A composite material reinforced bulkhead and its manufacturing mold and molding method

Abstract

The present invention discloses a composite reinforced bulkhead, a manufacturing mold for the composite reinforced bulkhead and a molding method for the composite reinforced bulkhead, and relates to the technical field of bulkhead structure equipment. The reinforced bulkhead comprises a frame, a foam core and reinforcing ribs, the frame is formed by a composite material ply, and a reinforcing layer is provided in the composite material ply. The manufacturing mold for the composite reinforced bulkhead comprises a chassis, an outer mold and a base, the chassis is provided with a raised component consistent with the shape of the through hole at the position of the through hole of the reinforced bulkhead. The molding method for the composite reinforced bulkhead comprises the overall plying of the composite material and the plying of the reinforcing layer, and the final plying exceeding the pre-plying part and removing the isolation film, so as to complete the overall plying of the reinforced bulkhead. The advantages of the present invention are that the local strength and rigidity of the bulkhead are enhanced, the integrity is strong, and the problems of insufficient connection strength with aircraft components and heavy bulkhead weight are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material bulkhead preparation, and in particular relates to a composite material reinforced bulkhead, a manufacturing mold for the composite material reinforced bulkhead, and a manufacturing method for the composite material reinforced bulkhead. Background Art

[0002] Bulkheads are generally used as the main force transmission and load-bearing structures of aircraft, pods, missile bodies and other product structures. The strength and rigidity of bulkheads are important guarantees to prevent cabin failure. Traditional bulkheads are usually composed of structures such as flanges, webs, and stiffeners. Most of them are metal structures such as steel, aluminum alloy, and magnesium alloy. Affected by the process and the properties of the materials themselves, metal bulkheads have problems such as heavy weight, low load-bearing efficiency, and poor corrosion resistance. In addition, bulkheads need to be connected to aircraft, pods, missile bodies and other products through connecting mechanisms. The local connecting mechanisms of bulkheads lack sufficient strength and rigidity, which affects the overall strength and service life of the bulkheads, and poses a great hidden danger to the safety of key products such as aircraft, pods, and missile bodies. Summary of the invention

[0003] The main purpose of the present invention is to provide a reinforced bulkhead made of composite material to solve the problem that the local connection mechanism of the bulkhead in the prior art lacks sufficient strength and rigidity, which affects the overall strength and service life of the bulkhead.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows:

[0005] A composite material reinforced bulkhead comprises a frame body, a foam core and reinforcing ribs, wherein the foam core is filled in the frame body, the reinforcing ribs are supported in the frame body, the frame body is composed of composite material plies, and a reinforcing layer is arranged in the composite material plies.

[0006] Further, according to the stress conditions, the inner surface of the frame is convex at the reinforcement layer position, and a notch is provided on the reinforcement rib, and the notch cooperates with the convex reinforcement layer, so that the partition frame is further reinforced locally and can better withstand external forces.

[0007] Furthermore, the reinforcing rib is L-shaped and arranged in the foam core, including a supporting portion and a bending portion connected thereto, the supporting portion being arranged on the upper and lower surfaces of the frame, and the bending portion being embedded in the foam core and supported on the surface of the frame, so that the foam layers can be better bonded together, thereby increasing the overall performance of the partition frame and the pressure-bearing effect.

[0008] Optionally, there are four reinforcing ribs, and the foam core is formed by splicing four core units. The reinforcing ribs are arranged between two adjacent core units. By arranging multiple reinforcing ribs, multiple notches on the reinforcing ribs are formed to cooperate with the raised reinforcing layer, so that the overall structural performance and local stress effect of the bulkhead are better, and the number of local connecting mechanisms can also be increased.

[0009] Optionally, the reinforced bulkhead is provided with a polygonal through hole, and a circular through hole is provided outside the polygonal through hole, and the through hole can effectively reduce the weight of the bulkhead.

[0010] The present invention also provides a manufacturing mold for a composite material reinforced bulkhead, comprising:

[0011] The chassis, outer mold and base are provided with positioning pin holes, the outer mold and the chassis are connected together by bolts, and the chassis is provided with polygonal protrusions and circular protrusions that are respectively consistent with the polygonal through hole and the circular through hole. The polygonal protrusions and the circular protrusions are both hollow structures with bottom openings, which can ensure that the reinforced bulkhead can be evenly heated during curing, thereby ensuring the curing quality of the reinforced bulkhead.

[0012] The present invention also provides a method for forming a composite material reinforced bulkhead, comprising the following steps:

[0013] S1: Laying a layer of integral prepreg ply in the outer mold and between the polygonal protrusions, and cutting the prepreg ply on the upper part of the circular protrusions, the purpose of the cutting is to lay the prepreg ply in sequence and cover the installed foam core and reinforcement ribs in the end;

[0014] S2: The position of the reinforcement layer is located by laser projection. On the basis of the above-mentioned ply, two layers of prepreg ply are separately laid at the position of the reinforcement layer, and the bag is made for pre-compaction;

[0015] S3: Lay two more layers of overall prepreg. Add a separation film between the layers beyond the pre-laid layer. Adding a separation film can effectively prevent the layers from sticking together.

[0016] S4: On the basis of the above-mentioned ply, two layers of prepreg ply are laid separately at the position of the reinforcement layer again, and finally a layer of overall prepreg ply is laid, and the bag is made and pre-compacted;

[0017] S5: coating the foam core and the reinforcing rib with a layer of adhesive film, then filling the foam core and placing the reinforcing rib, the notch and the convex reinforcing layer cooperate, thus achieving a local reinforcement effect;

[0018] S6: finally, the isolation film is removed and the plies exceeding the pre-ply portion are laid out in sequence to complete the overall prepreg ply of the reinforced bulkhead;

[0019] S7: After bagging the entire reinforced bulkhead body, evacuate the bag and then solidify it. After solidification, remove the outer mold and take out the reinforced bulkhead.

[0020] In the ply laying process, for individual plies that are not longer than the pre-laid part, there is a staggered distance between the overlapping areas of the layers. The staggered distance can effectively prevent the problem of insufficient bonding strength between the joints of the individual plies, which affects the structural properties of the overall ply laying.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] The present invention provides a composite material reinforced bulkhead, which has the advantages of light weight, high structural efficiency, high strength, corrosion resistance, etc., and through holes are arranged in the frame to reduce weight, which can reduce weight by 30-40% compared with traditional bulkheads. At the same time, a reinforcement layer is arranged locally in the bulkhead, and reinforcement ribs are installed in conjunction with the use, which enhances the rigidity and strength of the local bulkhead, and solves the problem of insufficient strength and rigidity of the local connection mechanism.

[0023] The present invention provides a manufacturing mold for a composite material reinforced bulkhead, comprising a chassis, an outer mold and a base, wherein the chassis is provided with a polygonal protrusion and a circular protrusion having the same shape as the through hole at the position of the reinforced bulkhead through hole. The polygonal protrusion and the circular protrusion are both hollow structures with bottom openings, which can ensure that the reinforced bulkhead can be evenly heated during curing, thereby ensuring the curing quality of the reinforced bulkhead.

[0024] The present invention also provides a molding method for a composite reinforced bulkhead, wherein the prepreg is laid on the frame of the reinforced frame by using a mold of the reinforced frame, and local thickening is performed separately at the reinforcement layer. Except for the separate thickening at the reinforcement layer, the other layers are integral prepreg layers, and the bags are vacuumed and compacted after laying, so that the overall structure is good. In the laying, the individual layers that are not longer than the pre-laid part are staggered between the overlapped areas of the layers, and the staggered distance can effectively prevent the insufficient bonding strength between the joints of the individual layers, thereby improving the overall structure of the layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0026] Figure 1 It is a schematic diagram of the reinforcement bulkhead;

[0027] Figure 2 It is the exploded view of the reinforcement bulkhead;

[0028] Figure 3 It is a diagram of strengthening the partition frame;

[0029] Figure 4 yes Figure 3 Middle AA section view and magnified view of the strengthening layer;

[0030] Figure 5 It is a schematic diagram of L-shaped reinforcement;

[0031] Figure 6 is a schematic diagram of the foam core;

[0032] Figure 7 is a schematic diagram of a molding die;

[0033] Figure 8 It is a chassis schematic diagram;

[0034] Fig. 9 yes Figure 8 Middle AA section view;

[0035] Fig.10 It is a schematic diagram of the outer mold;

[0036] Fig.11 This is a schematic diagram of the cutout of the prepreg layer on the circular protrusion in the reinforcement frame

[0037] Fig.12 This is a schematic diagram of the reinforced frame ply

[0038] Description of reference numerals:

[0039] 1 frame, 2 polygonal through hole, 3 circular through hole, 1-1 reinforcement rib, 1-1-1 notch, 1-1-2 bending part, 1-1-3 support part, 1-2 groove, 1-2-1 local reinforcement, 4 foam core, 5-1 lifting ring, 5-2 base, 5-3 chassis, 5-4 outer mold, 5-5 polygonal protrusion, 5-6 circular protrusion, 5-7 positioning pin hole, 5-8 bolt, 5-9 target hole, 6-1 slot, 6-2 reference hole, 7-1 isolation membrane, 7-2 overall prepreg layer, 7-3 reinforcement layer DETAILED DESCRIPTION

[0040] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0041] Embodiment 1:

[0042] Figure 1 As shown, Example 1 of the present application provides a composite material reinforced bulkhead. Figure 1-Figure 6 The reinforced bulkhead shown,

[0043] It includes a frame 1, a foam core 4 and a reinforcing rib 1-1, wherein the foam core 4 is filled in the frame 1, the reinforcing rib 1-1 is supported in the frame 1, and the frame 1 is composed of a composite material ply, wherein a reinforcing layer 7-3 is arranged in the composite material ply. The reinforcing layer 7-3 on the inner surface of the frame 1 is in a convex shape, and a notch 1-1-1 is arranged on the reinforcing rib 1-1, and the notch 1-1-1 cooperates with the convex reinforcing layer 7-3. The present invention solves the problem that the local structure of the bulkhead needs to be connected to products such as aircraft, and needs to meet the stress characteristics of the local stiffness and strength of the bulkhead through the above scheme, further increases the role of the connecting mechanism with products such as aircraft in stable connection, and solves the problem that the local part of the frame lacks sufficient strength and stiffness.

[0044] like Figure 5 As shown, the reinforcing rib 1-1 is L-shaped, including a supporting portion 1-1-3 and a bending portion 1-1-2 connected thereto, wherein the supporting portion 1-1-3 is supported and arranged between the upper and lower surfaces of the frame 1, and the bending portion 1-1-2 is embedded in the foam core 4 and supported on the surface of the frame 1. Such a mechanism can not only make the upper and lower surfaces of the frame 1 have the function of bearing pressure, but also can make the reinforcing rib 1-1 and the foam core 4 better connected together, achieving an integral effect.

[0045] Furthermore, there are four reinforcing ribs 1-1, and the foam core 4 is formed by splicing four core units, and an L-shaped reinforcing rib 1-1 is set between two adjacent core units. The L-shaped reinforcing rib 1-1 is a sheet structure, and a plurality of reinforcing parts can be formed by the cooperation of the notch 1-1-1 set on the reinforcing rib 1-1 and the reinforcing layer 7-3 in the frame 1. Such a plurality of reinforcing parts not only makes the frame 1 more solid in its entirety and in parts, but also makes it more convenient to connect with products such as aircraft. Figure 2 As shown, the reinforcing rib 1-1 cooperates with the reinforcing layer 7-3, and a groove 1-2 is formed on the surface of the foam core 4 to cooperate with the reinforcing layer 7-3. A connecting component is arranged at the reinforcing layer position of the frame 1 to facilitate the connection of the reinforcing bulkhead with products such as aircraft. Figure 4 As shown, the local reinforcement 1-2-1 is to strengthen the internal reinforcement structure of the bulkhead to enhance the internal strength of the bulkhead.

[0046] Furthermore, in order to reduce the weight of the bulkhead, the foam core material 4 is filled in the reinforced bulkhead, and the frame 1 has a polygonal through hole 2 and four circular through holes 3. The frame 1 is made of composite material, preferably carbon fiber material. The reinforced bulkhead of the present invention is an integrally formed overall design, light in weight and strong in structure, which can maximize the structural efficiency of the bulkhead, and can reduce 30% to 40% of the weight compared with the traditional bulkhead structure, and its comprehensive performance index is excellent.

[0047] Embodiment 2:

[0048] Figure 7-10 As shown, Example 2 of the present application provides a manufacturing mold for a composite material reinforced bulkhead, including a base 5-2 and a chassis 5-3. The base 5-2 is located at the lower part of the four corners of the chassis 5-3. The base 5-2 can be adjusted to adjust the level of the chassis 5-3. Lifting rings 5-1 are provided at the four corners of the chassis 5-3 to facilitate the lifting and movement of the entire mold. The mold is provided with polygonal protrusions 5-5 and circular protrusions 5-6, and the shapes of the protrusions are consistent with the shapes of the polygonal through holes 2 and the circular through holes 3 of the bulkhead. Positioning pin holes 5-7 are provided on the outer mold 5-4 and the chassis 5-3 to locate the corresponding positions of the outer mold 5-4 and the base 5-3, and then connected with bolts 5-8. The connecting holes of the positioning pin holes 5-7 and the bolts 5-8 are distributed circumferentially along the outer mold 5-4, and are all blind holes, so as to ensure the sealing of the reinforced bulkhead during curing, thereby ensuring the structural quality. As shown Figure 7 As shown, there are three outer molds 5-4, which are spliced ​​and installed on the chassis 5-3 to form the overall shape of the bulkhead. In addition, a target hole 5-9 is set on the chassis 5-3, which is used to place the target of laser projection when manually laying the local reinforcement position of the bulkhead to locate the position of the reinforcement layer 7-3. A reference hole 6-2 is set on the chassis 5-3 for mold machining and detection, which has high precision and can be convenient for subsequent mold maintenance.

[0049] Furthermore, a groove 6-1 is provided on the polygonal protrusion 5-5 to make it a hollow structure with an open bottom, so as to ensure that the inside and outside of the reinforced bulkhead can be heated evenly during curing, thereby ensuring the curing quality of the reinforced bulkhead.

[0050] Embodiment 3:

[0051] Embodiment 3 of the present application provides a method for forming a composite material reinforced bulkhead, which enhances the overall structural performance of the bulkhead and the stress characteristics of the local stiffness and strength by laying the reinforcement layer 7-3. Specifically, the method comprises the following steps: Fig.11 As shown, a layer of integral prepreg ply 7-2 is laid inside the outer mold 5-4 and between the polygonal raised parts 5-5, and the prepreg ply is cut on the upper part of the circular raised parts 5-6. The prepreg ply in the cut is finally filled with the foam core 4 and the reinforcing ribs 1-1 and then covered and laid layer by layer; Fig.12As shown, the position of the reinforcing layer 7-3 is located by laser projection. On the basis of the above-mentioned ply, two layers of prepreg ply are separately laid at the position of the reinforcing layer 7-3, and the bag is pre-compacted. The vacuuming of the bag has a more obvious compaction effect; then two layers of integral prepreg ply 7-2 are laid, and an isolation film 7-1 is added between the layers for the part exceeding the pre-ply. Here, the part exceeding the pre-ply can be understood as the part exceeding the height of the polygonal protrusion 5-5. Adding the isolation film 7-1 can effectively prevent the ply of the exceeding part from sticking together; on the basis of the above-mentioned ply, two layers of prepreg ply are separately laid at the position of the reinforcing layer 7-3 again. Prepreg plying, and finally laying a layer of overall prepreg ply 7-2, and pre-compacting it by bagging; a layer of adhesive film is coated on the surface of the foam core 4 and the reinforcing rib 1-1, and then the foam core 4 is filled and the reinforcing rib 1-1 is placed, and the notch 1-1-1 and the raised reinforcing layer 7-3 cooperate to form local reinforcement; finally, the isolation film 7-1 is removed and the plies exceeding the pre-laid part are laid in sequence to complete the overall prepreg ply 7-2 of the reinforced bulkhead; the reinforced bulkhead body is bagged as a whole, vacuumed, and then cured. After the curing is completed, the outer mold 5-4 is removed and the reinforced bulkhead is taken out.

[0052] It should be noted that in the ply, the part exceeding the pre-ply may have different reserved lengths during plying. If the reserved length is insufficient, a separate ply is required. The overlap areas between the layers are staggered. The staggered distance can effectively prevent the joints between the separate plies from being insufficiently bonded, and improve the overall structural properties of the ply. In this way, auxiliary materials such as isolation film, demoulding cloth, breathable felt and vacuum bag film are laid on the surface of the mold and the product in sequence to ensure complete coverage without bridging or unreality. The vacuum bag film is sealed with a sealing strip, and a vacuum nozzle is left on the vacuum bag for vacuuming. The vacuum degree is ≥900mbar, and the vacuum pressure drop within 5 minutes shall not exceed 17mbar. Finally, it is placed in an autoclave for curing. After curing, the temperature is lowered, and the cured product and mold are taken out of the autoclave, the auxiliary materials are removed, the bolts 5-8 between the outer mold 5-4 and the chassis 5-3 are removed, and the outer mold 5-4 is removed, thereby demolding and taking out the reinforced bulkhead with a clean edge.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0054] In addition, it should be understood that although the present specification is described according to embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that those skilled in the art can understand.

Claims

1. A method for forming a composite material reinforced bulkhead, characterized in that: The composite material reinforced bulkhead comprises a frame body, a foam core and reinforcing ribs, wherein the foam core is filled in the frame body, the reinforcing ribs are supported in the frame body, the frame body is composed of a composite material ply, and a reinforcing layer is arranged in the composite material ply; the reinforced bulkhead is provided with a polygonal through hole, and a circular through hole is arranged outside the polygonal through hole; The composite material reinforced bulkhead is manufactured by a mold, the mold includes a chassis, an outer mold and a base, the outer mold and the chassis are provided with positioning pin holes, the outer mold and the chassis are connected together by bolts, the reinforced bulkhead is provided with a polygonal through hole, and a circular through hole is provided outside the polygonal through hole; the chassis is provided with a polygonal protrusion and a circular protrusion respectively having the same shape as the polygonal through hole and the circular through hole; the polygonal protrusion and the circular protrusion are both hollow structures with bottom openings; The molding method of the composite material reinforced bulkhead comprises the following steps: S1: Laying a layer of integral prepreg ply between the outer mold and the polygonal protrusion, and cutting the prepreg ply on the upper part of the circular protrusion; S2: The position of the reinforcement layer is located by laser projection. On the basis of the above-mentioned ply, two layers of prepreg ply are separately laid at the position of the reinforcement layer, and the bag is made for pre-compaction; S3: Lay two more layers of integral prepreg, and add a separation film between the layers beyond the pre-laid layer; S4: On the basis of the above-mentioned ply, two layers of prepreg ply are laid separately at the position of the reinforcement layer again, and finally a layer of overall prepreg ply is laid, and the bag is made and pre-compacted; S5: coating the foam core and the reinforcing rib with a layer of adhesive film, then filling the foam core and placing the reinforcing rib, and matching the reinforcing rib notch with the convex reinforcing layer; S6: finally, the isolation film is removed and the layers exceeding the pre-laid layer are laid out in sequence to complete the overall prepreg laying of the reinforced bulkhead; S7: After bagging the reinforced bulkhead as a whole, vacuum is drawn, and then the bag is cured. After the curing is completed, the outer mold is removed and the reinforced bulkhead is taken out.

2. The method for forming a composite material reinforced bulkhead according to claim 1, characterized in that: The reinforcing layer on the inner surface of the frame is in a convex shape, and a notch is provided on the reinforcing rib, and the notch cooperates with the convex reinforcing layer.

3. The method for forming a composite material reinforced bulkhead according to claim 2, characterized in that: The reinforcing rib is L-shaped and includes a supporting portion and a bending portion connected thereto. The supporting portion is supported and arranged between the upper and lower surfaces of the frame body. The bending portion is embedded in the foam core and supported on the surface of the frame body.

4. The method for forming a composite material reinforced bulkhead according to claim 3, characterized in that: There are four reinforcing ribs, and the foam core is formed by splicing four core units. An L-shaped reinforcing rib is arranged between two adjacent core units.

5. The method for forming a composite material reinforced bulkhead according to claim 1, characterized in that: If the length of the layer that exceeds the pre-laid layer is insufficient, a separate layer shall be laid with staggered distances between the overlapping areas of the layers.

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