Composite material barrel with inner wall groove and forming method of composite material barrel

Abstract

The invention discloses a composite material cylinder with inner wall grooves, the composite material cylinder sequentially comprises an outer layer, a middle layer and an inner layer from outside to inside, and the middle layer is provided with a spacing section protruding from the inner layer to the outer layer; the outer layer and the inner layer are concentrically arranged, the inner peripheral surface of the middle layer is matched with the outer peripheral surface of the inner layer in shape, and the outer peripheral surface of the middle layer is matched with the inner peripheral surface of the outer layer in shape; the outer layer is made of a fiber winding composite material, the inner layer is made of fiber cloth prepreg, the middle layer comprises a foam profile, the foam profile serves as a framework and is embedded with lattice blocks, reinforcing ribs are arranged on the two sides of the interval section, and the reinforcing ribs are formed by segmented splicing. By adopting the foam sandwich structure and adopting the dot matrix blocks to reinforce the middle foam layer in the middle layer, product deformation caused by an asymmetric special-shaped cross section is effectively reduced, the overall pressure resistance of the foam sandwich layer is improved, the product strength is guaranteed, and meanwhile the requirement for light weight of the product is met.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material cylinders, and more specifically, relates to a composite material cylinder with inner wall grooves and a molding method thereof. Background Art

[0002] In order to ensure that the ballistic missile launch tube has sufficient strength, service life and good reliability, the reliability requirements of the launch tube are very strict. If a ballistic missile launch tube fails, it is extremely dangerous. Therefore, how to determine the state of the ballistic missile launch tube and determine the launch reliability of the launch tube is of great practical significance for the launch safety of the ballistic missile. With the improvement of the structure of the launch tube, a launch tube mold is prepared according to the launch tube, and multiple grooves arranged along the length of the launch tube are opened at intervals on the outer wall of the launch tube mold. However, this structure has high requirements for the overall pressure resistance when in use.

[0003] After searching, CN117002035A discloses a composite launch tube and a preparation method thereof, wherein a launch tube mold is prepared according to the launch tube, a plurality of grooves arranged along the length of the launch tube are opened on the outer wall of the launch tube mold at circumferential intervals, and a release agent is applied on the outer surface of the launch tube mold; a high-silica glass fiber plain cloth impregnated with phenolic resin is laid tightly on the launch tube mold to form an erosion-resistant layer; prefabricated foam is filled in the erosion-resistant layer located in the groove until the height of the prefabricated foam is flush with the erosion-resistant layer on both sides of the groove; unidirectional carbon fibers are wound layer by layer on the erosion-resistant layer and the prefabricated foam to form a reinforcement layer; the launch tube is put into a curing furnace, heated and cured to form, and then taken out and separated from the launch tube mold to obtain a composite launch tube; the technical problem that the barrel and the guide rail are formed separately during the preparation of the launch tube, and integrated molding cannot be achieved, which causes difficulty in demolding the launch tube.

[0004] CN107314707A discloses a composite missile launch tube and a preparation method thereof, focusing on the improvement of composite materials. The tube body is composed of all-composite materials, and the characteristics of glass fiber reinforced materials, such as high strength, good toughness but insufficient stiffness, and carbon fiber reinforced materials, such as high strength, good stiffness but insufficient toughness, are utilized to make up for their shortcomings, and the weight is significantly reduced, effectively meeting the requirements of increasingly complex launch environments.

[0005] CN110524913A discloses an integrated molding method of a composite material launch tube foam sandwich structure, comprising: an inner structure layer; an outer structure layer; a plurality of groups of annular ribs, which are arranged between the inner structure layer and the outer structure layer along the axial interval of the inner structure layer; wherein each group of annular ribs comprises: a first annular rib, which comprises a first annular rib matrix and a first annular rib body; a second annular rib, which is arranged at intervals from the first annular rib, and the second annular rib comprises a second annular rib matrix and a second annular rib body; and a plurality of reinforcement areas, which are arranged in a circumferential direction along the inner structure layer; the two ends of the reinforcement area are respectively connected with the first annular rib and the second annular rib; wherein the axial cross-sections of the first annular rib matrix and the second annular rib matrix are both trapezoidal, and the bottom surface of the trapezoid is connected with the inner structure layer; a foam filling layer, which is arranged between the inner structure layer and the outer structure layer, and is located in the space outside the first annular rib, the second annular rib and the reinforcement area. The method focuses on the arrangement of the reinforcement ribs, and is difficult to prepare.

[0006] Moreover, the above-mentioned composite material launch tubes cannot meet the requirements of composite material launch tubes with special-shaped cross-sections and inner wall grooves. How to design a launch tube suitable for inner wall grooves to improve the overall compressive resistance has great practical significance and economic value. Summary of the invention

[0007] In view of the deficiencies in the above-mentioned prior art, the present invention provides a lightweight composite material cylinder with a special-shaped cross-section and an inner wall groove. By adopting a foam sandwich structure and reinforcing the middle foam layer with lattice blocks, the product deformation caused by the asymmetric special-shaped cross-section is effectively reduced, the overall compressive resistance of the foam sandwich layer is improved, and the strength of the product is ensured while meeting the demand for lightweight product.

[0008] The present invention is achieved through the following technical solutions: Disclosed is a composite material cylinder with inner wall grooves, which comprises an outer layer, an intermediate layer and an inner layer from the outside to the inside, wherein a spacing section is provided at the intermediate layer, protruding from the inner layer to the outer layer; the outer layer and the inner layer are arranged concentrically, and the inner circumference of the intermediate layer is in accordance with the outer circumference of the inner layer, and the outer circumference of the intermediate layer is in accordance with the inner circumference of the outer layer; the outer layer is a fiber-wound composite material, the inner layer is a fiber cloth prepreg, the intermediate layer comprises a foam profile, and the foam profile is used as a skeleton and has dot array blocks embedded therein; reinforcing ribs are provided on both sides of the spacing section, and the reinforcing ribs are formed by segmented splicing to prevent the reinforcing ribs from deforming, so that the segments are connected into a whole.

[0009] The composite material cylinder with inner wall grooves of the present invention is innovative in structure. According to the stress characteristics of the cylinder with inner wall grooves, a foam profile is arranged in the middle layer with a dot matrix block structure embedded in it to enhance the compressive strength of the foam in the middle layer and improve the overall deformation resistance of the composite material cylinder. At the same time, reinforcing ribs are arranged on both sides of the interval section to effectively reduce the deformation of the special-section cylinder under the action of internal pressure. The overall strength of the cylinder is increased without increasing the weight, thereby realizing a lightweight design of the composite material cylinder.

[0010] The inner layer of the composite material cylinder with inner wall grooves of the present invention is preferably a carbon fiber cloth prepreg composite material, the middle layer is mainly composed of foam profiles and lattice blocks and longitudinal reinforcement ribs embedded in the same layer of foam profiles, and the outer layer is a fiber winding composite material.

[0011] Furthermore, the lattice blocks are made of carbon fiber reinforced composite material or aluminum alloy material, the inner and outer peripheral surfaces of the lattice blocks are consistent with the profile of the foam profile, and the lattice blocks and the foam profile are bonded with structural adhesive.

[0012] Furthermore, the lattice blocks are embedded in groups along the circumference of the middle layer, and the lattice blocks are evenly distributed along the circumference. Preferably, the number is 5 to 6 in a group, and a group of circumferential lattice blocks is set every 150 to 200 mm in the axial direction. Since the pressure gradually decreases near the tail of the barrel, the circumferential number and circumferential spacing can be appropriately reduced according to the finite element simulation results.

[0013] Furthermore, the inner layer cross section is a circular ring or square ring with equal wall thickness and a spacer section, and the outer layer cross section is a regular circular ring or square ring with equal wall thickness.

[0014] Furthermore, the spacing segment includes a curved surface segment that fits with the inner wall of the outer layer and side wall segments that are arranged on both sides of the curved surface segment and are used to connect with the inner layer.

[0015] Furthermore, the ratio of the length of the arc surface segment to the length of the inner layer is 1:10-15.

[0016] Furthermore, the reinforcing ribs are longitudinal reinforcing ribs, and the longitudinal reinforcing ribs are extended and laid from the side wall sections to both sides, and the ratio of the length of the longitudinal reinforcing ribs to the length of the inner layer is 1:15-20.

[0017] Furthermore, the reinforcing ribs are connected by a tenon structure. The reinforcing ribs include a snap-in groove and a snap-in block matched with the snap-in groove, and the entire reinforcing rib is spliced ​​into a whole in sections. In order to prevent the deformation of the reinforcing ribs and facilitate laying, the reinforcing ribs are evenly divided into several sections along the product axis (length) direction, and the sections are connected by a water drop inverted buckle method. This solution allows the sections to be tightly connected into a whole, while limiting the degree of freedom perpendicular to the length direction, effectively solving the inconvenience caused by the entire long reinforcing rib, and at the same time ensuring the integrity of the segmented reinforcing ribs.

[0018] Another object of the present invention is to disclose a method for forming the composite material cylinder with inner wall grooves, which is characterized by comprising the following steps: S1: Use a release agent to treat the mold surface of the inner cavity mold of the cylinder with a boss; S2: Laying the fiber cloth prepreg on the mold, and the laying process adopts the butt-jointing method; S3: Lay release cloth and breathable felt on the surface of the prepreg, and then put in a vacuum bag to evacuate and perform bag pressing; S4: embed the dot matrix blocks in the foam profile prepared in advance and fix them with structural adhesive; S5: According to the cross-sectional shape of the reinforcement rib, the reinforcement rib profile blank is formed by pultrusion process, and then the connection interface is processed; S6: Remove the vacuum bag and lay the middle layer in sections. First, lay the reinforcement ribs from one end of the mold, and then lay the foam profile with dot matrix blocks prepared in S3. After laying each section, use plastic tie to tie the laid foam and reinforcement ribs. Repeat the above steps until the middle layer is laid. S7: After the middle layer is laid, a film is laid on the surface of the middle layer, and then the whole layer is vacuum bagged again; S8: After the bag pressing is completed, the outer layer is wound as a whole. When the fiber yarn runs near the tie during winding, the tie is cut off, and the outer layer is wound according to the procedure. After the winding is completed, it is put into the furnace for curing and then demoulding.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The composite material cylinder with inner wall grooves of the present invention is innovative in structure. According to the stress characteristics of the cylinder with inner wall grooves, a foam profile is arranged in the middle layer with a dot matrix block structure embedded in it to enhance the compressive strength of the foam in the middle layer and improve the overall deformation resistance of the composite material cylinder. At the same time, reinforcing ribs are arranged on both sides of the interval section to effectively reduce the deformation of the special-section cylinder under the action of internal pressure. The overall strength of the cylinder is increased without increasing the weight, thereby realizing a lightweight design of the composite material cylinder.

[0020] The preparation method of the invention solves the difficult problem of forming a composite material cylinder with a special-shaped cross-section and inner wall grooves, and realizes the integrated forming of a composite material cylinder made of multiple materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a cross-sectional view of a circular cylinder of a composite material cylinder with inner wall grooves described in Example 1 of the present invention.

[0022] Figure 2 Schematic diagram of the circular middle layer of the composite material cylinder with inner wall grooves described in Example 1 of the present invention.

[0023] Figure 3 Schematic diagram of the circular inner layer of the composite material cylinder with inner wall grooves described in Example 1 of the present invention.

[0024] Figure 4 This is a schematic diagram of the structure of the reinforcing ribs before splicing described in Example 1 of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure after the reinforcing ribs described in Example 1 of the present invention are spliced.

[0026] Figure 6 A cross-sectional view of a square cylinder of a composite material cylinder with inner wall grooves according to Example 2 of the present invention.

[0027] Figure 7 A cross-sectional view of an inner-circular and outer-square composite material cylinder with inner wall grooves as described in Example 3 of the present invention.

[0028] Among them, 1 is an outer layer, 2 is a middle layer, 21 is a foam profile, 22 is a lattice block, 3 is an inner layer, 4 is a spacing section, 41 is a curved surface section, 42 is a side wall section, 5 is a reinforcing rib, 51 is a clamping groove, and 52 is a clamping block. DETAILED DESCRIPTION

[0029] For the convenience of explaining and understanding the present invention, the following Figure 1-Figure 5 The embodiments of the present invention are described in detail.

[0030] The composite cylinder with inner wall grooves of the present invention comprises an outer layer 1, an intermediate layer 2 and an inner layer 3 from the outside to the inside, wherein a spacing section 4 is provided at the intermediate layer 2, protruding from the inner layer 3 to the outer layer 1; the outer layer 1 and the inner layer 3 are arranged concentrically, the inner circumference of the intermediate layer 2 is in accordance with the outer circumference of the inner layer 3, and the outer circumference of the intermediate layer 2 is in accordance with the inner circumference of the outer layer 1; the outer layer 1 is a fiber-wound composite material, the inner layer 3 is a fiber cloth prepreg, the intermediate layer 2 comprises a foam profile 21, the foam profile 21 is used as a skeleton, and a dot matrix block 22 is embedded in the foam profile 21, and reinforcing ribs 5 are provided on both sides of the spacing section 4, and the reinforcing ribs 5 are formed by segmented splicing. The specific implementation method thereof is shown in the following embodiment. Example 1

[0031] like Figure 1-Figure 3As shown, in the composite cylinder with inner wall grooves of this embodiment, the cross section of the inner layer 3 is a 6mm thick circular ring with a spacer section 4 (inner wall groove), the cross section of the outer layer 1 is a circular ring with an equal wall thickness of 4mm, the cross section of the inner layer 3 except the spacer section 4 is a concentric structure with the cross section of the outer layer 1, the middle layer 2 is located between the inner layer 3 and the outer layer 1, the inner circumference of the middle layer 2 is conformed to the outer circumference of the inner layer 3, and the outer circumference of the middle layer 2 is conformed to the inner circumference of the outer layer 1, the spacer section 4 includes a curved surface section 41 that fits the inner wall of the outer layer 1 and a side wall section 42 that is arranged on both sides of the curved surface section 41 and is used to connect with the inner layer 3, the curved surface section 41 is composed of a composite material of the inner layer and the outer layer, and the inner layer is closely attached to the outer layer. The ratio of the length of the curved surface section 41 to the length of the inner layer 3 is 1:10-15, and preferably 1:12 in this embodiment. The inner side of the curved surface section 41 is an arc structure, and the outer cross section of the curved surface section is an arc structure that fits the outer layer 1. The cross section of the arc surface segment 41 is a structure with uniform thickness.

[0032] The inner layer 3 in this embodiment is a carbon fiber cloth prepreg composite material, the middle layer 2 is mainly composed of a foam profile and a lattice block 22 embedded in the same layer of foam profile, and longitudinal reinforcement ribs, and the outer layer is a carbon fiber winding composite material. The main functions of the carbon fiber cloth prepreg composite material for the launch tube include reducing weight, improving structural strength and durability, and improving the overall performance of the launch tube. The strength of the carbon fiber cloth prepreg composite material is 6 to 12 times that of steel, but the density is only 1 / 4 of that of steel, which makes it have a significant advantage in reducing the weight of the launch tube. The weight reduction of the launch tube can reduce fuel consumption during launch and improve launch efficiency.

[0033] High modulus and high strength carbon fiber wrapped composite materials are used to bear the bending load, and high density foam profiles are used as the middle layer to support the panel and resist shearing.

[0034] In this embodiment, the inner layer 3 fiber cloth prepreg is one or more of plain cloth prepreg, twill cloth prepreg and satin cloth prepreg. In this embodiment, plain cloth is preferred, with a gram weight of 100g / m 2 ~1000g / m 2 .

[0035] The foam profile 21 of the middle layer 2 is one or more of PVC foam, PET foam, PMI foam, etc., preferably PET foam, with a density of 50kg / m 3 ~500kg / m 3 .

[0036] The lattice blocks 22 of the middle layer 2 are made of fiber-reinforced composite materials, and their inner and outer circumferences are consistent with the surface of the foam profile. They are embedded in the foam profile of the same layer, and structural adhesive is used to bond the lattice blocks to the foam. The reinforcement ribs 5 are longitudinal reinforcement ribs, and the longitudinal reinforcement ribs are extended from the side wall section 42 to both sides. The ratio of the length of the longitudinal reinforcement ribs to the length of the inner layer 3 is 1:15-20, and preferably 1:18 in this embodiment. The longitudinal reinforcement ribs are made of fiber-reinforced composite materials with a compressive strength greater than 300MPa, distributed on both sides of the spacing section 4 (inner wall groove), and their inner and outer circumferences are consistent with the surface of the foam profile. Structural adhesive is used to bond the reinforcement ribs 5 to the foam. The reinforcement ribs 5 are formed by segmented splicing along the axial direction, and the reinforcement ribs 5 are connected by a tenon structure. As Figure 4 and Figure 5 As shown, the reinforcing rib 5 in this embodiment includes a clamping groove 51 and a clamping block 52 matched with the clamping groove 51, and the entire reinforcing rib is spliced ​​into a whole in sections. In order to prevent the deformation of the reinforcing rib and facilitate laying, the reinforcing rib 5 is evenly divided into several sections along the product axis (length), and the section A and the section B are connected in a water drop inverted manner. This solution makes the section A and the section B tightly connected into a whole, and at the same time limits the degree of freedom perpendicular to the length direction, effectively solving the inconvenience caused by the entire long reinforcing rib, while ensuring the integrity of the segmented reinforcing rib.

[0037] The steps of the molding method of the composite material cylinder with inner wall grooves in this embodiment are as follows: S1: Use a release agent to treat the mold surface of the cylinder inner cavity mold with a boss.

[0038] S2: Lay the fiber cloth prepreg on the mold, and the laying process adopts the butt-jointing method.

[0039] S3: Lay release cloth and breathable felt on the surface of the prepreg, and then put in a vacuum bag to evacuate and perform bag pressing.

[0040] S4: Embed the dot matrix blocks in the foam profile prepared in advance and fix them with structural adhesive.

[0041] S5: According to the cross-sectional shape of the reinforcement rib, the reinforcement rib profile blank is formed by pultrusion process, and then the connection interface is processed.

[0042] S6: Remove the vacuum bag and lay the middle layer in sections. First, lay the reinforcement ribs from one end of the mold, and then lay the foam profile with dot matrix blocks prepared in S3. After laying each section, use plastic tie to tie the laid foam and reinforcement ribs. Repeat the above steps until the middle layer is laid.

[0043] S7: After the middle layer is laid, a film is laid on the surface of the middle layer, and then the whole layer is vacuum bagged again.

[0044] S8: After the bag pressing is completed, the outer layer is wound as a whole. When the fiber yarn runs near the tie during winding, the tie is cut off, and the outer layer is wound according to the procedure. After the winding is completed, it is put into the furnace for curing and then demoulding.

[0045] The composite cylinder of this embodiment has a special-shaped cross section, which greatly increases the difficulty of design and manufacturing. This preparation method solves the problem of forming a composite cylinder with a special-shaped cross section and inner wall grooves, and realizes the integrated forming of a composite cylinder made of multiple materials. Example 2

[0046] like Figure 6 As shown, the composite cylinder with inner wall grooves in this embodiment is prepared in the same way as in Example 1, but its structure is different. From outside to inside, it includes an outer layer 1, an intermediate layer 2 and an inner layer 3, the intermediate layer 2 is provided with a spacing section 4 protruding from the inner layer 3 to the outer layer 1, the outer layer 1 and the inner layer 3 are arranged concentrically, the inner circumference of the intermediate layer 2 is in accordance with the outer circumference of the inner layer 3, and the outer circumference of the intermediate layer 2 is in accordance with the inner circumference of the outer layer 1; the outer layer 1 is a fiber-wound composite material, the inner layer 3 is a fiber cloth prepreg, the intermediate layer 2 includes a foam profile 21 as a skeleton, the foam profile 21 is embedded with a lattice block 22, and reinforcing ribs 5 are provided on both sides of the spacing section 4, and the reinforcing ribs 5 are formed by segmented splicing. The foam profile 21 in this embodiment is replaced by an aramid honeycomb or aluminum honeycomb structure, and the composite material lattice block 22 and the longitudinal reinforcing ribs are made of lightweight metals such as aluminum alloy.

[0047] The cross section of the inner layer 3 is a 3mm thick square ring with a spacer section 4 (inner wall groove), and the cross section of the outer layer 1 is a square ring with an equal wall thickness of 5mm. The inner layer section and the outer layer section except the groove are concentric structures. The middle layer 2 is located between the inner layer 3 and the outer layer 1. The inner circumference of the middle layer 2 is in accordance with the outer circumference of the inner layer 3, and the outer circumference of the middle layer 2 is in accordance with the inner circumference of the outer layer 1. The spacer section 4 includes a curved surface section 41 that fits the inner wall of the outer layer 1 and a side wall section 42 that is arranged on both sides of the curved surface section 41 and is used to connect with the inner layer 3. The curved surface section 41 is composed of a composite material of the inner layer and the outer layer, and the inner layer is closely attached to the outer layer. The inner side of the curved surface section 41 is an inverted V-shaped structure, and the outer cross section of the curved surface section fits the outer layer 1 to form a rectangular structure. The cross section of the curved surface section 41 is a variable diameter structure that is thin in the middle and thick on both sides, and this structure has a stronger bearing capacity. Example 3

[0048] like Figure 7As shown, the composite cylinder with inner wall grooves in this embodiment is prepared in the same way as in Example 1, but its structure is different. From outside to inside, it includes an outer layer 1, an intermediate layer 2 and an inner layer 3, the intermediate layer 2 is provided with a spacing section 4 protruding from the inner layer 3 to the outer layer 1, the outer layer 1 and the inner layer 3 are arranged concentrically, the inner circumference of the intermediate layer 2 is in accordance with the outer circumference of the inner layer 3, and the outer circumference of the intermediate layer 2 is in accordance with the inner circumference of the outer layer 1; the outer layer 1 is a fiber-wound composite material, the inner layer 3 is a fiber cloth prepreg, the intermediate layer 2 includes a foam profile 21 as a skeleton, and a dot matrix block 22 is embedded in the foam profile 21, and reinforcing ribs 5 are provided on both sides of the spacing section 4, and the reinforcing ribs 5 are formed by segmented splicing. The dot matrix blocks 22 of the intermediate layer 2 in this embodiment are equivalently replaced by multiple longitudinal reinforcing ribs arranged along the axis and annular reinforcing ribs arranged along the radial direction.

[0049] The composite cylinder with inner wall grooves in this embodiment is specifically as follows: the cross section of the inner layer 3 is a 4mm thick circular ring with a spacer section 4 (inner wall groove), the cross section of the outer layer 1 is a square ring with an equal wall thickness of 7mm, the cross section of the inner layer 3 except the groove is a concentric structure with the cross section of the outer layer 1, the middle layer 2 is located between the inner layer and the outer layer, the inner circumference of the middle layer 2 is in accordance with the outer circumference of the inner layer, and the outer circumference of the middle layer 2 is in accordance with the inner circumference of the outer layer. The spacer section 4 includes a curved surface section 41 that fits the inner wall of the outer layer 1 and a side wall section 42 that is arranged on both sides of the curved surface section 41 and is used to connect with the inner layer 3. The curved surface section 41 is composed of a composite material of the inner layer and the outer layer, and the inner layer is close to the outer layer. The curved surface section 41 is a smooth curved surface structure. The cross section of the curved surface section 41 is a variable diameter structure that is thin in the middle and thick on both sides.

[0050] The composite material cylinder with inner wall grooves of the present invention is innovative in structure. According to the stress characteristics of the cylinder with inner wall grooves, a foam profile is arranged in the middle layer with a dot matrix block structure embedded in it to enhance the compressive strength of the foam in the middle layer and improve the overall deformation resistance of the composite material cylinder. At the same time, reinforcing ribs are arranged on both sides of the interval section to effectively reduce the deformation of the special-section cylinder under the action of internal pressure. The overall strength of the cylinder is increased without increasing the weight, thereby realizing a lightweight design of the composite material cylinder.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention.

Claims

1. A composite material cylinder with inner wall grooves, characterized in that: From the outside to the inside, the outer layer (1), the middle layer (2) and the inner layer (3) are sequentially included. At the middle layer (2), a spacing section (4) is provided protruding from the inner layer (3) toward the outer layer (1). The outer layer (1) and the inner layer (3) are arranged concentrically. The inner peripheral surface of the middle layer (2) is conformed to the outer peripheral surface of the inner layer (3), and the outer peripheral surface of the middle layer (2) is conformed to the inner peripheral surface of the outer layer (1). The outer layer (1) is a fiber-wound composite material, the inner layer (3) is a fiber cloth prepreg, the middle layer (2) includes a foam profile (21), and the foam profile (21) is used as a skeleton and has a dot matrix block (22) embedded therein. Reinforcing ribs (5) are provided on both sides of the spacing section (4). The reinforcing ribs (5) are formed by segmented splicing to prevent the reinforcing ribs from deforming, so that the segments are connected to form a whole.

2. The composite material cylinder with inner wall grooves according to claim 1, characterized in that: The lattice block (22) is made of carbon fiber reinforced composite material or aluminum alloy material, the inner and outer peripheral surfaces of the lattice block (22) are consistent with the profile of the foam profile, and the lattice block (22) and the foam profile are bonded using structural adhesive.

3. The composite material cylinder with inner wall grooves according to claim 2, characterized in that: The lattice blocks (22) are embedded in groups along the circumference of the middle layer (2), and the lattice blocks (22) are evenly distributed along the circumference.

4. The composite material cylinder with inner wall grooves according to claim 3, characterized in that: The cross section of the inner layer (3) is a circular ring or square ring with a constant wall thickness and a spacer section (4), and the cross section of the outer layer (1) is a regular circular ring or square ring with a constant wall thickness.

5. The composite material cylinder with inner wall grooves according to claim 4, characterized in that: The spacing segment (4) comprises a curved surface segment (41) that fits the inner wall of the outer layer (1) and side wall segments (42) that are arranged on both sides of the curved surface segment (41) and are used to connect with the inner layer (3).

6. The composite material cylinder with inner wall grooves according to claim 5, characterized in that: The ratio of the length of the arc surface segment (41) to the length of the inner layer (3) is 1:10-15.

7. The composite material cylinder with inner wall grooves according to claim 6, characterized in that: The reinforcing ribs (5) are longitudinal reinforcing ribs, and the longitudinal reinforcing ribs are extended from the side wall section (42) to both sides, and the ratio of the length of the longitudinal reinforcing ribs to the length of the inner layer (3) is 1:15-20.

8. The composite material cylinder with inner wall grooves according to claim 5, characterized in that: The reinforcing ribs (5) are connected with each other by means of a tenon structure, and the reinforcing ribs (5) comprise a clamping groove (51) and a clamping block (52) adapted to the clamping groove (51).

9. The method for forming a composite material cylinder with inner wall grooves according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Use a release agent to treat the mold surface of the inner cavity mold of the cylinder with a boss; S2: Laying the fiber cloth prepreg on the mold, and the laying process adopts the butt-jointing method; S3: Lay release cloth and breathable felt on the surface of the prepreg, and then put in a vacuum bag to evacuate and perform bag pressing; S4: embedding the dot matrix block (22) in the foam profile (21) prepared in advance, and fixing it with structural adhesive; S5: forming a reinforcement rib profile blank by pultrusion according to the cross-sectional shape of the reinforcement rib (5), and then processing a connection interface; S6: Remove the vacuum bag and lay the middle layer (2) in sections. First, lay the reinforcing ribs (5) from one end of the mold, and then lay the foam profile with dot matrix blocks prepared in S3. After each section is laid, use a plastic tie to tie the laid foam profile and reinforcing ribs (5). Repeat the above steps until the middle layer (2) is laid. S7: After the middle layer (2) is laid, a film is laid on the surface of the middle layer (2), and the whole layer is vacuum bagged again; S8: After the bagging is completed, the outer layer (1) is wound as a whole. When the fiber yarn runs near the tie during winding, the tie is cut off, and the outer layer is wound according to the procedure. After the winding is completed, it is put into the furnace for curing and then demoulding.

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