Manufacturing method of internally reinforced carbon fiber cylinder section

Abstract

The invention discloses a manufacturing method of an internally reinforced carbon fiber cylinder section, which comprises the following steps: respectively paving prepregs on concave arc surfaces of two half dies to preset thickness to form pre-paving layers; the two half molds are spliced oppositely, and the connected edges of the pre-laying layers on the two sides are in lap joint and solidified to form a primary cylinder wall; stringer assemblies are installed on the half molds outside the two axial ends of the primary cylinder wall, and three or more stringer assemblies are arranged along the circumference of the primary cylinder wall; a plurality of grooves are formed in the side faces, facing the primary cylinder wall, of the stringer assemblies in the length direction. Foam strips are laid in the circumferential direction of the inner wall face of the primary cylinder, and each foam strip is arranged in the corresponding groove in the stringer assembly in a penetrating mode; paving a plurality of circles of foam strips along the axial direction of the primary cylinder wall at intervals; the stringer assembly is dismantled; the prepreg continues to be laid on the surface of the primary cylinder wall and the surface of the foam strip to the preset thickness, and the prepreg laid on the foam strip protrudes to form a rib; curing to form a cylinder section with ribs inside; therefore, the completely-integrated internally-reinforced cylinder section is formed, and the structural performance of the internally-reinforced cylinder section is effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber molding technology, and in particular to a method for manufacturing an internally reinforced carbon fiber cylindrical section. Background Technology

[0002] The outer shell of existing deep-sea exploration equipment is generally made of 316L stainless steel. Due to the high density of steel, the overall equipment is relatively heavy. The limited size of the equipment results in a small effective load-bearing capacity, which cannot accommodate more exploration instruments. Existing equipment can only operate in shallow waters and relatively mild sea conditions.

[0003] Carbon fiber composites, as a lightweight material with superior comprehensive performance, can be used as the shell material for deep-sea exploration equipment. This reduces weight while increasing the compressive strength of the shell and improving the effective load-bearing capacity of the equipment, enabling the exploration equipment to conduct exploration operations in harsher sea conditions and deeper waters.

[0004] Existing deep-sea exploration equipment typically has a pressure-resistant cylindrical shell structure to evenly distribute water pressure. As a conventional method to improve the rigidity of the shell, reinforcing ribs are usually installed on the inner or outer side of the shell.

[0005] In the existing technology, for cylindrical structures made of carbon fiber, the reinforcing ribs and the cylinder are usually formed separately and then bonded to the cylinder by adhesive bonding. However, the existing pure adhesive bonding cylinder and reinforcing ribs do not have a continuous fiber layer, which affects the torsional load-bearing performance of the cylinder and is not suitable for the molding and use of the shell of deep-sea exploration equipment. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a method for manufacturing a structurally sound internally reinforced carbon fiber cylindrical section, thereby forming a completely integrated internally reinforced cylindrical section that greatly ensures the overall structural performance of the section, making it particularly suitable as the outer shell of deep-sea exploration equipment.

[0007] The technical solution adopted in this invention is as follows: A method for manufacturing an internally reinforced carbon fiber cylindrical segment includes the following steps: Prepreg is laid on the concave arc surfaces of the two half-molds to a predetermined thickness to form a pre-lay layer; Two half-molds are joined together facing each other, and the edges of the pre-laid layers on both sides are overlapped and cured to form the primary cylinder wall. Long stringer assemblies are installed on the semi-molds at both ends of the primary cylinder wall. Three or more sets of long stringer assemblies are arranged along the circumference of the primary cylinder wall. Each set of long stringer assemblies facing the primary cylinder wall has multiple grooves along its length on its side. Lay foam strips along the circumferential direction of the inner wall of the primary cylinder, with each foam strip passing through the corresponding groove on the stringer assembly; lay multiple rings of foam strips at intervals along the axial direction of the primary cylinder wall; remove the stringer assembly; Prepreg is continued to be laid on the primary cylinder wall and the surface of the foam strip to the preset thickness, and the prepreg protrusions at the foam strip form ribs; The solidification process forms an internally reinforced cylindrical section.

[0008] As a further improvement to the above technical solution: Before curing to form the primary cylinder wall, a peelable fabric is laid on the surface of the overlapping pre-laid layer, and then the whole thing is vacuum-sealed and placed in a thermostatic jar for vacuum and pressure curing to form the primary cylinder wall.

[0009] The stringer assembly includes two end supports and a stringer extending between the two end supports. The two end supports are respectively locked onto the half-molds on the outer sides of the axial ends of the primary cylinder wall. The stringer is trussed on the inner side of the primary cylinder wall. A groove is formed on the side of the stringer facing the primary cylinder wall along the length direction.

[0010] The foam strips are pre-treated before installation, including cleaning, drying, and applying adhesive film.

[0011] After the foam strips are laid and the stringer components are removed, a layer of adhesive film is applied to the primary cylinder wall and the surface of the foam strips, and then vacuum cold pressing is performed before the prepreg is applied.

[0012] Locking holes for installing stringer components are provided on the half-mold located at both ends of the primary cylinder wall. Positioning components are installed through the locking holes and extend to the inside of the primary cylinder wall. The positioning components limit the position of the inserts laid on the inner wall of the primary cylinder wall.

[0013] The surface of the insert facing the primary cylinder wall is pretreated before installation. The pretreatment includes sandblasting, cleaning, drying, and applying adhesive film.

[0014] The positioning component includes a base, which is locked into the locking hole of the half mold by a fastening component. The base extends toward the inner side of the primary cylinder wall with a positioning part, and the positioning part has a positioning hole for the insert to be fitted. The insert extends toward both sides with side wings located between the positioning part and the primary cylinder wall.

[0015] When laying prepreg, the starting points of the prepreg in adjacent layers are staggered; vacuum cold pressing is performed every four layers; and vacuum hot compaction is performed every 2mm thickness.

[0016] When continuing to lay prepreg on the primary cylinder wall and foam strip surface, the axial laying deviation angle of the prepreg is ≯±3°, the overlap width between adjacent prepregs in the circumferential direction is 20-25mm, and the overlap positions of adjacent layers are staggered in the circumferential direction.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention employs two half-molds to lay prepreg on each half, assembling them into a primary cylindrical wall. Foam strips are then systematically laid at predetermined positions on the inner wall of the primary cylindrical wall using a stringer assembly. Prepreg is then laid on the primary cylindrical wall and the foam strips to a predetermined thickness. After curing, an internally reinforced cylindrical segment is formed, thus constituting a completely integrated internally reinforced cylindrical segment. This ensures the structural integration between the cylindrical wall and the inner reinforcing ribs, greatly guaranteeing the overall structural performance of the cylindrical segment and ensuring its overall structural rigidity, torsional resistance, and pressure resistance. It is particularly suitable as the outer shell of deep-sea exploration equipment. The present invention also includes the following advantages: The long string assembly positions the foam strips, and the positioning assembly positions the inserts, effectively ensuring the reliability and consistency of the positions of the ribs and inserts relative to the cylinder segment. Furthermore, the long string assembly and the positioning assembly can share the same set of fastening components for assembly relative to the half mold, which simplifies the overall structure of the auxiliary mold while ensuring the forming of the cylinder segment, making it easier to operate and use. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of laying a pre-layer on a half-mold in the first step of the present invention.

[0019] Figure 2 This is a schematic diagram of assembling the stringer assembly in the third step of the present invention.

[0020] Figure 3 This is a schematic diagram of the assembly of the stringer assembly and foam strip relative to the half mold of the present invention.

[0021] Figure 4 This is a schematic diagram of assembling the positioning component in the third step of the present invention.

[0022] Figure 5 This is a schematic diagram of the assembly of the positioning component of the present invention relative to the half-mold.

[0023] Figure 6 This is a schematic diagram of the assembled foam strips and inserts according to the present invention.

[0024] Figure 7 This is a schematic diagram of the fourth step of the present invention, after the prepreg is laid.

[0025] Figure 8 This is a schematic diagram of the structure of the cylindrical section of the present invention.

[0026] Figure 9 for Figure 8 A magnified view of a portion of point A in the middle.

[0027] Figure 10 This is a schematic diagram of the manufacturing method of the present invention.

[0028] Figure 11 The time-temperature-pressure curve is shown for the formation of the primary cylinder wall in this invention.

[0029] The components include: 1. Pre-lay layer; 2. Foam strip; 3. Inlay; 301. Side fins; 4. Ribs; 11. Primary cylinder wall; 10. Half mold; 20. Long stringer assembly; 30. Sealing strip; 40. Long bolt; 50. Fastening assembly; 60. Positioning assembly; 101. Locking hole; 21. Support; 22. Truss; 221. Groove; 61. Base; 62. Positioning part; 621. Positioning hole. Detailed Implementation

[0030] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0031] like Figure 10 As shown, a method for manufacturing an internally reinforced carbon fiber cylindrical segment according to this embodiment includes the following steps: Step 1: Apply prepreg to the pre-set thickness on the concave arc surfaces of the two half-molds 10, forming pre-lay layer 1, as shown. Figure 1 As shown.

[0032] When laying prepreg, the starting points of the prepreg in adjacent layers are staggered, for example, by 20mm; vacuum cold pressing is performed every four layers; and vacuum hot compaction is performed every time the thickness reaches 2mm.

[0033] In this embodiment, referring to the conventional method in existing prepreg laying, vacuum bags are used for cold pressing. In one embodiment, the vacuum pressure is ≥95kPa and the vacuuming time is ≥5min each time.

[0034] In this embodiment, referring to the conventional method in existing prepreg laying, a vacuum hot compaction is performed using an autoclave. For example, in one embodiment, a vacuum bag is used on the outside, with the pressure inside the bag ≤ -90kPa and the pressure inside the autoclave ≥ 0.3MPa.

[0035] Of course, in actual operation, just like conventional prepreg laying, the half mold 10 needs to be cleaned, purified, and coated with release agent.

[0036] Step 2: Join the two half molds 10 together facing each other, and overlap the edges of the pre-laid layers 1 on both sides to form the primary cylinder wall 11.

[0037] In this embodiment, a sealing strip 30 is provided at the junction of the two half molds 10 to ensure that the two half molds 10 are stably assembled.

[0038] Before curing to form the primary cylinder wall 11, a peelable fabric is laid on the surface of the overlapping pre-laid layer 1, and then the whole thing is vacuum-sealed and placed in a thermostatic jar for vacuum and pressure curing to form the primary cylinder wall 11.

[0039] In practice, vacuum pressure curing can be performed by considering the characteristics of the cylinder section and referring to existing prepreg curing methods. In one embodiment, vacuum pressure curing can be used. Figure 11 The curing process was carried out using the time-temperature-pressure curve shown. Heating and pressurization began at 30℃, with a heating rate of 1℃ / min and a pressurization rate of 0.06MPa / min. The pressure was maintained at 0.6MPa until the end of the second stage of heat preservation. The first stage of heat preservation began at 80℃ and lasted for 30 minutes. The temperature was then increased to 130℃ for the second stage of heat preservation, which lasted for 2 hours. After the heat preservation was completed, the temperature and pressure were reduced. The product was removed from the container at atmospheric pressure and cooled to 60℃, completing the curing process.

[0040] In actual operation, bolts and other fasteners can be used to lock and secure the two half molds 10 that are joined together. At the same time, long bolts 40 can be installed at the joint of the two half molds 10 to facilitate the hoisting and transfer of the mold.

[0041] Step 3: After the primary cylinder wall 11 is formed, the reinforcing bars 4 and / or the inserts 3 can be formed according to the requirements of the cylinder section.

[0042] In this embodiment, the orderly laying of foam strips 2 can be achieved using the stringer assembly 20, thereby facilitating the orderly formation of integrated ribs 4 at predetermined positions on the primary cylinder wall 11. Specifically: Long stringer assemblies 20 are installed on the semi-molds 10 at both ends of the primary cylindrical wall 11. Three or more sets of long stringer assemblies 20 are arranged along the circumference of the primary cylindrical wall 11. Each set of long stringer assemblies 20 facing the primary cylindrical wall 11 has multiple grooves 221 opened on its side along the length direction.

[0043] Foam strips 2 are laid along the circumferential direction of the inner wall surface of the primary cylinder wall 11, with each foam strip 2 passing through the corresponding groove 221 on the stringer assembly 20; multiple rings of foam strips 2 are laid at intervals along the axial direction of the primary cylinder wall 11, such as... Figure 2 As shown; dismantle stringer assembly 20.

[0044] like Figure 3 As shown, the stringer assembly 20 includes two end supports 21 and a stringer 22 extending between the two end supports 21. The two end supports 21 are respectively locked onto the half mold 10 on the outer side of the two axial ends of the primary cylinder wall 11. The stringer 22 is trussed on the inner side of the primary cylinder wall 11. The side of the stringer 22 facing the primary cylinder wall 11 has a groove 221 along the length direction.

[0045] The foam strip 2 is pre-treated before installation. The pre-treatment includes cleaning, drying, and applying adhesive film. In one embodiment, the drying temperature is 100°C and the drying time is more than 4 hours.

[0046] In actual operation, interlocking and matching concave-convex structures can be set at the beginning and end of the foam strip 2 in the same ring direction. While being laid on the inner wall surface of the primary cylinder wall 11, the concave-convex structures ensure reliable end-to-end connection of the foam strip 2 in the same ring direction.

[0047] After laying the foam strip 2 and removing the stringer assembly 20, a layer of adhesive film is laid on the surface of the primary cylinder wall 11 and the foam strip 2, and vacuum cold pressing is performed before the prepreg is laid.

[0048] In this embodiment, the positioning component 60 can be used to orderly lay the insert 3, so as to help to orderly embed the insert 3 at the preset position of the primary cylinder wall 11.

[0049] A locking hole 101 for installing the stringer assembly 20 is provided on the outer half-mold 10 located at both axial ends of the primary cylinder wall 11. A positioning assembly 60 is installed through the locking hole 101, extending to the inner side of the primary cylinder wall 11. The positioning assembly 60 limits the position of the insert 3 attached to the inner wall of the primary cylinder wall 11, thus fixing the insert 3 relative to the primary cylinder wall 11 in a preset position. Figure 4 As shown.

[0050] The surface of the insert 3 facing the primary cylinder wall 11 is pretreated before installation. The pretreatment includes sandblasting, cleaning, drying and applying adhesive film.

[0051] like Figure 5 As shown, the positioning component 60 includes a base 61, which is locked into the locking hole 101 of the half mold 10 by the fastening component 50. The base 61 extends into the inner side of the primary cylinder wall 11 with a positioning part 62. The positioning part 62 is provided with a positioning hole 621 for the insert 3 to be fitted. The insert 3 extends to both sides with side wings 301 located between the positioning part 62 and the primary cylinder wall 11. The side wings 301 effectively increase the laying area between the insert 3 and the primary cylinder wall 11, ensuring the reliability of the laying.

[0052] In actual operation, the insert 3 can be first placed at the positioning hole 621 of the positioning component 60, and then the positioning component 60 can be installed on the primary cylinder wall 11 to determine the laying position of the insert 3 relative to the primary cylinder wall 11. With the help of the positioning component 60 and the primary cylinder wall 11, the insert 3 can be reliably laid on the primary cylinder wall 11.

[0053] like Figure 6 The diagram shown is a schematic of the process after foam strips 2 and inserts 3 are laid on the inner side of the primary cylinder wall 11.

[0054] The stringer assembly 20 positions the foam strip 2, and the positioning assembly 60 positions the insert 3, effectively ensuring the reliability and consistency of the positions of the ribs 4 and inserts 3 relative to the cylinder segment. Furthermore, the stringer assembly 20 and the positioning assembly 60 can share the same set of fastening assemblies 50 for assembly relative to the half mold 10, which effectively simplifies the overall structure of the auxiliary mold while ensuring the forming of the cylinder segment, making it easier to operate and use.

[0055] In this embodiment, the installation positions of the stringer assembly 20, the positioning assembly 60, and the half-mold 10 are all located outside the cylindrical section, so as to achieve reliable and convenient assembly with the half-mold 10 without affecting the forming of the cylindrical section.

[0056] In this embodiment, the fastening component 50 includes a positioning pin and a positioning screw, which are used for the reliable installation of the stringer component 20 and the positioning component 60 relative to the half mold 10.

[0057] In actual operation, there is no specific order for laying foam strips 2 and inserts 3 on the primary cylinder wall 11; they are independent of each other and can be set according to the actual design of the cylinder section.

[0058] Step 4: Continue to lay prepreg on the primary cylinder wall 11 and foam strip 2 to the preset thickness. The prepreg protrusions laid on the foam strip 2 form ribs 4, such as... Figure 7 As shown.

[0059] When laying prepreg, the starting points of the prepreg in adjacent layers are staggered; vacuum cold pressing is performed every four layers; and vacuum hot compaction is performed every 2mm thickness.

[0060] When continuing to lay prepreg on the surface of the primary cylinder wall 11 and foam strip 2, the axial laying deviation angle of the prepreg is ≯±3°, the overlap width between adjacent prepregs in the circumferential direction is 20-25mm, and the overlap positions of adjacent layers are staggered in the circumferential direction, for example, staggered at 45°.

[0061] Step 5: Curing to form an internally reinforced cylinder section; the corresponding curing method can refer to the curing of the primary cylinder wall 11 in Step 2.

[0062] exist Figure 8 and Figure 9 The embodiment shown is a schematic diagram of a cylindrical section with five reinforcing ribs formed internally. It can be seen that after the foam strip 2 is laid on the primary cylindrical wall 11, the prepreg laid on top will form raised ribs 4 at the foam strip 2. Thus, the prepreg laid on the primary cylindrical wall 11 and the foam strip 2 forms a completely integrated structure of the inner wall of the cylindrical section, effectively ensuring the integrated structure of the ribs 4 on the cylindrical section.

[0063] Step 6: Demolding; Use a pry bar to pry open the mold opening point of the assembled half mold 10 and remove the cylinder section from the mold.

[0064] Step 7: Machining; Existing machining equipment can be used to process the pre-set positions of the cylinder section, such as cutting, drilling, milling, etc., so that the cylinder section can be assembled with the object.

[0065] In practice, structural adhesive resin can be used to seal the edges of the cylinder section.

[0066] In this embodiment, two half-molds 10 are used to lay prepreg on each half and assemble them into a primary cylinder wall 11. Foam strips 2 are laid in an orderly manner at a preset position on the inner wall surface of the primary cylinder wall 11 with the help of the stringer assembly 20. Then, prepreg is laid on the surface of the primary cylinder wall 11 and the foam strips 2 to a preset thickness. After curing, an internally reinforced cylinder segment is formed, thus constituting a completely integrated internally reinforced cylinder segment, which in particular ensures the structural integration between the cylinder wall and the inner reinforcing ribs 4.

[0067] This invention ensures the structural integration between the cylinder wall and the inner reinforcing ribs, greatly guaranteeing the overall structural performance of the cylinder section and ensuring its overall structural rigidity, torsion resistance, and pressure resistance. It is especially suitable as the outer shell of deep-sea exploration equipment.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0069] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method of manufacturing an internally stiffened carbon fibre barrel section, characterised by: It comprises the following steps: Two half-molds (10) are respectively laid on the inner concave arc surface of the two half-molds (10) to a predetermined thickness to form a pre-laid layer (1); The two half-molds (10) are combined towards each other, the two pre-laid layers (1) are overlapped at the joint edges, and the primary barrel wall (11) is formed by curing; The stringer assembly (20) is installed on the half-mold (10) outside the axial ends of the primary barrel wall (11), and the stringer assembly (20) is arranged in three groups or more along the circumference of the primary barrel wall (11); a plurality of grooves (221) are formed on the side of each group of stringer assemblies (20) facing the primary barrel wall (11) along the length direction; Foam strips (2) are laid along the circumferential direction of the inner wall surface of the primary barrel wall (11), and a single foam strip (2) is arranged in the corresponding groove (221) of the stringer assembly (20); a plurality of rings of foam strips (2) are laid at intervals along the axial direction of the primary barrel wall (11); and the stringer assembly (20) is removed; Prepreg is continuously laid on the surface of the primary barrel wall (11) and the foam strips (2) to a predetermined thickness, and the protruding prepreg at the foam strips (2) forms the rib strips (4); An internally reinforced barrel section is formed by curing.

2. A method of manufacturing an internally reinforced carbon fibre cylinder segment as claimed in claim 1, characterised in that: Before the primary barrel wall (11) is formed by curing, a peelable cloth is laid on the surface of the overlapped pre-laid layer (1), and then a vacuum bag is formed and placed in a hot press tank for vacuumizing and pressurizing curing to form the primary barrel wall (11).

3. A method of manufacturing an internally reinforced carbon fibre cylinder segment as claimed in claim 1 characterised in that: The stringer assembly (20) comprises two end supports (21) and a stringer (22) extending between the two end supports (21), the two end supports (21) are respectively locked on the half-molds (10) outside the axial ends of the primary barrel wall (11), and the stringer (22) is arranged inside the primary barrel wall (11); grooves (221) are formed on the side of the stringer (22) facing the primary barrel wall (11) along the length direction.

4. The method of manufacturing an internally reinforced carbon fiber cylinder segment of claim 1, wherein: The foam strips (2) are pretreated before being laid, and the pretreatment includes cleaning, drying, and attaching a film.

5. The method of manufacturing an internally reinforced carbon fiber cylinder segment of claim 1, wherein: After the foam strips (2) are laid and the stringer assembly (20) is removed, a film is laid on the surface of the primary barrel wall (11) and the foam strips (2) as a whole, and vacuumizing and cold pressing are performed, and then the prepreg is laid.

6. A method of manufacturing an internally reinforced carbon fiber cylinder segment as defined in claim 1, wherein: Locking holes (101) for installing the stringer assembly (20) are formed on the half-molds (10) outside the axial ends of the primary barrel wall (11), a positioning assembly (60) is installed through the locking holes (101), the positioning assembly (60) extends to the inside of the primary barrel wall (11), and the inlay (3) laid on the inner wall of the primary barrel wall (11) is limited by the positioning assembly (60).

7. A method of manufacturing an internally stiffened carbon fibre barrel section as claimed in claim 6, characterised by: The surface of the inlay (3) facing the primary barrel wall (11) is pretreated before being laid, and the pretreatment includes sandblasting, cleaning, drying, and attaching a film.

8. A method of manufacturing an internally stiffened carbon fibre barrel section as claimed in claim 6, characterised by: The positioning assembly (60) comprises a base (61), the base (61) is locked on the locking hole (101) of the half-mold (10) through a fastening assembly (50), the base (61) extends towards the inside of the primary barrel wall (11) and has a positioning part (62), the positioning part (62) has positioning holes (621) for the inlay (3), and the inlay (3) extends towards the two sides and has side fins (301) between the positioning part (62) and the primary barrel wall (11).

9. The method of manufacturing an internally reinforced carbon fiber cylinder segment of claim 1, wherein: In the process of laying up the prepreg, the starting points of the prepreg in the adjacent layers are staggered; vacuum cold pressing is carried out once every four layers; and vacuum hot compaction is carried out once when the thickness reaches 2mm.

10. A method of manufacturing an internally stiffened carbon fibre barrel section as claimed in claim 9, characterised by: In the process of laying up the prepreg on the surface of the primary cylinder wall (11) and the foam strip (2), the deviation angle of the prepreg in the axial direction is ≯±3°, the overlap width between the adjacent prepregs in the circumferential direction is 20-25mm, and the overlap positions of the adjacent layers are staggered along the circumferential direction.

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