Built-in carbon fiber reinforced cylindrical shell, machining mold and machining method

Abstract

The invention relates to a built-in carbon fiber reinforced cylindrical shell, a machining die and a machining method.The built-in carbon fiber reinforced cylindrical shell comprises a cylindrical shell body and reinforcing ribs located on the inner side of the cylindrical shell body, the cylindrical shell body is made of aluminum alloy and integrally formed through a spinning technology, and the reinforcing ribs are arranged on the inner side of the cylindrical shell body in a crossed mode and made of carbon fibers; and the winding shaft is fixedly connected to the inner side of the barrel shell body through wet winding. On the premise that the stability performance and the bearing performance of the reinforced cylindrical shell structure are guaranteed, aluminum alloy reinforcing ribs are replaced with carbon fiber winding reinforcing ribs, and the purpose of overall weight reduction is achieved; meanwhile, the carbon fiber winding reinforcing rib is processed by a winding machine through a wet winding process, the carbon fiber winding reinforcing rib and the barrel shell are combined and stable through high-temperature curing, and the carbon fiber winding reinforcing rib produced through the method is uniform and continuous and has better bearing performance and lighter weight.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing main load-bearing components of aerospace structures, and in particular to a built-in carbon fiber reinforced cylinder shell, a processing mold and a processing method. Background Art

[0002] Thin-walled cylindrical shell structures have high specific stiffness and high specific strength. In the field of aerospace, grid-reinforced cylindrical shell structures are widely used as the main connection and load-bearing structure. Under the action of compressive loads, instability is the main form of failure. During the rocket launch process, the thin-walled cylindrical shell structure is subjected to huge axial compressive loads due to overload, and is prone to buckling instability, resulting in structural failure. Therefore, the ultimate bearing capacity of the thin-walled cylindrical shell structure under axial compression conditions is a key assessment indicator in the design process of aerospace structures such as launch vehicles. Under axial compression conditions, the main failure mode of the reinforced cylindrical shell structure is buckling instability, including overall structural instability, local skin instability, local rib instability and material plastic instability.

[0003] In order to ensure the load-bearing performance, the overall thickness of the skin and the thickness of the reinforcement will be increased, but this will increase the overall weight of the structure. Due to its design characteristics, aerospace equipment often pursues extreme weight reduction. The existing structure usually uses aluminum alloy or other alloy steel materials and is processed by forging, extrusion or machining. The above processes have different problems such as long production cycle and difficulty in ensuring the accuracy of the ribs, so further improvement is needed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a cylindrical shell with built-in carbon fiber reinforcement, a processing mold and a processing method, which reduce the weight of the entire structure while ensuring its load-bearing performance, and the carbon fiber reinforcement ribs are uniform and continuous, and the processing difficulty is relatively low.

[0005] The present invention is achieved through the following technical solutions:

[0006] A cylindrical shell with built-in carbon fiber reinforcement comprises a cylindrical shell body and reinforcing ribs located inside the cylindrical shell body. The cylindrical shell body is made of aluminum alloy and is integrally formed by a spinning process. The reinforcing ribs are cross-arranged on the inner side of the cylindrical shell body and are made of carbon fiber and are fixedly connected to the inner side of the cylindrical shell body.

[0007] According to the above technical solution, preferably, the reinforcing ribs are cross-arranged on the inner side of the shell body, are made of carbon fiber, and are fixedly connected to the inner side of the shell body by one or more methods of riveting, bonding, laser welding or wet winding.

[0008] According to the above technical solution, preferably, the shell body includes a skin, an upper end frame and a lower end frame located at both ends of the skin, and the reinforcing ribs are placed on the inner side of the skin by wet winding.

[0009] According to the above technical solution, preferably, the reinforcing ribs form a cross-arranged mesh structure on the inner surface of the skin, and the circumferential direction thereof is divided into clockwise and counterclockwise directions, with a total of 6 nodes in the circumferential direction.

[0010] The present application also discloses a processing mold for a built-in carbon fiber reinforced cylindrical shell, which is used to manufacture the above-mentioned built-in carbon fiber reinforced cylindrical shell, including an upper mold, a lower mold and a core mold located between the upper mold and the lower mold, and a plurality of fiber fixing blocks are fixedly connected to the outer side of the core mold. The fiber fixing blocks are diamond-shaped blocks with curvatures and are installed on the outer side of the core mold, and a mesh structure that is compatible with the shape of the reinforcing ribs is formed between the fiber fixing blocks.

[0011] According to the above technical solution, preferably, the core mold includes an inner core mold and an outer core mold, and each of the fiber fixing blocks is installed and arranged on the outer side of the outer core mold.

[0012] According to the above technical solution, preferably, a plurality of limiting holes are arranged between the inner core mold and the outer core mold along the circumferential direction, and the inner core mold and the outer core mold are fixed at the limiting holes by limiting bolts and limiting nuts.

[0013] According to the above technical solution, preferably, each of the fiber fixing blocks is installed on the outside of the outer core mold by means of a hexagon socket bolt.

[0014] The present application also discloses a method for processing a cylindrical shell with built-in carbon fiber reinforcement, based on the above-mentioned processing mold for a cylindrical shell with built-in carbon fiber reinforcement, comprising the following steps:

[0015] S1. The mandrel is fixed on the winding device, a release agent is applied to the interval gaps between the fiber stop blocks, and the carbon fibers are wound along the interval gaps between the fiber fixing blocks;

[0016] S2. The shell body is integrally formed by spinning process;

[0017] S3. The shell body is mounted on the outside of the core mold, and the shell body and the core mold with carbon fiber are fastened together by the upper mold and the lower mold, and placed in a curing oven for curing;

[0018] S4. The upper mold, the lower mold, the core mold and the fiber fixing block are disassembled in sequence to form a built-in carbon fiber grid reinforced cylinder shell.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a carbon fiber reinforced thermoplastic composite grid reinforced cylinder shell and a processing mold and a processing method thereof, which can replace aluminum alloy reinforcing ribs with carbon fiber wound reinforcing ribs on the premise of ensuring the structural stability and load-bearing performance of the reinforced cylinder shell, thereby achieving the purpose of overall weight reduction; at the same time, the carbon fiber wound reinforcing ribs are processed by a winding machine using a wet winding process, and the carbon fiber wound reinforcing ribs are combined and stabilized with the cylinder shell through high-temperature curing. The carbon fiber wound reinforcing ribs produced by this method are uniform and continuous, and have better load-bearing performance and lighter weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the built-in carbon fiber reinforced cylinder shell in the present invention.

[0022] Figure 2 It is a three-dimensional structural schematic diagram of the cylinder shell body in the present invention.

[0023] Figure 3 It is a schematic diagram of the three-dimensional structure of the reinforcing rib part in the present invention.

[0024] Figure 4 It is a three-dimensional structural schematic diagram of the core mold part in the present invention.

[0025] Figure 5 It is a side structural schematic diagram of the core mold part in the present invention.

[0026] Figure 6 It is a three-dimensional structural schematic diagram of the inner core mold and the outer core mold part in the present invention.

[0027] Figure 7 It is a schematic diagram of the main structure of the inner core mold and the outer core mold in the present invention.

[0028] Figure 8 It is a three-dimensional structural schematic diagram of a processing mold for a built-in carbon fiber reinforced cylinder shell in the present invention.

[0029] Fig. 9 It is a schematic diagram of the three-dimensional structure of the fiber fixing block part of the present invention.

[0030] In the figure: 1. Shell body; 2. Reinforcement ribs; 3. Core mold; 4. Upper mold; 5. Lower mold;

[0031] 101, upper end frame; 102, skin; 103, lower end frame;

[0032] 301, inner core mold; 302, outer core mold; 303, limiting bolt; 304, fiber fixing block; 305, hexagon socket bolt; 306, limiting nut; 307, limiting hole. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiment. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the invention.

[0034] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the invention.

[0035] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Embodiment 1: As shown in the figure, the present invention discloses a built-in carbon fiber reinforced cylinder shell, including a cylinder shell body 1 and a reinforcing rib 2 located on the inner side of the cylinder shell body 1, wherein the cylinder shell body 1 includes a skin 102, an upper end frame 101 and a lower end frame 103 located at both ends of the skin 102, the cylinder shell body 1 is made of aluminum alloy, and is integrally formed by a spinning process, the reinforcing rib 2 is cross-arranged on the inner side of the skin 102 in the cylinder shell body 1, and is made of carbon fiber material, and is fixedly connected to the inner side of the cylinder shell body 1, specifically, in this example, the reinforcing rib 2 forms a cross-arranged mesh structure on the inner surface of the skin 102, and its circumferential direction is divided into clockwise and counterclockwise directions, and there are a total of 6 nodes in the circumferential direction. In addition, in this example, the carbon fiber reinforcing rib 2 can be formed by a winding curing process, and the carbon fiber reinforcing rib 2 can also be fixed and combined with the skin 102 by riveting, bonding, laser welding or other combining methods.

[0037] Example 2: The present application also discloses a processing mold for a built-in carbon fiber reinforced cylindrical shell, which is used to manufacture the above-mentioned built-in carbon fiber reinforced cylindrical shell, including an upper mold 4, a lower mold 5 and a core mold 3 located between the upper mold 4 and the lower mold 5, and a plurality of fiber fixing blocks 304 are fixedly connected to the outer side of the core mold. The fiber fixing blocks 304 are diamond-shaped blocks with arcs, which are installed on the outer side of the core mold, and a mesh structure that is compatible with the shape of the reinforcing ribs 2 is formed between each of the fiber fixing blocks 304.

[0038] The core mold 3 includes an inner core mold 301 and an outer core mold 302, and each of the fiber fixing blocks 304 is installed and arranged on the outside of the outer core mold 302. A plurality of limiting holes 307 are arranged between the inner core mold 301 and the outer core mold 302 along the circumferential direction. The inner core mold 301 and the outer core mold 302 are fixed at the limiting holes 307 by limiting bolts 303 and limiting nuts 306, so as to ensure that the inner core mold 301 and the outer core mold 302 are fixed and rotate synchronously during the winding process. Each of the fiber fixing blocks 304 is installed on the outside of the outer core mold 302 by hexagon socket bolts 305. After the fiber fixing blocks 304 are installed, a release agent is applied in the interval gaps between the fiber limiting blocks to facilitate the demoulding steps of the fiber fixing blocks 304 and the outer core mold 302 after the fiber winding curing process.

[0039] Embodiment 3: The present application also discloses a method for processing a cylindrical shell with built-in carbon fiber reinforcement, based on the above-mentioned processing mold for a cylindrical shell with built-in carbon fiber reinforcement, comprising the following steps:

[0040] S1. The mandrel is fixed on the winding device, a release agent is applied to the interval gaps of each of the fiber limiting blocks, and the carbon fibers are wound along the interval gaps between the fiber fixing blocks 304;

[0041] S2. The shell body 1 is integrally formed by spinning process;

[0042] S3. The shell body 1 is mounted on the outside of the core mold, and the shell body 1 is fastened together with the core mold with carbon fiber through the upper mold 4 and the lower mold 5, and placed in a curing oven for high temperature curing;

[0043] S4. Sequentially disassemble the upper mold 4, the lower mold 5, the limit key, the inner core mold 301, the inner hexagon, the outer core mold 302, and finally disassemble the fiber fixing block 304 to form a built-in carbon fiber grid reinforced cylinder shell.

[0044] The upper end frame, skin and lower end frame of the cylinder shell body in the present invention are made of aluminum alloy and processed by a spinning process. Reinforcement ribs intersecting at a certain angle are placed on the inner side of the skin, and the built-in reinforcement ribs are made of carbon fiber. The carbon fiber is wound on the core mold by a fiber winding machine using a wet winding method. Then, the mold is installed on the cylinder shell structure, and the cylinder shell structure is covered with the core mold wrapped with carbon fiber for overall curing. Finally, after the curing is completed, the mold is removed, the core mold is unloaded, and the entire production process of the built-in carbon fiber grid reinforced cylinder shell structure is completed. The carbon fiber grid reinforced cylinder shell structure manufactured by the above processing method reduces the weight of the entire structure while ensuring its load-bearing performance, and the carbon fiber reinforcement ribs are uniform and continuous, and the processing difficulty is relatively low.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A cylindrical shell with internal carbon fiber reinforcement, characterized in that: The invention comprises a cylinder shell body (1) and a reinforcing rib (2) located inside the cylinder shell body (1); the cylinder shell body (1) is made of aluminum alloy and is integrally formed by a spinning process. The reinforcing ribs (2) are cross-arranged on the inner side of the cylindrical shell body (1), are made of carbon fiber material, and are fixedly connected to the inner side of the cylindrical shell body (1).

2. According to claim 1, a cylindrical shell with internal carbon fiber reinforcement, characterized in that: The reinforcing ribs (2) are cross-arranged on the inner side of the shell body (1), are made of carbon fiber material, and are fixedly connected to the inner side of the shell body (1) by one or more methods of riveting, bonding, laser welding or wet winding.

3. According to claim 2, a cylindrical shell with internal carbon fiber reinforcement, characterized in that: The shell body (1) comprises a skin (102), an upper end frame (101) and a lower end frame (103) located at both ends of the skin (102), and the reinforcing ribs (2) are placed inside the skin (102) by wet winding.

4. According to claim 3, a cylindrical shell with internal carbon fiber reinforcement, characterized in that: The reinforcing ribs (2) form a cross-arranged mesh structure on the inner surface of the skin (102), and the circumferential direction thereof is divided into a clockwise direction and a counterclockwise direction, with a total of 6 nodes in the circumferential direction.

5. A processing mold for a built-in carbon fiber reinforced cylindrical shell, used for manufacturing a built-in carbon fiber reinforced cylindrical shell as claimed in claim 3, characterized in that: It comprises an upper mold (4), a lower mold (5) and a core mold (3) located between the upper mold (4) and the lower mold (5). A plurality of fiber fixing blocks (304) are fixedly connected to the outside of the core mold (3); the fiber fixing blocks (304) are diamond-shaped blocks with arcs and are installed on the outside of the core mold; a mesh structure matching the shape of the reinforcing ribs (2) is formed between the fiber fixing blocks (304).

6. A processing mold for a cylindrical shell with built-in carbon fiber reinforcement according to claim 5, characterized in that: The core mold (3) comprises an inner core mold (301) and an outer core mold (302), and each of the fiber fixing blocks (304) is installed and arranged on the outer side of the outer core mold (302).

7. A processing mold for a cylindrical shell with built-in carbon fiber reinforcement according to claim 6, characterized in that: A plurality of limiting holes (307) are arranged between the inner core mold (301) and the outer core mold (302) along the circumferential direction, and the inner core mold (301) and the outer core mold (302) are fixed at the limiting holes (307) by limiting bolts (303) and limiting nuts (306).

8. A processing mold for a cylindrical shell with built-in carbon fiber reinforcement according to claim 6 or 7, characterized in that: Each of the fiber fixing blocks (304) is mounted on the outside of the outer core mold (302) via a hexagon socket bolt (305).

9. A method for processing a cylindrical shell with built-in carbon fiber reinforcement, based on the processing mold for a cylindrical shell with built-in carbon fiber reinforcement as claimed in claim 5, characterized in that: The steps include: S1. Fixing the core mold on the winding device, applying a release agent in the interval gaps of each of the fiber limiting blocks, and winding the carbon fiber along the interval gaps between the fiber fixing blocks (304); S2. The shell body (1) is integrally formed by a spinning process; S3. The shell body (1) is mounted on the outside of the core mold, and the shell body (1) is fastened together with the core mold with carbon fiber through the upper mold (4) and the lower mold (5), and placed in a curing oven for curing; S4. The upper mold (4), the lower mold (5), the core mold and the fiber fixing block (304) are disassembled in sequence to form a built-in carbon fiber grid reinforced cylinder shell.

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