Composite material conical grid forming mold and forming method

Abstract

The invention discloses a composite material conical grid forming mold and a forming method, and relates to a grid forming mold and a forming method. The invention aims to solve the problems that the forming technology of the carbon fiber composite material is high in threshold, the quality control requirement is strict, the material utilization rate is not satisfactory, the cost control pressure is obviously increased, and the design complexity is obviously improved. The upper disc with the hole is mounted at one end of the conical supporting seat through a plurality of connecting and fixing pieces, and the lower disc with the hole is mounted at the other end of the conical supporting seat through a plurality of connecting and fixing pieces. The method comprises the steps that firstly, the conical supporting bases are spliced; 2, laying the prepreg tape according to the groove track of the soft film A, and placing the bulges of the soft film B in the corresponding grooves on the soft film A one by one; thirdly, the assembled forming mold is put into a vacuum sealing bag; fourthly, forming operation in the third step is completed. The invention relates to the technical field of prepreg tape winding forming.

Description

Technical Field

[0001] The invention relates to a grid forming die and a forming method, in particular to a composite material conical grid forming die and a forming method, and the invention relates to the technical field of prepreg tape winding forming. Background Art

[0002] Carbon fiber composite materials, with their excellent light weight and high strength characteristics, are widely used in the field of aerospace load-bearing structures. In order to further optimize the structural performance, that is, to achieve the ultimate weight reduction while maintaining the necessary strength and load-bearing capacity, the skinless composite grid cone shell structure came into being and is widely used in key rocket structures such as satellite brackets and interstages. This design not only exquisitely meets the strict requirements of the precision instruments inside the structure for efficient heat dissipation, but also shows the advantages of specific strength and specific stiffness, becoming an important force in promoting the advancement of aerospace technology. Although its preparation process combines multiple advantages such as light weight, high strength and excellent heat dissipation performance, the manufacturing process of the skinless composite grid cone shell structure also faces many challenges. The high threshold of molding technology, the strict requirements of quality control, the unsatisfactory material utilization rate, the pressure of cost control and the significant increase in design complexity are all technical problems that need to be solved urgently. These challenges not only test the innovation ability and skill level of engineers, but also inspire the entire industry to continuously explore more efficient, economical and reliable manufacturing solutions to promote the widespread application and sustainable development of carbon fiber composite materials in the aerospace field. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of high threshold of carbon fiber composite material molding technology, strict requirements of quality control, unsatisfactory material utilization, pressure of cost control and significantly increased design complexity, and then provide a composite material conical grid molding mold and molding method.

[0004] The technical solution adopted by the present invention to solve the above problems is:

[0005] A composite material conical grid forming die, comprising a conical support seat, an upper disc with holes, a lower disc with holes, a silicone film sleeve and a plurality of connecting fixings;

[0006] The silicone membrane sleeve is arranged on the conical support seat, the upper disc with holes is installed on one end of the conical support seat through a plurality of connecting and fixing parts, and the lower disc with holes is installed on the other end of the conical support seat through a plurality of connecting and fixing parts.

[0007] Furthermore, the conical support seat is composed of at least three arc-shaped shells arranged radially and assembled to form a conical shell.

[0008] Furthermore, an arc-shaped plate body is fixedly installed at both ends of the arc-shaped shell respectively, and the arc-shaped plate bodies at the upper ends of the multiple arc-shaped shells are assembled to form a flange ring. The upper disc with holes is fixedly connected to the flange ring assembled at one end of the arc-shaped shell by multiple connecting and fixing parts, and the lower disc with holes is fixedly connected to the flange ring assembled at the other end of the arc-shaped shell by multiple connecting and fixing parts.

[0009] Furthermore, the silicone film sleeve includes a silicone soft film A and a silicone soft film B; the silicone soft film A is a conical sleeve structure composed of multiple soft films A assembled together, and the silicone soft film B is a conical sleeve structure composed of multiple soft films B assembled together.

[0010] Furthermore, a grid groove is provided on the outer wall of the soft film A, and a grid protrusion corresponding to the grid groove on the soft film A is provided on the inner wall of the soft film B. The grid groove of each soft film A is arranged correspondingly to the grid protrusion of the soft film B. A connecting protrusion is processed on the outer wall at one end of each soft film A, and a connecting groove is processed at the other end of each soft film A. The connecting protrusion of the outer wall of each soft film A is inserted in the connecting groove of the soft film A to form a conical sleeve. A connecting protrusion is processed on the outer wall at one end of each soft film B, and a connecting groove is processed at the other end of each soft film B. The connecting protrusion of the outer wall of each soft film B is inserted in the connecting groove of the soft film B to form a conical sleeve.

[0011] Furthermore, the parameter equations of the spiral ribs and the annular ribs of the silicone membrane sleeve are:

[0012] The parametric equation of the helix between any two points can be expressed as

[0013]

[0014] Among them, x, y, z represent the position parameters of any point on the spiral line, ρ represents the distance from any point on the spiral line to the origin, θ represents the angle of any point on the spiral line, and θ f and θ0 are the angular coordinates of the starting point and the end point of the conical spiral, β represents the half angle of the cone, f(θ) represents the functional relationship between the meridian coordinate and the angular coordinate, and the functions corresponding to the equiangular spiral rib, the equidistant spiral rib and the geodesic spiral rib are respectively represented by f g (θ), f l (θ) and f d (θ) indicates that its expression is

[0015]

[0016] The constant C0 of the geodesic spiral rib is determined by the Clairaut equation, as shown in formula (6), where e is the natural base, ρ f is the distance from the upper end point of the geodesic spiral to the origin, α f g represents the helix angle of the geodesic helix at the starting point, αl is the helix angle of the equiangular spiral, a is the ratio of the meridian coordinate to the angular coordinate of the equidistant spiral, and the superscripts g, l, and d represent the geodesic spiral rib, equiangular spiral rib, and equidistant spiral rib, respectively;

[0017] Another spiral rib is obtained by making the above spiral symmetrical with respect to any meridian in the YOZ plane. The parametric equation of the spiral is

[0018]

[0019] After rotating along the center of the conical shell section, a structure with uniform distribution of spiral ribs can be obtained. When the total number of spiral ribs is n h When , the parametric equation of the i-th spiral reinforcement is

[0020]

[0021] Among them, θ h represents the angle between the intersection points of two consecutive spiral ribs, θ h =π / n h ;

[0022] The annular reinforcement divides the upper and lower spiral reinforcement into two equal parts, then the parameter equation of the kth annular reinforcement can be expressed as

[0023]

[0024] Among them, 0≤θ≤2π, 2≤k≤n c -1,n c is the number of annular reinforcements.

[0025] A method for forming a composite material conical grid forming mold is implemented according to the following steps:

[0026] Step 1: Assemble the conical support seat, fix the upper disc with holes on one end of the conical support seat through multiple connecting fixtures, and fix the lower disc with holes on the other end of the conical support seat through multiple connecting fixtures, and lay each soft film A of the silicone soft film A on the outside of the conical support seat;

[0027] Step 2: Lay the prepreg tape along the groove track of soft film A on silicone soft film A, ensure that each layer of the groove of soft film A is laid accurately, and place the protrusions of soft film B on silicone soft film B into the corresponding grooves on soft film A one by one, and fit the protrusions of soft film B tightly with the grooves of soft film A to form a seamless overall structure;

[0028] Step 3: Place the assembled molding mold into a vacuum sealed bag and place it into a high temperature container for molding;

[0029] Step 4: After the molding operation in step 3 is completed, remove the silicone soft film B, remove the connecting fixtures, the upper disc with holes, the lower disc with holes and the conical support seat, and demold the composite tapered grid on the silicone soft film A, and carefully polish the uneven areas until the surface is as smooth as a mirror, and then a complete composite tapered grid structure can be obtained. Furthermore, in step 3, the assembled molding mold is placed in a vacuum sealed bag to isolate it from external interference, and then the entire sealed bag is transferred to the autoclave, and through the precisely controlled temperature and pressure, efficient and uniform hot pressing molding is carried out to ensure that the materials are tightly combined and reach the preset shape.

[0030] Furthermore, in step three, when the sealing bag and the molding mold are transferred to the autoclave, they are heated and pressurized by slowly heating and pressurizing in stages to fully compact the material, eliminate internal voids, and ensure the density and quality of the final product. Finally, the temperature is slowly reduced to 80°C through the cooling stage, and attention is paid to the stability of temperature control.

[0031] Furthermore, in step 3, the assembled molding die is placed in a vacuum sealed bag, all bubbles and impurities are completely removed by vacuum, and then the sealed bag is transferred to a hot box to promote the curing and molding of the material in a high temperature environment.

[0032] 1. The present application is applied to a wound composite material grid conical shell structure with good molding quality, high manufacturing efficiency and low manufacturing cost. The use of silicone soft film increases the designability and substitutability of the grid type.

[0033] 2. The composite grid conical shell forming mold and forming method of the present invention can be applied to the forming of composite grid conical shell structural parts. Its significant advantages lie in the economical manufacturing cost, slight damage to the components during the demolding process, the convenience of mold assembly and the high flexibility of grid design. These characteristics jointly promote a double leap in the manufacturing efficiency and quality of composite structural parts.

[0034] 3. The silicone soft film mold described in the present invention, through advanced splicing technology, achieves precise adaptation to a variety of grid shapes, including but not limited to classic triangles, quadrilaterals and even complex hexagonal geometric shapes. This unprecedented flexibility greatly broadens the application field of the mold and meets the diversified needs of the market.

[0035] Fourth, the silicone soft film of the present invention is made of silicone rubber material with a high thermal expansion coefficient. This choice not only optimizes the demoulding process, reduces the risk of component damage, but also ensures the high quality of the molded product. The close fit between the silicone soft film and the conical bottom plate, coupled with sufficient friction design, effectively prevents the mold from sliding during the molding process, further ensuring molding accuracy and stability.

[0036] 5. The ends of the silicone soft film A (6) and the silicone soft film B (7) of the present application are equipped with regular circular convex snap-on structures, which cleverly match the corresponding concave snap-on structures, thereby achieving a seamless and firm connection between the head and tail of the silicone soft film, significantly enhancing the stability and durability of the overall structure, and providing a solid guarantee for the precise forming of complex grid conical shells. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the overall structure of this application.

[0038] Figure 2 It is a schematic diagram of a conical support seat 1, an upper disc with holes 2, a lower disc with holes 3 and a plurality of connecting fixings 5 ​​before assembly.

[0039] Figure 3 Schematic diagram of the mold for processing soft film A and soft film B.

[0040] Figure 4 Schematic diagram of the structure of soft film A and soft film B. The left end of soft film A and the left end of soft film B are connecting protrusion structures, and the back sides of the right end of soft film A and the right end of soft film B are corresponding connecting groove structures.

[0041] Figure 5 Schematic diagram of spiral ribs on a conical mesh.

[0042] Figure 6 Schematic diagram of conical mesh spiral reinforcement, figure a is geodesic spiral reinforcement, figure b is equiangular spiral reinforcement, and figure c is a schematic diagram of equidistant spiral reinforcement.

[0043] Figure 7 It is a schematic diagram of the component after forming according to the present invention. DETAILED DESCRIPTION

[0044] Specific implementation method 1: Combination Figure 1-Figure 6 The present embodiment is described as a composite material conical grid forming mold, which comprises a conical support seat 1, an upper disc with holes 2, a lower disc with holes 3, a silicone film sleeve 4 and a plurality of connecting fixings 5;

[0045] The silicone membrane sleeve 4 is sleeved on the conical support seat 1, the upper disc 2 with holes is installed on one end of the conical support seat 1 through multiple connecting fixtures 5, and the lower disc 3 with holes is installed on the other end of the conical support seat 1 through multiple connecting fixtures 5.

[0046] Specific implementation method 2: Combination Figure 1 , Figure 2This embodiment describes a composite material conical grid forming die, wherein the conical support seat 1 is composed of at least three arc-shaped shells arranged radially and assembled to form a conical shell. Other methods are the same as those of the first embodiment.

[0047] When the conical support seat 1 is composed of three arc-shaped shells, the central angle of the arc-shaped shell is 120°, and the mold has flexibility and applicability through flexible assembly of the arc-shaped shells.

[0048] Specific implementation method three: Combination Figure 1 , Figure 2 This embodiment is described. In this embodiment, a composite material conical grid forming die is described. An arc plate is fixedly installed at each end of the arc shell. The arc plates at the upper ends of the arc shell are assembled to form a flange ring. The upper disc 2 with holes is fixedly connected to the flange ring assembled at one end of the arc shell through multiple connecting and fixing parts 5. The lower disc 3 with holes is fixedly connected to the flange ring assembled at the other end of the arc shell through multiple connecting and fixing parts 5. Other methods are the same as those in the second embodiment.

[0049] Specific implementation method 4: Combination 1- Figure 4 This embodiment describes a composite material conical grid forming mold, wherein the silicone film sleeve 4 includes a silicone soft film A6 and a silicone soft film B7; the silicone soft film A6 is a conical sleeve structure composed of a plurality of soft films A, and the silicone soft film B7 is a conical sleeve structure composed of a plurality of soft films B. Other methods are the same as those in the third embodiment.

[0050] Specific implementation method five: Combination 1- Figure 4The present embodiment is described. The present embodiment describes a composite material conical grid forming mold, wherein a grid groove is provided on the outer wall of the soft film A, and a grid protrusion corresponding to the grid groove on the soft film A is provided on the inner wall of the soft film B. The grid groove of each soft film A is arranged corresponding to the grid protrusion of the soft film B. A connecting protrusion is processed on the outer wall at one end of each soft film A, and a connecting groove is processed on the other end of each soft film A. The connecting protrusion of the outer wall of each soft film A is inserted in the connecting groove of the soft film A to form a conical sleeve, and the superimposed thickness of the connecting protrusion on the soft film A inserted in the connecting groove is the same as the wall thickness of the conical sleeve. A connecting protrusion is processed on the outer wall at one end of each soft film B, and a connecting groove is processed on the other end of each soft film B. The connecting protrusion of the outer wall of each soft film B is inserted in the connecting groove of the soft film B to form a conical sleeve, and the superimposed thickness of the connecting protrusion on the soft film B inserted in the connecting groove is the same as the wall thickness of the conical sleeve. The silicone film sleeve 4 is essentially formed by stretching the silicone soft film A, locking the soft film A head and tail through the connecting protrusion and connecting groove structure on the soft film A, and then relying on the greater friction brought by the tightening effect to fit itself on the conical support seat. The soft film B is locked head and tail through the connecting protrusion and connecting groove structure on the soft film B, and then relying on the greater friction brought by the tightening effect to fit itself on the conical support seat. Other methods are the same as the specific implementation method four.

[0051] In this embodiment, the prepreg tape is wound and laid through the groove part of the silicone soft film A6. After laying, the silicone soft film B7 is combined with the silicone soft film A6; after being wrapped in a vacuum bag, it is moved into the autoclave for hot pressing molding; after molding, the silicone soft film A6 is removed, and the connecting fixings 5, the upper disc with holes 2, the lower disc with holes 3 and the conical support seat 1 are removed to demold the composite grid cone shell on the silicone soft film A6, and finally the edges and intersections are polished to obtain a complete composite grid cone shell structure.

[0052] Soft film A and soft film B are precisely molded by the mold. The groove layout of soft film A corresponds to the preset laying trajectory of the prepreg tape; while soft film B is equipped with a convex structure. The two complement each other and jointly define the thickness of the grid structure. This combination of concave and convex structures not only simplifies the molding process, but also ensures the precise control of the grid size. The geometric dimensions of the grooves and convexities of soft film A and soft film B, including width and thickness, are precisely set according to specific design specifications and requirements. In particular, in the area where the grooves and convexities of the mold intersect with each other, a thickening and chamfering design is adopted, which effectively avoids the obstruction of the prepreg tape when laying at complex intersections, ensures that the tape can be smoothly spread, and achieves seamless and uniform bonding with the surface of the silicone soft film, thereby significantly improving the final quality and performance of the composite grid cone shell.

[0053] Specific implementation method six: Combination 1- Figure 4This embodiment describes a composite material conical grid forming mold described in this embodiment, and the parameter equations of the spiral ribs and the annular ribs of the silicone film sleeve 4 are:

[0054] The parametric equation of the helix between any two points can be expressed as

[0055]

[0056] Among them, θ f and θ0 are the angular coordinates of the starting point and the end point of the conical spiral, β represents the half angle of the cone, f(θ) represents the functional relationship between the meridian coordinate and the angular coordinate, and the functions corresponding to the equiangular spiral rib, the equidistant spiral rib and the geodesic spiral rib are respectively represented by f g (θ), f l (θ) and f d (θ) indicates that its expression is

[0057]

[0058] Among them, α is determined by the Clairaut equation. f g represents the spiral angle of the geodesic spiral at the starting point, α l is the helix angle of the equiangular spiral, a is the ratio of the meridian coordinate to the angular coordinate of the equidistant spiral, and the superscripts g, l, and d represent the geodesic spiral rib, equiangular spiral rib, and equidistant spiral rib, respectively;

[0059] Another spiral rib is obtained by making the above spiral symmetrical with respect to any meridian in the YOZ plane. The parametric equation of the spiral is

[0060]

[0061] After rotating along the center of the conical shell section, a structure with uniform distribution of spiral ribs can be obtained. When the total number of spiral ribs is n h When , the parametric equation of the i-th spiral reinforcement is

[0062]

[0063] Among them, θ h represents the angle between the intersection points of two consecutive spiral ribs, θ h =π / n h ;

[0064] The annular reinforcement divides the upper and lower spiral reinforcement into two equal parts, then the parameter equation of the kth annular reinforcement can be expressed as

[0065]

[0066] Among them, 0≤θ≤2π, 2≤k≤n c -1,nc The other methods are the same as those in the fourth or fifth embodiment.

[0067] In this embodiment, there are three design methods for the spiral line corresponding to the spiral rib, namely, geodesic spiral rib, equiangular spiral rib and equidistant spiral rib.

[0068] The geodesic spiral refers to the spiral motion along the geodesic direction of the cone (i.e. the shortest path direction), which is the local shortest path between two points in space.

[0069] An equiangular helix is ​​a helix whose angle between the tangent at any point on the helix and the cone axis remains constant. The projection of this helix on the cone surface is still a straight line, but the "tightness" or "sparseness" of its helix is ​​different from that of the line cone surface helix because it is controlled by keeping the angle between the tangent and the axis constant.

[0070] An equidistant spiral rib refers to a spiral line in which the difference between the distance from any point on the spiral line to the cone axis (i.e. the radial distance of the point) and the distance from its projection on the cone surface to the cone base remains constant. The projection of this spiral line on the cone surface is not a straight line, but a curve that gradually changes as the spiral rises or falls.

[0071] The constant C0 of the geodesic spiral can be expressed as

[0072]

[0073] Where ρ0 is the distance from the lower end point of the geodesic spiral to the origin.

[0074] According to the parameter formula of the equiangular spiral, the coordinate difference between the starting point and the end point on the curve has the following relationship

[0075]

[0076] Where h is the height of the grid cone shell. The constant α l The expression is

[0077]

[0078] The expression of the constant a of equidistant spiral reinforcement is:

[0079]

[0080] The spacing of the spiral ribs in the grid cone shell structure changes with the radius of the cone. When the size of the unit cell is small enough, the spacing between adjacent spiral ribs can be approximated by the spiral angle at the intersection of the section radius and the unit cell.

[0081]

[0082] Where R is the radius corresponding to a point on the spiral.

[0083] According to the spacing of spiral ribs, the spacing of annular ribs of the three types of grid cone shell structures are

[0084]

[0085] The spacing of the spiral ribs is determined by the arc formed by the annular ribs and the adjacent spiral ribs. Therefore, the calculation formula for the spacing of the spiral ribs is similar for the three types of grid cone shell structures. Except for the spacing of the geodesic spiral ribs, the remaining spacings are obtained by the parametric equations of the spiral ribs and the annular ribs. The total length of the grid cone shell structure includes the total length of the spiral ribs and the annular ribs. The arc length of the conical spiral ribs can be expressed as

[0086]

[0087] The parameter equations of the spiral reinforcement of the conical shell structure with three types of grids are introduced. The length of a single spiral reinforcement can be expressed as

[0088]

[0089] The total length of the spiral reinforcement of the conical shell structure of the three types of grids is

[0090]

[0091] According to the above formula, the length of the kth annular reinforcement is s ck =2πρ k Sinβ. Substituting equation (5) into this formula, we can obtain the total lengths of the annular ribs of the conical shell structure of the three types of grids:

[0092]

[0093] Among them, R1 and R2 are the radii of the upper and lower circles of the mesh cone shell, respectively.

[0094] Specific implementation method seven: Combination Figure 1-Figure 5 This embodiment describes a method for forming a composite material conical grid forming mold, and the method is implemented according to the following steps:

[0095] Step 1: Assemble the conical support seat 1, the upper disc 2 with holes is fixedly installed on one end of the conical support seat 1 through multiple connecting fixtures 5, and the lower disc 3 with holes is fixedly installed on the other end of the conical support seat 1 through multiple connecting fixtures 5, and each soft film A of the silicone soft film A6 is laid on the outside of the conical support seat 1;

[0096] Step 2: Lay the prepreg tape along the groove track of the soft film A on the silicone soft film A6, ensure that each layer of the groove of the soft film A is accurately laid in place, and place the protrusions of the soft film B on the silicone soft film B7 into the corresponding grooves on the soft film A one by one, and fit the protrusions of the soft film B tightly with the grooves of the soft film A to form a seamless overall structure;

[0097] Step 3: Place the assembled molding mold into a vacuum sealed bag and place it into a high temperature container for molding;

[0098] Step 4: After the molding operation in step 3 is completed, remove the silicone soft film B7, remove the connecting fixings 5, the upper disc with holes 2, the lower disc with holes 3 and the conical support seat 1, and demould the composite material conical grid on the silicone soft film A6, and carefully polish the uneven parts until the surface is as smooth as a mirror, and then a complete composite material conical grid structure can be obtained.

[0099] Specific implementation method eight: Combination Figure 1-Figure 5 This embodiment describes a method for forming a composite material conical grid forming mold, and the method is implemented according to the following steps:

[0100] In step 3, the assembled molding mold is placed in a vacuum sealed bag to isolate it from external interference, and then the entire sealed bag is transferred to the autoclave, where it is subjected to efficient and uniform hot pressing molding through precisely controlled temperature and pressure to ensure that the materials are tightly combined and reach a preset shape. Other methods are the same as those in the seventh embodiment.

[0101] Specific implementation method nine: Combination Figure 1-Figure 5 This embodiment describes a method for forming a composite material conical grid forming mold, and the method is implemented according to the following steps:

[0102] In step 3, when the sealed bag and the forming mold are transferred to the autoclave, the sealed bag and the forming mold are heated and pressurized by slowly heating and pressurizing in stages to fully compact the material, eliminate internal voids, and ensure the density and quality of the final product. Finally, the temperature is slowly reduced to 80° C. in the cooling stage, and attention is paid to the stability of temperature control. Other methods are the same as those in the eighth embodiment.

[0103] Specific implementation method ten: Combination Figure 1-Figure 5 This embodiment describes a method for forming a composite material conical grid forming mold, and the method is implemented according to the following steps:

[0104] In step three, the assembled molding mold is placed in a vacuum sealed bag, and all bubbles and impurities are completely removed by vacuum extraction, and then the sealed bag is transferred to a hot box to promote the curing and molding of the material using a high temperature environment. Other methods are the same as those in the seventh embodiment.

[0105] In this application, after the silicone soft film A6 and the silicone soft film B7 are laid, the prepreg tape, the conical support seat 1, the upper disc with holes 2, the lower disc with holes 3, the silicone film sleeve 4 and the multiple connecting fixtures 5 are placed in a vacuum bag for sealing, and the air tightness of the vacuum bag is checked to see if it is good. After being placed in the autoclave, the parameters of the hot pressing curing molding are determined by the properties of the prepreg tape material used. Taking the carbon fiber epoxy resin-based composite material T300 as an example, it first enters the first heating stage. The target temperature of this stage is set to 80°C. The slow and steady heating rate of 2°C per minute is used to ensure that the material is evenly heated to avoid thermal stress concentration. Then it enters the first pressurization stage. At this time, the target pressure is set to 0.1MPa, and the pressure level is maintained for 30 minutes, aiming to initially compact the material and promote resin flow and fiber infiltration. This is followed by a secondary heating stage, with the target temperature raised to 130°C, which further promotes the curing reaction of the resin and improves the overall strength and heat resistance of the material. After the second heating, the second pressurization stage begins, with the target pressure increased to 0.3MPa and maintained for 90 minutes to fully compact the material, eliminate internal voids, and ensure the density and quality of the final product. Finally, the temperature is slowly lowered to 80°C through the cooling stage. This step also focuses on the stability of temperature control to prevent the material from generating internal stress or deformation due to rapid temperature changes.

[0106] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A composite material conical grid forming die, characterized in that: It comprises a conical support seat (1), an upper disc with holes (2), a lower disc with holes (3), a silicone film sleeve (4) and a plurality of connecting fixing parts (5); The silicone membrane sleeve (4) is sleeved on the conical support seat (1), the upper disc (2) with holes is installed on one end of the conical support seat (1) through a plurality of connecting and fixing parts (5), and the lower disc (3) with holes is installed on the other end of the conical support seat (1) through a plurality of connecting and fixing parts (5).

2. A composite material conical grid forming mold according to claim 1, characterized in that: The conical support seat (1) is composed of at least three arc-shaped shells which are arranged radially and assembled to form a conical shell.

3. A composite material conical grid forming mold according to claim 2, characterized in that: An arc-shaped plate body is fixedly mounted on each of the two ends of the arc-shaped shell, and the arc-shaped plates at the upper ends of the arc-shaped shell are assembled to form a flange ring. The upper disc with holes (2) is fixedly connected to the flange ring assembled at one end of the arc-shaped shell through a plurality of connecting and fixing parts (5), and the lower disc with holes (3) is fixedly connected to the flange ring assembled at the other end of the arc-shaped shell through a plurality of connecting and fixing parts (5).

4. The composite tapered grid forming die according to claim 1, characterized in that: The silicone membrane sleeve (4) comprises a silicone soft membrane A (6) and a silicone soft membrane B (7); the silicone soft membrane A (6) is a conical sleeve structure composed of a plurality of soft membranes A assembled together, and the silicone soft membrane B (7) is a conical sleeve structure composed of a plurality of soft membranes B assembled together.

5. A composite material conical grid forming die according to claim 4, characterized in that: A grid groove is provided on the outer wall of the soft film A, and a grid protrusion corresponding to the grid groove on the soft film A is provided on the inner wall of the soft film B. The grid groove of each soft film A is arranged corresponding to the grid protrusion of the soft film B. A connecting protrusion is processed on the outer wall at one end of each soft film A, and a connecting groove is processed at the other end of each soft film A. The connecting protrusion of the outer wall of each soft film A is inserted in the connecting groove of the soft film A to form a conical sleeve, and the thickness of the connecting protrusion on the soft film A inserted in the connecting groove is the same as the wall thickness of the conical sleeve. A connecting protrusion is processed on the outer wall at one end of each soft film B, and a connecting groove is processed at the other end of each soft film B. The connecting protrusion of the outer wall of each soft film B is inserted in the connecting groove of the soft film B to form a conical sleeve, and the thickness of the connecting protrusion on the soft film B inserted in the connecting groove is the same as the wall thickness of the conical sleeve.

6. A composite material conical grid forming die according to claim 4 or 5, characterized in that: The parameter equations of the spiral ribs and the annular ribs of the silicone membrane sleeve (4) are: The parametric equation of the helix between any two points can be expressed as Among them, x, y, z represent the position parameters of any point on the spiral line, ρ represents the distance from any point on the spiral line to the origin, θ represents the angle of any point on the spiral line, and θ f and θ0 are the angular coordinates of the starting point and the end point of the conical spiral, β represents the half angle of the cone, f(θ) represents the functional relationship between the meridian coordinate and the angular coordinate, and the functions corresponding to the equiangular spiral rib, the equidistant spiral rib and the geodesic spiral rib are respectively represented by f g (θ), f l (θ) and f d (θ) indicates that its expression is The constant C0 of the geodesic spiral rib is determined by the Clairaut equation, as shown in formula (6), where e is the natural base, ρ f is the distance from the upper end point of the geodesic spiral to the origin, α f g represents the spiral angle of the geodesic spiral at the starting point, α l is the helix angle of the equiangular spiral, a is the ratio of the meridian coordinate to the angular coordinate of the equidistant spiral, and the superscripts g, l, and d represent the geodesic spiral rib, equiangular spiral rib, and equidistant spiral rib, respectively; Another spiral rib is obtained by making the above spiral symmetrical with respect to any meridian in the YOZ plane. The parametric equation of the spiral is After rotating along the center of the conical shell section, a structure with uniform distribution of spiral ribs can be obtained. When the total number of spiral ribs is n h When , the parametric equation of the i-th spiral reinforcement is Among them, θ h represents the angle between the intersection points of two consecutive spiral ribs, θ h =π / n h ; The annular reinforcement divides the upper and lower spiral reinforcement into two equal parts, then the parameter equation of the kth annular reinforcement can be expressed as Among them, 0≤θ≤2π, 2≤k≤n c -1,n c is the number of annular reinforcements.

7. A method for forming a composite material conical grid forming mold according to any one of claims 1 to 6, wherein the method is implemented according to the following steps: Step 1: Assemble the conical support seat (1), fix the upper disc with holes (2) on one end of the conical support seat (1) through a plurality of connecting and fixing parts (5), fix the lower disc with holes (3) on the other end of the conical support seat (1) through a plurality of connecting and fixing parts (5), and lay each soft film A of the silicone soft film A (6) on the outside of the conical support seat (1); Step 2: Lay the prepreg tape along the groove track of the soft film A on the silicone soft film A (6), ensure that each layer of the groove of the soft film A is laid accurately, and place the protrusions of the soft film B on the silicone soft film B (7) one by one in the corresponding grooves on the soft film A, and make the protrusions of the soft film B fit tightly with the grooves of the soft film A to form a seamless overall structure; Step 3: Place the assembled molding mold into a vacuum sealed bag and place it into a high temperature container for molding; Step 4: After the molding operation of step 3 is completed, the silicone soft film B (7) is removed, the connecting fixings (5), the upper disc with holes (2), the lower disc with holes (3) and the conical support seat (1) are removed, and the composite material conical grid is demoulded on the silicone soft film A (6). The uneven parts are carefully polished until the surface is as smooth as a mirror, and a complete composite material conical grid structure is obtained.

8. A method for forming a composite material conical grid forming mold according to claim 7, wherein the method is implemented according to the following steps: In step three, the assembled molding mold is placed in a vacuum sealed bag to isolate it from external interference. The entire sealed bag is then transferred to the autoclave for efficient and uniform hot pressing processing through precisely controlled temperature and pressure to ensure that the materials are tightly combined and reach the preset shape.

9. A method for forming a composite material conical grid forming mold according to claim 8, wherein the method is implemented according to the following steps: In step 3, when the sealed bag and the molding mold are transferred to the autoclave, they are heated and pressurized by slowly heating and pressurizing in stages to fully compact the material, eliminate internal voids, and ensure the density and quality of the final product. Finally, the temperature is slowly reduced to 80°C through the cooling stage, and attention is paid to the stability of temperature control.

10. A method for forming a composite material conical grid forming mold according to claim 7, wherein the method is implemented according to the following steps: In step three, the assembled molding mold is placed in a vacuum sealed bag, and all bubbles and impurities are thoroughly vacuumed out. The sealed bag is then transferred to a hot box to use the high temperature environment to promote the curing and molding of the material.

Images