: the vacuum degree in the vacuum bag is not less than -0.090MPa, the room temperature is heated to 82℃±10℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 30min-60min, and the temperature is further heated to 127℃±2℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 120min; the temperature is reduced to below 60℃ at a cooling rate of ≤5℃ / min, and the curing equipment is taken out; during the entire curing cycle, the pressure in the vacuum bag should be maintained at not less than -0.090MPa.

[0105] Step 8: Remove the vacuum nozzle on the breathable felt, remove the vacuum bag, breathable felt and non-porous isolation film; use non-metallic tools to demould and open the mold, and clean the excess materials on the surface of the molding mold;

[0106] Step 9: Check whether the formed composite material has any damage or excess;

[0107] Step 10: If there are delamination defects in the composite material after molding, use high temperature resistant paste glue and repair it according to the following scheme:

[0108] 10.1 Drill a φ2.1mm hole at the upper and lower edges of the defect;

[0109] 10.2 Inject glue into the defect from the lower hole until the glue overflows from the upper hole;

[0110] 10.3 Seal the two holes with tape;

[0111] 10.4 After the injected glue solidifies, remove the tape and grind it smooth.

[0112] A second embodiment of the present invention is:

[0113] A composite material structure non-autoclave combined mold forming method of the present invention is used to form a certain type of machine inclined beam rib as follows:

[0114] 1. Preparation of molding mold.

[0115] Complete the mold release agent coating and surface cleaning of each combined mold surface of the inclined beam rib in the molding process. Ensure that the tooling has reached room temperature and there is no moisture on the surface. Scrub the tooling work surface with acetone / methyl ethyl ketone to ensure that the tooling surface is clean and grease-free. Use the mold release agent FREKOTE44NC in a well-ventilated area.

[0116] 1) Check the area where the putty strips are laid with tape to prevent the release agent from contaminating the bagging area; 2) The combined molds of the inclined beam ribs are used molds, so use a brush or soft cloth dipped in the release agent to cross-coat a thin layer of FREKOTE44NC on the surface of each mold. 3) Dry at 25℃ for 15 minutes between each layer. 4) After drying, start the composite material laying operation.

[0117] 2. Prepare auxiliary materials.

[0118] Prepare auxiliary materials according to the auxiliary materials required for rib No. 3 of the inclined beam, as shown in the following table.

[0119]

[0120]

[0121] 3. Cutting of composite materials.

[0122] After the composite materials used for the inclined beam ribs are thawed in the clean room for 6 hours, the materials are cut according to the composite material structure, layup and dimensions, and the information is marked.

[0123] 4. Lay up composite materials in autoclave.

[0124] 4.1 Place the forming mold used for the inclined beam rib on a flat workbench in a clean room with a temperature of 18℃~26℃ and a relative humidity of 15%~65%;

[0125] 4.2 Lay the first layer of composite material on the bottom mold of the inclined beam rib forming mold according to the boundaries and directions shown by the laser projector. Use a compaction tool to comb along the parallel direction of the composite material fibers or the warp direction of the fabric to facilitate the removal of air inclusions during laying and the fit between the composite material and the forming mold at the R angle position.

[0126] When laying composite materials, make cuts and overlap them with a 20mm overlap. The cuts between layers should be staggered by 20mm.

[0127] When laying the first layer of composite material on the bottom mold of the molding mold, do not tear off the isolation film on the surface of the prepreg when laying and compacting at the R corner of the bottom mold. Use a laying and compacting tool to compact the first layer of composite material through the isolation film to protect the fibers. In addition, try to scrape and press parallel to the fiber direction of the R corner when compacting.

[0128] 4.3 After laying the first layer of composite material on the bottom mold of the forming mold, arrange the air-conducting fiber bundle between the outer edge of the composite material and the bottom mold. The air-conducting fiber bundle is a dry glass fiber material, and the width of each fiber bundle is 10mm; one end of the air-conducting fiber bundle is placed outside the edge line of the first layer of composite material, and the connection length with the first layer of composite material is 25mm; the other end of the air-conducting fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and can be connected to the breathable felt during packaging;

[0129] 4.4 Lay the non-glue polytetrafluoroethylene cloth on the first layer of composite material, and open a plurality of equally spaced air guide windows at the R corners of the non-glue polytetrafluoroethylene cloth;

[0130] 4.5 Insert one end of the air-conducting fiber bundle into the air-conducting window at the R corner of the non-glue polytetrafluoroethylene cloth and connect it to the R corner of the first layer of composite material. The length of the other end of the air-conducting fiber bundle meets the requirements of being connected to the non-glue glass cloth during subsequent vacuum compaction and being connected to the breathable felt during packaging. After the air-conducting fiber bundle is drawn out, the remaining air-conducting window gap is sealed with a non-porous film or tape; vacuum compaction is performed. After the vacuum compaction is completed, the vacuum bag, vacuum nozzle, non-glue glass fiber cloth, non-glue polytetrafluoroethylene cloth and the air-conducting fiber bundle at the R corner are removed;

[0131] The specific process of vacuum compaction is as follows: lay glue-free polytetrafluoroethylene cloth on the surface of the composite material, the outer edge size D2 of the glue-free polytetrafluoroethylene cloth is larger than the outer edge size D1 of the composite material layer, and D2-D1≥10mm is satisfied; lay glue-free glass fiber cloth on the surface of the glue-free polytetrafluoroethylene cloth, the outer edge size D3>D2, and no bridging is generated during vacuuming; the glue-free glass fiber cloth is sealed with high-temperature resistant tape on all sides to ensure that the fibers do not fall off, and the air-conducting fiber bundle is connected to the glue-free glass fiber cloth; place a vacuum nozzle above the glue-free glass fiber cloth, lay a vacuum bag on the glue-free glass fiber cloth, lay a sealing strip around the molding mold, ensure that the sealing strip is tightly connected to the vacuum bag, and vacuum compact, the vacuum degree is not less than 0.09MPa, and the time is at least 15min; then remove the vacuum nozzle, remove the vacuum bag, the glue-free polytetrafluoroethylene cloth, the glue-free glass fiber cloth and the air-conducting fiber bundle at the R corner;

[0132] 4.6 According to the method of step 4.2, after laying 1 to 3 layers of composite materials on the bottom mold of the forming mold, arrange the air guide fiber bundle on the outer edge of the top composite material, then lay the glue-free polytetrafluoroethylene cloth on the top composite material, and open a plurality of equally spaced air guide windows at the R corner of the glue-free polytetrafluoroethylene cloth; according to the method of step 4.5, arrange the air guide fiber bundle at the R corner of the top composite material and perform vacuum compaction and removal; one end of the air guide fiber bundle is placed outside the edge line of the top composite material, and the connection length with the top composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the glue-free glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging;

[0133] 4.7 Repeat step 4.6 until the composite material layer on the bottom mold is completed, and the upper mold is installed on the bottom mold with the composite material layer laid, so as to complete the combination of the upper mold and the bottom mold;

[0134] 4.8 Lay the composite material layer of the upper mold in the forming mold on the bottom mold;

[0135] When laying the composite material layer of the upper mold, only remove the isolation film and isolation paper on both sides of the composite material in the overlapping area of ​​the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle at the periphery of the composite material and the R corner position in the central raised area of ​​the bottom mold according to the method of steps 4.5 to 4.6, and perform vacuum compaction and removal; this step can effectively improve the interlayer strength between the composite material layers in the area where the bottom mold and the upper mold return; repeat step 4.7 until the composite material layer on the upper mold is completed;

[0136] 4.9 Flip and lay the composite materials outside the overlapped area of ​​the upper mold and the bottom mold layer by layer to the upper mold, lay 1 to 3 layers of composite materials each time, arrange the air-conducting fiber bundle at the outer edge of the composite materials, and perform vacuum compaction and removal according to the method in step 4.5 until all the composite material layers of the upper mold are flipped and laid; one end of the air-conducting fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air-conducting fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging;

[0137] 4.10 Place a twist strip at the T-shaped R corner between the upper die, bottom die and peripheral die in the forming die;

[0138] 4.11 Lay the composite material on the periphery of the combined mold formed by the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle on the outer edge of the outermost layer of composite material, and perform vacuum compaction and removal according to the method in step 4.5. One end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20mm; the length of the other end of the air guide fiber bundle is sufficient to be connected to the glue-free glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging; the starting position of the layer should avoid the corner of the molding mold, and the starting position should be 15-25mm away from the corner, and the starting positions of each layer should be staggered by 15-30mm.

[0139] 5. After the composite material is stacked, it is molded and then packaged.

[0140] Assemble the silicone soft mold with the upper mold, install the peripheral mold to the outer periphery of the upper mold and the bottom mold through connecting bolts, and connect the top mold with the peripheral mold and the upper mold. To prevent cloth jamming, the mold should be opened repeatedly for inspection and defects should be eliminated until the mold clearance of each mold is no more than 0.2mm; after ensuring that there is no cloth jamming, complete the mold closing.

[0141] Place an isolation film on the molding mold after mold closing, and the outer contour size of the isolation film can completely cover the molding mold; place a breathable felt on the isolation film, and place a vacuum nozzle on the breathable felt; place a vacuum bag on the breathable felt, and lay a sealing strip around the flat workbench to ensure that the sealing strip is tightly connected to the vacuum bag; vacuum is drawn, and the vacuum degree is ≥0.090MPa.

[0142] 6. Perform vacuum testing on the encapsulated composite material.

[0143] When the vacuum degree in the vacuum bag reaches 0.09MPa until the vacuum degree is stable, disconnect or turn off the vacuum source after 15 minutes, and the vacuum gauge reading drops by no more than 0.017Mpa within 5 minutes. The vacuum degree is an effective guarantee for the quality of the R corner position of the non-autoclave composite material structure. Therefore, vacuum testing of the packaged composite material must be carried out before curing.

[0144] 7. Curing the composite material.

[0145] The packaged composite material is transported to the curing equipment with the following curing parameters: the vacuum degree in the vacuum bag is not less than -0.090MPa, the temperature is raised from room temperature to 82℃±10℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 30min-60min, the temperature is further raised to 127℃±2℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 120min; the temperature is lowered to below 60℃ at a cooling rate of ≤5℃ / min, and the product is taken out of the curing equipment; during the whole curing cycle, the pressure in the vacuum bag should be kept at not less than -0.090MPa.

[0146] 8. Demoulding.

[0147] Remove the vacuum nozzle, vacuum bag, breathable felt, isolation film, fiberglass cloth, etc. Use non-metallic tools to carefully demould and clean the excess on the mold surface; do not damage the product and mold surface.

[0148] 9. Inspection.

[0149] Check whether the inclined beam ribs are damaged or have any extra material. Use non-destructive testing to test the internal quality of the inclined beam ribs. The porosity test of the inclined beam ribs is shown in the following table.

[0150]

[0151] In summary, the oblique beam rib manufactured by the non-autoclave combined mold forming method of the composite material structure of the present invention does not have defects such as delamination and lack of glue, and its porosity meets the product performance requirements. The curing furnace is used for curing, which effectively reduces the manufacturing cost compared with the autoclave forming.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A composite material structure non-autoclave combined mold forming method, characterized in that: The following steps are involved: Step 1: Preparation of molding mold; Step 2: Preparation of auxiliary materials; Step 3: Cutting composite materials; Step 4: Non-autoclave composite lay-up; Step 5: After the composite material is stacked, mold it and then package it; Step 6: Perform vacuum testing on the packaged composite material; Step 7: Curing the composite material.

2. The composite material structure non-autoclave combined mold forming method according to claim 1, characterized in that: Step 1: Preparation of the molding mold: After cleaning the surface of each mold assembly, apply a release agent, the type of release agent is FREKOTE44NC; when a new or repaired molding mold is used for the first time, use a brush or soft cloth dipped in the release agent, and apply 3 layers of FREKOTE thinly and crosswise; when using the release agent on a molding mold that has been used with the release agent again, do not apply too much release agent; The specific process of coating the release agent on the surface of the molding mold is as follows: 1) Check the area where the tape is used to isolate the putty strips to prevent the release agent from contaminating the bagging area; 2) On the mold surface, use a brush or soft cloth to dip the release agent and apply a thin cross-coat; 3) After each layer of release agent is applied, dry it at 25°C for 15 minutes; 4) After the release agent is dry, proceed with the composite material laying operation.

3. The composite material structure non-autoclave combined mold forming method according to claim 2, characterized in that: The auxiliary materials in step 2 include isolation film, high temperature resistant tape, non-adhesive polytetrafluoroethylene cloth, non-adhesive glass fiber cloth, vacuum bag, sealing strip, and paving and compacting tools; ensure that the brand and quantity of the above auxiliary materials meet the manufacturing requirements.

4. The composite material structure non-autoclave combined mold forming method according to claim 3, characterized in that: Step 3 of cutting the composite material specifically includes: after the composite material is thawed in the clean room, the cutting is completed according to the composite material structure layering and size, and the information is marked. Among them, the thawing time of the composite material varies with the total thickness of the composite material, and the thawing time is at least 6 hours.

5. The composite material structure non-autoclave combined mold forming method according to claim 4, characterized in that: Step 4: Non-autoclave composite material layup specifically includes the following steps: Step 4.1 Place the molding mold on a flat workbench in a clean room with a temperature of 18°C ​​to 26°C and a relative humidity of 15% to 65%; Step 4.2: Lay the first layer of composite material on the bottom mold of the forming mold according to the boundary and direction shown by the laser projector, and use a scraper to comb along the parallel direction of the composite material fiber or the warp direction of the fabric; When laying composite materials, it is allowed to make cuts, overlap the cuts, overlap 15-25mm, and stagger the cuts between layers by 15-30mm; When laying the first layer of composite material on the bottom mold of the forming mold, do not tear off the isolation film on the surface of the prepreg when laying and compacting at the R corner of the bottom mold. Use a laying and compacting tool to compact the first layer of composite material through the isolation film to protect the fiber. In addition, try to scrape and press parallel to the fiber direction of the R corner when compacting; Step 4.3 After laying the first layer of composite material on the bottom mold of the forming mold, an air-conducting fiber bundle is arranged between the outer edge of the composite material and the bottom mold, the air-conducting fiber bundle is a dry glass fiber material, and the width of each fiber bundle is 5 mm to 10 mm; one end of the air-conducting fiber bundle is placed outside the edge line of the first layer of composite material, and the connection length with the first layer of composite material is not less than 20 mm; the other end of the air-conducting fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging; Step 4.4: Lay a non-adhesive polytetrafluoroethylene cloth on the first layer of composite material, and open a plurality of equally spaced air guide windows at the R corners of the non-adhesive polytetrafluoroethylene cloth; Step 4.5: insert one end of the air-conducting fiber bundle into the air-conducting window at the R corner of the adhesive-free polytetrafluoroethylene cloth, and connect it to the R corner of the first layer of composite material. The length of the other end of the air-conducting fiber bundle meets the requirements of being connected to the adhesive-free glass cloth during subsequent vacuum compaction and being connected to the breathable felt during packaging. After the air-conducting fiber bundle is drawn out, the remaining air-conducting window gap is sealed with a non-porous film or tape; vacuum compaction is performed. After the vacuum compaction is completed, the vacuum bag, vacuum nozzle, adhesive-free glass fiber cloth, adhesive-free polytetrafluoroethylene cloth and the air-conducting fiber bundle at the R corner are removed; The specific process of vacuum compaction is as follows: lay glue-free polytetrafluoroethylene cloth on the surface of the composite material, the outer edge size D2 of the glue-free polytetrafluoroethylene cloth is larger than the outer edge size D1 of the composite material layer, and D2-D1≥10mm is satisfied; lay glue-free glass fiber cloth on the surface of the glue-free polytetrafluoroethylene cloth, the outer edge size D3>D2, and no bridging is generated during vacuuming; the glue-free glass fiber cloth is sealed with high-temperature resistant tape on all sides to ensure that the fibers do not fall off, and the air-conducting fiber bundle is connected to the glue-free glass fiber cloth; place a vacuum nozzle above the glue-free glass fiber cloth, lay a vacuum bag on the glue-free glass fiber cloth, lay a sealing strip around the molding mold, ensure that the sealing strip is tightly connected to the vacuum bag, and vacuum compact, the vacuum degree is not less than 0.09MPa, and the time is at least 15min; then remove the vacuum nozzle, remove the vacuum bag, the glue-free polytetrafluoroethylene cloth, the glue-free glass fiber cloth and the air-conducting fiber bundle at the R corner; Step 4.6: According to the method of step 4.2, after laying 1 to 3 layers of composite materials on the bottom mold of the forming mold, arrange an air guide fiber bundle on the outer edge of the uppermost composite material, then lay a non-glue polytetrafluoroethylene cloth on the uppermost composite material, and open a plurality of equally spaced air guide windows at the R corner of the non-glue polytetrafluoroethylene cloth; according to the method of step 4.5, arrange an air guide fiber bundle at the R corner of the uppermost composite material and perform vacuum compaction and removal; one end of the air guide fiber bundle is placed outside the edge line of the uppermost composite material, and the connection length with the uppermost composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging; Step 4.7: Repeat step 4.6 until the composite material layer on the bottom mold is completed, and the upper mold is installed on the bottom mold on which the composite material layer is laid, so as to complete the combination of the upper mold and the bottom mold; Step 4.8: Laying the composite material layer of the upper mold in the molding mold on the bottom mold; When laying the composite material layer of the upper mold, only remove the isolation film and isolation paper on both sides of the composite material in the overlapping area of ​​the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle around the composite material and the R corner position in the central raised area of ​​the bottom mold according to the method of steps 4.5 to 4.6, and perform vacuum compaction and removal; Step 4.8: Repeat step 4.7 until the composite material layer on the upper mold is completed; Step 4.9: flip and lay the composite material outside the overlapped area of ​​the upper mold and the bottom mold layer by layer onto the upper mold, lay 1 to 3 layers of composite material each time flipping, arrange the air guide fiber bundle at the outer edge of the composite material, and perform vacuum compaction and removal according to the method of step 4.5 until all composite material layers of the upper mold are flipped and laid; one end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the non-glue glass cloth during subsequent vacuum compaction, and to be connected to the breathable felt during packaging; Step 4.10 Place a twist strip at the T-shaped R corner between the upper mold, the bottom mold and the peripheral mold in the forming mold; Step 4.11 lays the composite material on the periphery of the combined mold formed by the upper mold and the bottom mold. After laying 1 to 3 layers of composite material, arrange the air guide fiber bundle on the outer edge of the outermost layer of composite material, and perform vacuum compaction and removal according to the method of step 4.

5. One end of the air guide fiber bundle is placed outside the edge line of the composite material, and the connection length with the composite material is not less than 20 mm; the other end of the air guide fiber bundle is long enough to be connected to the glue-free glass cloth during subsequent vacuum compaction, and to the breathable felt during packaging; the starting position of the layer avoids the corner of the molding mold, the starting position is 15-25 mm away from the corner, and the starting positions of each layer are staggered by 15-30 mm.

6. The composite material structure non-autoclave combined mold forming method according to claim 5, characterized in that: In step 5, the mold body is assembled as follows: assemble the silicone soft mold with the upper mold, install the peripheral mold to the outer periphery of the upper mold and the bottom mold through connecting bolts, and connect the top mold with the peripheral mold and the upper mold. To prevent cloth from being stuck, the mold should be opened repeatedly for inspection to eliminate defects until the mold clearance of each mold is no more than 0.2 mm. After ensuring that there is no cloth jam, complete the mold closing.

7. The composite material structure non-autoclave combined mold forming method according to claim 6, characterized in that: In step 5, the specific packaging process is as follows: laying an isolation film on the molding mold after mold closing, and the outer contour size of the isolation film can completely cover the molding mold; laying a breathable felt on the isolation film, and placing a vacuum nozzle on the breathable felt; laying a vacuum bag on the breathable felt, and laying a sealing strip around the flat workbench to ensure that the sealing strip is tightly connected to the vacuum bag; evacuating, and the vacuum degree is ≥0.090MPa.

8. The composite material structure non-autoclave combined mold forming method according to claim 7, characterized in that: In step 6, when the vacuum degree in the vacuum bag reaches 0.09 MPa until the vacuum degree stabilizes, the vacuum source is disconnected or turned off after 15 minutes, and the vacuum gauge reading drops by no more than 0.017 MPa within 5 minutes.

9. The composite material structure non-autoclave combined mold forming method according to claim 8, characterized in that: In step 7, the encapsulated molding mold is operated into the curing equipment, and the curing parameters are: the vacuum degree in the vacuum bag is not less than -0.090MPa, the room temperature is heated to 82℃±10℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 30min-60min, and the temperature is further heated to 127℃±2℃, the heating rate is 0.5~3℃ / min, and the temperature is kept for 120min; the temperature is reduced to below 60℃ at a cooling rate of ≤5℃ / min, and the product is taken out of the curing equipment; during the entire curing cycle, the pressure in the vacuum bag should be maintained at not less than -0.090MPa.

10. The composite material structure non-autoclave combined mold forming method according to claim 9, characterized in that: The method further comprises: Step 8: Remove the vacuum nozzle on the breathable felt, remove the vacuum bag, breathable felt and non-porous isolation film; use non-metallic tools to demould and open the mold, and clean the excess materials on the surface of the molding mold; Step 9: Check whether the formed composite material has any damage or excess; Step 10: If there are delamination defects in the composite material after molding, use high temperature resistant paste glue and repair it according to the following scheme: 10.1 Drill a φ2.1mm hole at the upper and lower edges of the defect; 10.2 Inject glue into the defect from the lower hole until the glue overflows from the upper hole; 10.3 Seal the two holes with tape; 10.4 After the injected glue solidifies, remove the tape and grind it smooth.

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