Die for forming thermosetting resin matrix composite reinforcing rib and preparation method of reinforcing rib

Abstract

The invention provides a mold for forming a thermosetting resin matrix composite reinforcing rib and a preparation method of the reinforcing rib. A groove is formed; the mold convex block is arranged in the groove; the mold set is located above the mold protruding block and provided with an inner cavity with an opening in the bottom, and the inner cavity and the upper surface of the mold protruding block are spliced to define a mold cavity suitable for reinforcing rib forming; the first pressing block is located on one side of the mold set and the mold protruding block, the second pressing block is located on the other side of the mold set and the mold protruding block, the pressing blocks can be inserted into gaps between the grooves and the mold protruding block, and the pressing blocks apply pressure to the side face of the mold set through the effect of the grooves on the pressing blocks; the groove has a dip angle at the top edge of the pressing block insertion part; and the pressing block, the mold convex block and the mold group are fixed through fasteners. According to the mold and the preparation method, the metal mold is used for multi-dimensional pressurization and mold closing net size forming, the produced reinforcing rib structure is good in size stability, the production cost of the reinforcing rib structure is reduced, and the production efficiency of products is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a mold for forming a thermosetting resin-based composite material reinforcing rib and a method for preparing the reinforcing rib. Background Art

[0002] Thermosetting resin-based fiber-reinforced composites have the characteristics of high specific modulus, high tensile strength and light weight. In recent years, they have received increasing attention in the aerospace field. A class of advanced thermosetting composite materials represented by carbon fiber reinforced bismaleimide resins are increasingly used in primary and secondary load-bearing components in the aviation field. Composite stiffener components are a type of structure widely used in engineering. They combine the excellent properties of composite materials with the strengthening effect of stiffeners, providing various structures with higher load-bearing capacity and stability. Composite stiffener components are usually embedded or attached to the composite matrix in a specific shape (such as T-type, I-type, hat-type, L-type, etc.) to enhance the stiffness and strength of the overall structure.

[0003] Existing thermosetting composite reinforcement components are mostly cured by autoclave technology, and the multi-dimensional pressurization design is realized by filling gas in the autoclave. The process is to lay "C"-shaped and "L"-shaped structural component preforms on the surface of the mold male mold, and then combine the "C"-shaped and "L"-shaped structural component preforms into I-shaped structural component preforms through tooling, and then cover the surface of the preforms with vacuum bags, adhesive absorbing materials, porous membranes and other auxiliary materials. The male mold is mostly a soft mold that expands when heated to provide a certain pressure for resin curing. The Chinese patent document with publication number CN108973159A discloses a composite material I-shaped long spar forming process, which provides a hot press curing mold and curing process for thermosetting materials in an autoclave. The pressure of the gas filled in the autoclave is used to form a uniform pressure on the composite material, so the composite material I-shaped long spar can be easily formed in the autoclave, but the autoclave equipment is expensive, its molding cost is high, and the molding process is relatively complicated, time-consuming and labor-intensive, and it is difficult to meet the requirements of industrialization. In addition, the surface of the autoclave-cured product is a vacuum-assisted material, the shape accuracy of the prepared material is poor, the positive mold is a soft mold product with low controllability of structural dimensions, and the products produced need to undergo secondary processing before they can be used, which increases production costs and extends the production cycle of the product; currently, the curing temperature of some high-temperature resistant resins (polyimide-based resins) is above 400°C, and the autoclave has limited curing capacity for these resins. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a mold for forming thermosetting resin-based composite material reinforcement ribs and a method for preparing the reinforcement ribs. The metal mold is pressurized in multiple dimensions and the net size of the closed mold is formed. The reinforcement rib structure produced has good dimensional stability, which reduces the production cost of the reinforcement rib structure and improves the production efficiency of the product.

[0005] In order to solve the above problems, one aspect of the present invention provides a mold for forming a thermosetting resin-based composite material reinforcement rib, comprising:

[0006] A base; the base is provided with a groove;

[0007] A mold protrusion, wherein the mold protrusion is arranged in the groove;

[0008] A mold set, the mold set is located above the mold convex block, the mold set is provided with an inner cavity with an open bottom, and the inner cavity of the mold set is assembled with the upper surface of the mold convex block to form a cavity suitable for forming the reinforcing rib;

[0009] a first pressing block, the first pressing block being located at one side of the mold set and the mold protrusion and being insertable into the gap between the groove and the mold protrusion; when the first pressing block is inserted into the gap between the groove and the mold protrusion, the first pressing block applies pressure to the side of the mold set through the action of the groove on the first pressing block; the groove is provided with an inclination at the top edge where the first pressing block is inserted;

[0010] a second pressing block, the second pressing block is located on the other side of the mold set and the mold protrusion, and can be inserted into the gap between the groove and the mold protrusion; when the second pressing block is inserted into the gap between the groove and the mold protrusion, the second pressing block applies pressure to the side of the mold set through the action of the groove on the second pressing block; the groove is provided with an inclination at the top edge where the first pressing block is inserted;

[0011] The first pressing block, the second pressing block, the mold protrusion, and the mold set are fixed by fasteners.

[0012] Preferably, the reinforcing rib comprises a web, a flange, a first side plate and a second side plate; the flange is located at the bottom of the web and is perpendicular to the web, the first side plate is arranged at an end of one end of the web, and the second side plate is arranged at an end of the other end of the web;

[0013] The top of the mold convex block is provided with a molding surface matching the bottom surface of the flange;

[0014] The mold set comprises:

[0015] A first web plate mold is located on one side above the mold protrusion, and the bottom and inner side of the first web plate mold are respectively provided with molding surfaces matching the top surface of one side of the flange and the side surface of one side of the web, and both ends of the first web plate mold are respectively provided with molding surfaces matching the inner side surfaces of the first side plate and the second side plate;

[0016] A second web plate mold is located on the other side above the mold protrusion, and the bottom and inner side of the second web plate mold are respectively provided with molding surfaces matching the other side top surface of the flange, the other side side of the web plate, and the top surface of the web plate, and both ends of the second web plate mold are respectively provided with molding surfaces matching the inner side surfaces of the first side plate and the second side plate;

[0017] A first side panel mold, provided with a molding surface matching the outer side surface of the first side panel;

[0018] A second side panel mold, provided with a molding surface matching the outer side surface of the second side panel;

[0019] The first web plate mold, the second web plate mold, the first pressing block, the second pressing block, the first side plate mold, the second side plate mold, and the mold protrusion are fixed by fasteners.

[0020] Preferably, the first pressing block is connected and fastened to the first web mold by a first fastening screw; the second pressing block is connected and fastened to the second web mold by a second fastening screw; the first pressing block, the first web mold, the second web mold, and the second pressing block are also connected and fastened by a third fastening screw that penetrates through;

[0021] The first pressing block, the mold convex block, and the second pressing block are connected and fastened by a fourth fastening screw that penetrates through the pressing block;

[0022] The bottom of the first pressing block and the bottom of the second pressing block are connected and fastened to the bottom of the groove by a fifth fastening screw;

[0023] The first side panel mold is connected and fastened to the first pressing block and the second pressing block via a sixth fastening screw; the second side panel mold is connected and fastened to the first pressing block and the second pressing block via a seventh fastening screw.

[0024] Preferably, the inclination angle is 1-10°.

[0025] Preferably, the reinforcing rib is a negative curvature reinforcing rib;

[0026] The first web mold includes a first petal, a second petal and a third petal arranged in sequence from one end to the other end; the first petal is connected to the second petal by an eighth fastening screw; the third petal is connected to the second petal by a ninth fastening screw;

[0027] The second web mold includes a fourth petal, a fifth petal and a sixth petal arranged in sequence from one end to the other end; the fourth petal is connected to the fifth petal by a tenth fastening screw; the sixth petal is connected to the fifth petal by an eleventh fastening screw.

[0028] Another aspect of the present invention provides a method for preparing a thermosetting resin-based composite material reinforcement rib by closed-die net size molding, comprising the following steps:

[0029] S1. Using the above-mentioned thermosetting resin-based composite material reinforcement molding mold, the thermosetting resin-based prepreg is covered in the mold cavity of the mold;

[0030] S2. Precuring the thermosetting resin-based prepreg in the cavity so that it is pre-compacted;

[0031] S3. The first pressing block and the second pressing block are respectively arranged on both sides of the mold set and the mold protrusion, and are fastened to the mold set and the mold protrusion, and are pressurized from top to bottom by a press machine, and are cured by heating at the same time.

[0032] Preferably, step S1 specifically includes:

[0033] S101. Covering the bottom, sides and ends of the first web mold with a thermosetting resin-based prepreg to obtain a first preform having an L-shaped longitudinal section;

[0034] S102. Covering the bottom, sides and ends of the second web mold with a thermosetting resin-based prepreg to obtain a second preform having an L-shaped longitudinal section;

[0035] S103. Arrange the first web mold and the second web mold on the mold protrusion, splice the first preform and the second preform, and lay a skin on the splicing surface.

[0036] Preferably, in step S2, the pre-curing conditions are to heat the temperature to 60°C to 120°C at a heating rate of 60 to 90°C / h; and then keep the temperature at a pressure of 0.3 to 1 MPa for 0.5 to 2 hours;

[0037] In step S3, the temperature is raised to 110°C to 280°C at a heating rate of 20 to 80°C / h for curing; and then kept at a pressure of 0.3 to 5 MPa for 1 to 6 hours.

[0038] Preferably, step S3 specifically includes:

[0039] S301. The first pressing block and the second pressing block are respectively arranged on the outside of the first web mold and the second web mold, and the first pressing block is connected and fastened to the first web mold by a third fastening screw; the second pressing block is connected and fastened to the second web mold by a fourth fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0040] S302. The first pressing block, the mold protrusion, and the second pressing block are connected and fastened by a first through-going fastening screw; the first pressing block, the first web mold, the second web mold, and the second pressing block are connected and fastened by a seventh through-going fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0041] S303. Connect and tighten the bottom of the first pressing block and the second pressing block to the bottom of the groove through a second fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0042] S304. Connect and fasten the first side panel mold to the first pressing block and the second pressing block through the fifth fastening screw; connect and fasten the second side panel mold to the first pressing block and the second pressing block through the sixth fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0043] S305. Use a press to apply pressure from top to bottom while heating and curing.

[0044] Preferably, in step S1, the thermosetting resin-based prepreg is laid in a quasi-isotropic laying manner of [+45° / 0° / -45° / 90° / -45° / 0° / +45°]n, where n is a natural number;

[0045] The reinforcing fibers in the thermosetting resin-based prepreg are continuous fibers; the mass content of the resin in the thermosetting resin-based prepreg is 20-43%; the single-layer thickness of the prepreg is 0.02-0.35 mm; the content of volatiles is 2.5-5%; the surface density of the reinforcing fibers is 100-380 g / m 3 ; The reinforcing material is in the form of at least one of a unidirectional tape structure, plain weave, and twill fabric.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The mold for forming thermosetting resin-based composite material reinforcement ribs and the method for preparing the reinforcement ribs of the present invention can perform closed-mold net-size molding of thermosetting resin-based composite material reinforcement ribs. The mold set and the pressing block used can both adopt metal molds. Compared with the auxiliary molding of vacuum auxiliary materials, soft molds, etc. in the autoclave, the appearance accuracy of the prepared materials is poor and secondary processing is required. The mold of the present application performs closed-mold net-size molding, and the reinforcement rib structure produced has good dimensional stability and does not require secondary processing; the production cost of the reinforcement rib structure is reduced and the production efficiency is improved; closed-mold molding is to use temperature control equipment to heat the mold There is no curing temperature limit, and the closed mold molding process has a wider range of curing resin matrices, which broadens the use temperature range of carbon fiber composite I-shaped reinforcement rib structural parts, and is conducive to the wider application of this type of structure in the aerospace field; when the first pressing block and the second pressing block are inserted into the groove, due to the inclination angle set at the top edge of the groove, the insertion of the pressing block has a certain guiding effect and the effect of inclined force, which makes the mold installation operation easier on the one hand, and on the other hand, the force exerted by the inclination angle on the pressing block can be decomposed into a horizontal force, under the action of this force, the pressing block presses the side of the mold group and the prepreg to further compact the prepreg. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic structural diagram of a mold for forming a reinforcing rib of a thermosetting resin-based composite material according to Example 1 of the present invention;

[0049] Figure 2 It is a schematic structural diagram of the mold for forming reinforcing ribs of thermosetting resin-based composite materials according to Example 1 of the present invention without the first pressing block;

[0050] Figure 3 It is a schematic structural diagram of the mold for forming reinforcing ribs of thermosetting resin-based composite materials described in Example 1 of the present invention without the first pressing block and the first side plate mold;

[0051] Figure 4 It is a top view of the mold for forming a thermosetting resin-based composite material reinforcing rib according to Example 1 of the present invention, without the first pressing block and the first side plate mold;

[0052] Figure 5 is a cross-sectional view of a mold for forming a thermosetting resin-based composite material reinforcement rib according to Example 1 of the present invention;

[0053] Figure 6 It is a schematic diagram of the structure of the reinforcing rib prepared in Example 2 of the present invention.

[0054] Among them: 1-base; 2-groove; 3-mold protrusion; 4-mold group; 41-first web mold; 411-first petal; 412-second petal; 413-third petal; 42-second web mold; 421-fourth petal; 422-fifth petal; 423-sixth petal; 43-first side panel mold; 44-second side panel mold; 5-first pressure block; 6-second pressure block; 7-reinforcement rib; 71-web; 72-flange; 73-first side panel; 74-second side panel; 8-first fastening screw; 9-inclination; 10-third fastening screw; 11-fourth fastening screw; 12-fifth fastening screw; 13-sixth fastening screw; 14-seventh fastening screw; 15-eighth fastening screw; 16-ninth fastening screw; 17-tenth fastening screw; 18-eleventh fastening screw. DETAILED DESCRIPTION

[0055] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Example 1

[0057] like Figure 1-Figure 5 As shown, the mold for forming the thermosetting resin-based composite material reinforcement rib of this embodiment includes:

[0058] A base 1; a groove 2 is provided on the base 1;

[0059] A mold protrusion 3, the mold protrusion 3 is arranged in the groove 2;

[0060] The mold set 4 is located above the mold protrusion 3. The mold set 4 is provided with an inner cavity with an open bottom. The inner cavity of the mold set 4 is assembled with the upper surface of the mold protrusion 3 to form a cavity suitable for forming the reinforcing ribs.

[0061] The first pressing block 5 is located on one side of the mold set 4 and the mold protrusion 3, and can be inserted into the gap between the groove 2 and the mold protrusion 3; when the first pressing block 5 is inserted into the gap between the groove 2 and the mold protrusion 3, the first pressing block 5 applies pressure to the side of the mold set 4 through the action of the groove 2 on the first pressing block 5; the groove 2 is provided with an inclination at the top edge of the first pressing block 5 insertion position;

[0062] The second pressing block 6 is located on the other side of the mold set 4 and the mold protrusion 3, and can be inserted into the gap between the groove 2 and the mold protrusion 3; when the second pressing block 6 is inserted into the gap between the groove 2 and the mold protrusion 3, the second pressing block 6 applies pressure to the side of the mold set 4 through the action of the groove 2 on the second pressing block 6; the groove 2 is provided with an inclination at the top edge where the first pressing block 5 is inserted;

[0063] The first pressing block 5, the second pressing block 6, the mold protrusion 3 and the mold assembly 4 are fixed by fasteners.

[0064] In the mold for forming thermosetting resin-based composite material reinforcement ribs of the embodiment of the present invention, when working, the thermosetting resin-based prepreg is spread in the inner cavity of the mold group, and its volume is larger than the volume of the inner cavity. It is initially compacted by extrusion of the inner cavity of the mold group and the mold protrusion, and then the first pressing block and the second pressing block are inserted into the groove. The extrusion of the mold group further compacts the prepreg. After the first pressing block 5, the second pressing block 6, the mold protrusion 3, and the mold group 4 are fixed by fasteners, pressure can be applied in one direction by a press, and pressure is applied in other directions by the action of the pressing blocks and fasteners.

[0065] The mold for forming the reinforcing rib of the thermosetting resin-based composite material in the embodiment of the present invention can perform closed-mold net-size molding of the reinforcing rib of the thermosetting resin-based composite material. The mold set and the pressing block used can all adopt metal molds. Compared with the auxiliary molding of the vacuum auxiliary material, soft mold, etc. in the autoclave, the shape accuracy of the prepared material is poor and secondary processing is required. The mold of the present application performs closed-mold net-size molding, and the rib structure produced has good dimensional stability and does not require secondary processing; and the production cost of the reinforcing rib structure is reduced and the production efficiency is improved; closed-mold molding is to use temperature control equipment to heat the mold, without solid The temperature limit is eliminated, and the range of curing resin matrix in closed mold molding process is wider, which broadens the service temperature range of carbon fiber composite I-shaped reinforcement rib structural parts, and is conducive to the wider application of this type of structure in the aerospace field; when the first pressing block and the second pressing block are inserted into the groove, due to the inclination angle set at the top edge of the groove, the insertion of the pressing block has a certain guiding effect and the effect of inclined force, which makes the mold installation operation easier on the one hand, and on the other hand, the force applied by the inclination angle to the pressing block can be decomposed into a horizontal force, under the action of this force, the pressing block presses the side of the mold assembly and the prepreg to further compact the prepreg.

[0066] In some embodiments, the specific structure of the mold set can be adjusted.

[0067] Preferably, if Figure 6 As shown, the reinforcing rib 7 includes a web 71, a flange 72, a first side plate 73 and a second side plate 74; the flange 72 is located at the bottom of the web 71 and is perpendicular to the web 71, the first side plate 73 is arranged at the end of one end of the web 71, and the second side plate 74 is arranged at the end of the other end of the web 71.

[0068] The top of the mold convex block 3 is provided with a molding surface matching the bottom surface of the flange;

[0069] Die set 4 includes:

[0070] The first web plate mold 41 is located on one side above the mold protrusion 3. The bottom and inner side of the first web plate mold 41 are respectively provided with molding surfaces matching the top surface of one side of the flange 72 and the side surface of one side of the web plate 71. The two ends of the first web plate mold 41 are respectively provided with molding surfaces matching the inner side surfaces of the first side plate 73 and the second side plate 74.

[0071] The second web plate mold 42 is located on the other side above the mold protrusion 3. The bottom and inner side of the second web plate mold 42 are respectively provided with molding surfaces matching the other side top surface of the flange 72, the other side side of the web plate 71, and the top surface of the web plate 71. The two ends of the second web plate mold 42 are respectively provided with molding surfaces matching the inner side surfaces of the first side plate 73 and the second side plate 74.

[0072] The first side plate mold 43 is provided with a molding surface matching the outer side surface of the first side plate 73;

[0073] The second side plate mold 44 is provided with a molding surface matching the outer side surface of the second side plate 74;

[0074] The first web plate mold 41 , the second web plate mold 42 , the first pressing block 5 , the second pressing block 6 , the first side plate mold 43 , the second side plate mold 44 , and the mold protrusion 3 are fixed by fasteners.

[0075] Since the closed mold hot pressing process is a one-way pressure transmission (generally in the vertical direction), it is only suitable for the molding of simple structural parts such as "C" and "L" shapes. The thermosetting resin-based composite material reinforcement rib molding mold of the embodiment of the present invention further limits the structure of the mold group used for molding, and the web mold and the mold protrusion are used to press the web side wall of the reinforcement rib and the flange of the reinforcement rib, and the side panel mold and the web mold are used to press the top and bottom surfaces of the side panel, and the pressure block is used to press the side edge of the flange. The molds are combined with fasteners and presses to perform multi-dimensional pressurization to ensure the accuracy of the mold molding of the prepreg.

[0076] Preferably, the first pressing block 5 is connected and fastened to the first web mold 41 by a first fastening screw 8; the second pressing block 6 is connected and fastened to the second web mold 42 by a second fastening screw 9. The pressing blocks are fastened to the corresponding web molds by fastening screws. The first pressing block 5, the first web mold 41, the second web mold 42, and the second pressing block 6 are also connected and fastened by a third fastening screw 10 that penetrates. The pressing blocks and web molds on both sides are further penetrated by screws to ensure the stability of the pressure on the web.

[0077] The first pressing block 5, the mold convex block 3 and the second pressing block 6 are connected and fastened by the penetrating fourth fastening screws 11. After the pressing block and the mold convex block are fixed, the stability of the lateral position of the pressing block can be ensured, and the stability of the pressure application can be ensured.

[0078] The bottom of the first pressing block 5 and the second pressing block 6 are connected and fastened to the bottom of the groove by the fifth fastening screw 12. Thus, the pressing block is fixed to the base, ensuring that the bottom of the web mold exerts pressure on the flange in the longitudinal direction.

[0079] The first side panel mold 43 is connected and fastened to the first pressing block 5 and the second pressing block 6 by the sixth fastening screw 13; the second side panel mold 44 is connected and fastened to the first pressing block 5 and the second pressing block 6 by the seventh fastening screw 14. The side panel mold applies pressure to the side panel of the reinforcing rib.

[0080] The above structures are fixed with fastening screws to ensure the stability of the pressure applied by each structure.

[0081] Preferably, the inclination angle 9 is 1° to 10°.

[0082] Preferably, the stiffener 7 is a negative curvature stiffener; the first web mold 41 includes a first petal 411, a second petal 412 and a third petal 413 arranged in sequence from one end to the other end; the first petal 411 and the second petal 412 are connected by an eighth fastening screw 15; the third petal 413 and the second petal 412 are connected by a ninth fastening screw 16; the second web mold 42 includes a fourth petal 421, a fifth petal 422 and a sixth petal 423 arranged in sequence from one end to the other end; the fourth petal and the fifth petal are connected by a tenth fastening screw 17; the sixth petal and the fifth petal are connected by an eleventh fastening screw 18. For the negative curvature stiffener, its web mold is divided into petals, and the net size forming accuracy of the stiffener structure is achieved through reasonable parting.

[0083] Example 2

[0084] The preparation method of the thermosetting resin-based composite material reinforcement rib closed mold net size molding of this embodiment includes the following steps:

[0085] S1. Using the thermosetting resin-based composite material reinforcement molding mold of Example 1, the thermosetting resin-based prepreg is covered in the mold cavity;

[0086] S2. Pre-curing the thermosetting resin-based prepreg in the cavity so that it is pre-compacted;

[0087] S3. The first pressing block and the second pressing block are respectively arranged on both sides of the mold group and the mold protrusion, and are fastened to the mold group and the mold protrusion, and are pressurized from top to bottom by a press machine, and are heated and cured at the same time.

[0088] At present, the molding method of thermosetting resin-based composite material reinforcement ribs is usually hot-pressed, which is expensive and has high production costs. The auxiliary molding by vacuum auxiliary materials, soft molds, etc. has poor shape accuracy of the prepared materials and requires secondary processing. The preparation method of closed-die net size molding of thermosetting resin-based composite material reinforcement ribs of the embodiment of the present invention uses a mold for thermosetting resin-based composite material reinforcement rib molding to perform closed-die net size molding. The produced reinforcement rib structure has good dimensional stability and does not require secondary processing; and the production cost of the reinforcement rib structure is reduced, and the production efficiency is improved.

[0089] Preferably, step S1 specifically includes:

[0090] S101. Covering the bottom, sides and ends of the first web mold with a thermosetting resin-based prepreg to obtain a first preform having an L-shaped longitudinal section;

[0091] S102. Covering the bottom, sides and ends of the second web mold with a thermosetting resin-based prepreg to obtain a second preform having an L-shaped longitudinal section;

[0092] S103. Arrange the first web plate mold and the second web plate mold on the mold protrusion, assemble the first preform and the second preform, and lay a skin on the joint surface.

[0093] Among them, the reinforcing material of the thermosetting resin-based prepreg is continuous fiber, specifically one or more of carbon fiber, basalt fiber, quartz fiber, and aramid fiber; the resin matrix of the thermosetting resin-based prepreg is one or more of epoxy resin, bismaleimide resin, benzoxazine resin, and phthalonitrile.

[0094] The mass content of the resin matrix in the thermosetting resin-based prepreg is 20% to 43%; the single-layer thickness of the prepreg is 0.02 to 0.35 mm; the content of volatile matter is 2.5% to 5%; the surface density of the reinforcing fiber is 100 to 380 g / m 3 ; The reinforcing material is in the form of at least one of a unidirectional tape structure, plain weave, and twill fabric.

[0095] Preferably, step S1 further includes laying a peelable cloth on the first web mold, the second web mold, the first side plate mold, and the second side plate mold before laying the thermosetting resin-based prepreg in step S1 to control the surface roughness of the reinforcing rib structure and facilitate demoulding. The weight of the peelable cloth is 200-400 g / m 3 , thickness is 0.3~1mm.

[0096] Preferably, in step S1, the thermosetting resin-based prepreg is laid in a quasi-isotropic laying manner of [+45° / 0° / -45° / 90° / -45° / 0° / +45°]n, where n is a natural number.

[0097] Preferably, in step S2, the pre-curing conditions are to increase the temperature to 60°C to 120°C at a heating rate of 60 to 90°C / h; and then keep the temperature at a pressure of 0.3 to 1 MPa for 0.5 to 2 hours.

[0098] Preferably, in step S3, the temperature is raised to 110°C to 280°C at a heating rate of 20 to 80°C / h; and then kept at this temperature for 1 to 6 hours at a pressure of 0.3 to 5 MPa.

[0099] Preferably, step S3 specifically includes:

[0100] S301. The first pressing block and the second pressing block are respectively arranged on the outside of the first web mold and the second web mold, and the first pressing block is connected and fastened to the first web mold by a third fastening screw; the second pressing block is connected and fastened to the second web mold by a fourth fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0101] S302. The first pressing block, the mold protrusion, and the second pressing block are connected and fastened by the first fastening screw passing through; the first pressing block, the first web mold, the second web mold, and the second pressing block are connected and fastened by the seventh fastening screw passing through; the tightening torque of the screw is 15 to 30 N·m;

[0102] S303. Connect and tighten the bottom of the first pressing block and the second pressing block to the bottom of the groove through a second fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0103] S304. Connect and fasten the first side panel mold to the first pressing block and the second pressing block through the fifth fastening screw; connect and fasten the second side panel mold to the first pressing block and the second pressing block through the sixth fastening screw; the tightening torque of the screw is 15 to 30 N·m;

[0104] S305. Use a press to apply pressure from top to bottom while heating and curing.

[0105] Example 3

[0106] The preparation method of the thermosetting resin-based composite material reinforcement rib closed mold net size molding of this embodiment includes the following steps:

[0107] (1) Epoxy resin carbon fiber unidirectional fiber prepreg tape is used, the resin content is 33%, the volatile content is less than 2.5%, and the thickness of the single layer after curing is 0.09-0.1mm.

[0108] (2) Cover the first web plate mold, the second web plate mold, the first side plate mold, and the second side plate mold with a peelable cloth to control the surface roughness of the reinforcing rib structure and facilitate demoulding. The weight of the peelable cloth is 300g / m 3, thickness is 0.5mm.

[0109] (3) The bottom surface, side surfaces and both ends of the first web mold are covered with thermosetting resin-based prepreg to obtain a first preform with an L-shaped longitudinal cross-section; the plying is performed in a quasi-isotropic manner of [+45° / 0° / -45° / 90° / -45° / 0° / +45°]n.

[0110] (4) Laying thermosetting resin-based prepreg on the bottom surface, side surfaces and both ends of the second web mold to obtain a second preform with an L-shaped longitudinal cross-section; the laying is carried out in a quasi-isotropic laying method of [+45° / 0° / -45° / 90° / -45° / 0° / +45°]n.

[0111] (5) The first web mold and the second web mold are arranged on the mold protrusion, the first preform and the second preform are assembled together, and the prepreg of the skin is spread on the joint surface.

[0112] (6) pre-curing the thermosetting resin-based prepreg in the cavity to pre-compact it, and the pre-curing conditions are heating to 90° C. at a heating rate of 80° C. / h; and then keeping the temperature at 0.3 MPa for 1 hour;

[0113] (7) The first pressing block and the second pressing block are respectively arranged on the outside of the first web mold and the second web mold, and the first pressing block is connected and fastened to the first web mold by fastening screws; the second pressing block is connected and fastened to the second web mold by fastening screws; the tightening torque of the screws is 20 N·m;

[0114] (8) Connect and tighten the first pressing block, the mold protrusion, and the second pressing block through the through-fastening screws; connect and tighten the first pressing block, the first web mold, the second web mold, and the second pressing block through the through-fastening screws; the tightening torque of the screws is 20 N·m;

[0115] (9) Connect and tighten the bottom of the first pressing block and the second pressing block to the bottom of the groove by means of fastening screws; the tightening torque of the screws is 20 N·m;

[0116] (10) The first side panel mold is connected and fastened with the first pressing block and the second pressing block by fastening screws; the second side panel mold is connected and fastened with the first pressing block and the second pressing block by fastening screws; the tightening torque of the screws is 20 N·m.

[0117] (11) A press is used to apply pressure from top to bottom at a pressure of 3 MPa, and the temperature is raised to 200°C at a heating rate of 50°C / h for curing; then, the temperature is kept at 2 MPa for 4 h.

[0118] Example 4

[0119] The preparation method of closed-die net-size molding of thermosetting resin-based composite material reinforcement ribs in this embodiment is different from that in Embodiment 3 in that the tightening torque of each screw is 15 N·m.

[0120] Example 5

[0121] The preparation method of the thermosetting resin-based composite material reinforcement rib closed-die net size molding of this embodiment is different from that of Embodiment 3 in that the tightening torque of each screw is 30 N·m.

[0122] Comparative Example

[0123] The preparation method of the thermosetting resin-based composite reinforcement ribs in this comparative example adopts autoclave molding. Specifically, the multi-dimensional pressurization design is realized by utilizing the filling gas in the autoclave, and "C"-shaped and "L"-shaped structural component preforms are laid on the surface of the mold male mold, and then the "C"-shaped and "L"-shaped structural component preforms are combined into I-shaped structural component preforms through tooling, and then the skin is covered, and then the skin surface of the preform is covered with vacuum bags, adhesive absorbing materials, porous films and other auxiliary materials. The male mold is mostly a soft mold that expands under heat to form an "I"-shaped beam or "T"-shaped rib structure. The resin curing molding pressure in the web area.

[0124] The properties of the thermosetting resin-based composite material reinforcement bars obtained in Examples 3, 4 and 5 of the present invention were tested, and the test results are shown in Table 1 below.

[0125] Table 1 Performance of test plates with furnace samples

[0126]

[0127] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A mold for forming a thermosetting resin-based composite material reinforcement rib, characterized in that: include: A base; the base is provided with a groove; A mold protrusion, wherein the mold protrusion is arranged in the groove; A mold set, the mold set is located above the mold convex block, the mold set is provided with an inner cavity with an open bottom, and the inner cavity of the mold set is assembled with the upper surface of the mold convex block to form a cavity suitable for forming the reinforcing rib; a first pressing block, the first pressing block being located at one side of the mold set and the mold protrusion and being insertable into the gap between the groove and the mold protrusion; when the first pressing block is inserted into the gap between the groove and the mold protrusion, the first pressing block applies pressure to the side of the mold set through the action of the groove on the first pressing block; the groove is provided with an inclination at the top edge where the first pressing block is inserted; a second pressing block, the second pressing block is located on the other side of the mold set and the mold protrusion, and can be inserted into the gap between the groove and the mold protrusion; when the second pressing block is inserted into the gap between the groove and the mold protrusion, the second pressing block applies pressure to the side of the mold set through the action of the groove on the second pressing block; the groove is provided with an inclination at the top edge where the first pressing block is inserted; The first pressing block, the second pressing block, the mold protrusion, and the mold set are fixed by fasteners.

2. The mold for forming a thermosetting resin-based composite material reinforcement rib according to claim 1, characterized in that: The reinforcing rib comprises a web, a flange, a first side plate and a second side plate; the flange is located at the bottom of the web and is perpendicular to the web, the first side plate is arranged at an end of one end of the web, and the second side plate is arranged at an end of the other end of the web; The top of the mold convex block is provided with a molding surface matching the bottom surface of the flange; The mold set comprises: A first web plate mold is located on one side above the mold protrusion, and the bottom and inner side of the first web plate mold are respectively provided with molding surfaces matching the top surface of one side of the flange and the side surface of one side of the web, and both ends of the first web plate mold are respectively provided with molding surfaces matching the inner side surfaces of the first side plate and the second side plate; A second web plate mold is located on the other side above the mold protrusion, and the bottom and inner side of the second web plate mold are respectively provided with molding surfaces matching the other side top surface of the flange, the other side side of the web plate, and the top surface of the web plate, and both ends of the second web plate mold are respectively provided with molding surfaces matching the inner side surfaces of the first side plate and the second side plate; A first side panel mold, provided with a molding surface matching the outer side surface of the first side panel; A second side panel mold, provided with a molding surface matching the outer side surface of the second side panel; The first web plate mold, the second web plate mold, the first pressing block, the second pressing block, the first side plate mold, the second side plate mold, and the mold protrusion are fixed by fasteners.

3. The mold for forming a thermosetting resin-based composite material reinforcement rib according to claim 2, characterized in that: The first pressing block is connected and fastened to the first web mold by a first fastening screw; the second pressing block is connected and fastened to the second web mold by a second fastening screw; the first pressing block, the first web mold, the second web mold, and the second pressing block are also connected and fastened by a third fastening screw that penetrates through them; The first pressing block, the mold convex block, and the second pressing block are connected and fastened by a fourth fastening screw that penetrates through the pressing block; The bottom of the first pressing block and the bottom of the second pressing block are connected and fastened to the bottom of the groove by a fifth fastening screw; The first side panel mold is connected and fastened to the first pressing block and the second pressing block via a sixth fastening screw; the second side panel mold is connected and fastened to the first pressing block and the second pressing block via a seventh fastening screw.

4. The mold for forming a thermosetting resin-based composite material reinforcement rib according to claim 1, characterized in that: The inclination angle is 1° to 10°.

5. The mold for forming a thermosetting resin-based composite material reinforcement rib according to claim 4, characterized in that: The reinforcing ribs are negative curvature reinforcing ribs; The first web mold includes a first petal, a second petal and a third petal arranged in sequence from one end to the other end; the first petal is connected to the second petal by an eighth fastening screw; the third petal is connected to the second petal by a ninth fastening screw; The second web mold includes a fourth petal, a fifth petal and a sixth petal arranged in sequence from one end to the other end; the fourth petal is connected to the fifth petal by a tenth fastening screw; the sixth petal is connected to the fifth petal by an eleventh fastening screw.

6. A preparation method for closed-die net-size molding of thermosetting resin-based composite reinforcement ribs, characterized in that: The following steps are involved: S1. Using the thermosetting resin-based composite material reinforcement rib forming mold according to any one of claims 1 to 5, the thermosetting resin-based prepreg is spread in the mold cavity of the mold; S2. Precuring the thermosetting resin-based prepreg in the cavity so that it is pre-compacted; S3. The first pressing block and the second pressing block are respectively arranged on both sides of the mold set and the mold protrusion, and are fastened to the mold set and the mold protrusion, and are pressurized from top to bottom by a press machine, and are cured by heating at the same time.

7. The preparation method according to claim 6, characterized in that: Step S1 specifically includes: S101. Covering the bottom, sides and ends of the first web mold with a thermosetting resin-based prepreg to obtain a first preform having an L-shaped longitudinal section; S102. Covering the bottom, sides and ends of the second web mold with a thermosetting resin-based prepreg to obtain a second preform having an L-shaped longitudinal section; S103. Arrange the first web mold and the second web mold on the mold protrusion, splice the first preform and the second preform, and lay a skin on the splicing surface.

8. The preparation method according to claim 6, characterized in that: In step S2, the pre-curing conditions are to heat the material to 60°C to 120°C at a heating rate of 60 to 90°C / h; and then keep the temperature at a pressure of 0.3 to 1 MPa for 0.5 to 2 hours; In step S3, the temperature is raised to 110°C to 280°C at a heating rate of 20 to 80°C / h for curing; and then kept at a pressure of 0.3 to 5 MPa for 1 to 6 hours.

9. The preparation method according to claim 6, characterized in that: Step S3 specifically includes: S301. The first pressing block and the second pressing block are respectively arranged on the outside of the first web mold and the second web mold, and the first pressing block is connected and fastened to the first web mold by a third fastening screw; the second pressing block is connected and fastened to the second web mold by a fourth fastening screw; the tightening torque of the screw is 15 to 30 N·m; S302. The first pressing block, the mold protrusion, and the second pressing block are connected and fastened by a first through-going fastening screw; the first pressing block, the first web mold, the second web mold, and the second pressing block are connected and fastened by a seventh through-going fastening screw; the tightening torque of the screw is 15 to 30 N·m; S303. Connect and tighten the bottom of the first pressing block and the second pressing block to the bottom of the groove through a second fastening screw; the tightening torque of the screw is 15 to 30 N·m; S304. Connect and fasten the first side panel mold to the first pressing block and the second pressing block through the fifth fastening screw; connect and fasten the second side panel mold to the first pressing block and the second pressing block through the sixth fastening screw; the tightening torque of the screw is 15 to 30 N·m; S305. Use a press to apply pressure from top to bottom while heating and curing.

10. The preparation method according to claim 6, characterized in that: In step S1, the thermosetting resin-based prepreg is laid in a quasi-isotropic laying mode of [+45° / 0° / -45° / 90° / -45° / 0° / +45°]n, where n is a natural number; The reinforcing fibers in the thermosetting resin-based prepreg are continuous fibers; the mass content of the resin in the thermosetting resin-based prepreg is 20-43%; the single-layer thickness of the prepreg is 0.02-0.35 mm; the content of volatiles is 2.5-5%; the surface density of the reinforcing fibers is 100-380 g / m 3 ; The reinforcing material is in the form of at least one of a unidirectional tape structure, plain weave, and twill fabric.

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