Automatic laying and winding forming die and forming process method for composite material grid structure
By designing an automated layup and winding molding die and molding process for composite material mesh structures, the problems of unstable fiber tension and uneven unfolding of prepreg narrow strips were solved, achieving efficient molding and cost reduction of mesh structures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-03-24
AI Technical Summary
In existing technologies, the fiber tension is unstable in manual lay-up processes, and the prepreg narrow strips are unevenly unfolded and there is significant waste at the pin hangers in automatic winding processes, resulting in low mechanical properties and high costs for composite mesh structures.
An automated layup and winding mold with a composite material mesh structure is used, including a mesh outer mold, a support core mold, a process end cap, and a guide block. Through the design of external hanging needles, internal hanging needles, and guide blocks, combined with an automated layup and winding device, continuous winding and precise positioning of prepreg narrow strips are achieved, reducing fiber waste.
It achieves continuous and precise layup of composite material mesh structures, improves mechanical properties, reduces structural defects and fiber waste, and lowers manufacturing costs.
Smart Images
Figure CN121716337A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of composite material structure manufacturing, and relates to an automatic laying and winding forming die and a forming process method of a composite material grid structure. BACKGROUND
[0002] The grid load-bearing cylinder is a hollow grid cylinder composed of spiral ribs and hoop ribs of different widths, as shown in FIG. 1, and has the advantages of lightweight and high load-bearing. The spiral ribs and hoop ribs are composed of thin-layer fiber prepreg narrow strips stacked and crossed, and are formed by layer-by-layer accumulation. The prepreg narrow strips used for laying have specifications such as 2 mm, 3 mm and 6 mm in width. Conventional forming methods include manual laying process and automatic winding process, but both of them have limitations. The manual laying process has good adaptability to the structure shape and can adapt to different grid configurations, but the prepreg narrow strips laid by hand have no tension or unstable tension, and the fibers cannot maintain a stable tension state, and local defects such as buckling may occur, so that the mechanical properties of the fibers cannot be fully utilized, and the mechanical properties of the workpiece are low. The automatic winding process can ensure constant tension winding of the fibers, and the fibers in the formed workpiece are in a tension state, which maximizes the mechanical properties of the fibers. However, the current winding method has deficiencies in the winding die and the forming process. First, the winding process cannot ensure that the prepreg narrow strips are fully unfolded in the die groove. During the winding process, the prepreg narrow strips are in a suspended state, and the drop point cannot be accurately controlled. Moreover, as the layers accumulate, the drop point also changes. The prepreg narrow strips interfere with the side of the die groove, resulting in uneven unfolding width of the prepreg narrow strips, and defects of the rib after solidification. Second, the conventional die head single needle hanging method cannot be used. As the layers accumulate at the hanging needle (equivalent to the hanging needle becoming thicker), the prepreg narrow strips gradually deviate from the original designed trajectory, and cannot be aligned with the die groove, making it difficult for the prepreg narrow strips to enter the groove. Third, in order to fully unfold the prepreg narrow strips before entering the groove, a large angle winding is usually used at the head, that is, after the prepreg narrow strips come out of an outer hanging needle, the die is rotated by 120° or more and directly enters the next outer hanging needle, resulting in a large amount of waste of high-value fibers and increased cost of the workpiece. Figure 1 SUMMARY
[0003] The technical problem solved by the present application is to overcome the deficiencies of the prior art and provide an automatic laying and winding forming die and a forming process method of a composite material grid structure.
[0004] The technical solution of the present application is as follows: The automatic laying and winding forming die of the composite grid structure comprises a grid outer die, a supporting core die, a process head, and an extension shaft; the supporting core die is in a columnar structure, the grid outer die is sleeved on the supporting core die, and the grid outer die is connected with the supporting core die through positioning screw pins; a plurality of helical rib grooves and annular rib grooves are processed on the grid outer die, a grid outer die segment on the supporting core die is a product segment, the helical rib grooves on the surface of the product segment form grid recesses, and the configuration of the grid recesses is consistent with the configuration of a grid force bearing cylinder; The extension shafts are fixedly connected with the two ends of the supporting core die, and the extension shafts are coaxial with the supporting core die; The process head comprises an end ring, outer hanging needles, inner hanging needles, and guide blocks; the end ring is installed at the two ends of the supporting core die, the outer hanging needles and the inner hanging needles are both installed on the end ring, each outer hanging needle is located at the outlet of a helical rib and is perpendicular to the axis of the supporting core die, the number of the outer hanging needles is consistent with the number of the helical ribs, the inner hanging needles are perpendicular to the end surface of the supporting core die, the number of the inner hanging needles is half of the number of the outer hanging needles, and the inner hanging needles are installed between every two adjacent outer hanging needles; the part of the grid outer die, which is not installed with the supporting core die at the two ends, is recorded as a process segment; a plurality of guide blocks are uniformly distributed on each process segment, and the number of the guide blocks is consistent with the number of the helical ribs, so as to guide the trajectory of the pre-impregnated narrow band.
[0005] Preferably, the end head of the outer hanging needle is outwardly inclined by 45°, the outer hanging needle is bent at the contact position of the outer hanging needle and the supporting core die, the pre-impregnated towpreg can slide to the root during winding, and the influence of the accumulated thickening of the pre-impregnated towpreg is reduced.
[0006] Preferably, each outer hanging needle is located at the outlet of a helical rib and is staggered by one rib groove width of the helical rib outlet.
[0007] Preferably, one inner hanging needle is arranged between every two adjacent outer hanging needles, the inner hanging needle is perpendicular to the outer hanging needle, the division circle of all the inner hanging needles is smaller than the outer diameter of the supporting core die, and the included angle formed by the pre-impregnated towpreg from the outer hanging needle to the inner hanging needle and then to the outer hanging needle is not greater than 120°.
[0008] Preferably, the inner hanging needle is located at the end surface and is inclined by 45° to the center of the end surface, the pre-impregnated towpreg can slide to the root during winding, and the influence of the accumulated thickening of the pre-impregnated towpreg is reduced.
[0009] Preferably, each guide block is designed as a horn mouth structure, the large opening side of the horn mouth structure faces the outer hanging needle, and the small opening side of the horn mouth structure corresponds to the grid recess of the die.
[0010] Preferably, the grid outer die is connected with the supporting core die through the positioning screw pins.
[0011] The forming process method realized by the automatic laying and winding forming die of the composite grid structure comprises the following steps. S1, assembling the forming die; S2. Using an automatic laying and winding device, starting from the external hanging needle, the high-strength carbon fiber of all the spiral ribs of the load-bearing cylinder is wound sequentially according to the set tension, and the mesh soft mold is tightly fixed on the support core mold. S3. Replace the high-strength carbon fiber with satellite-specific high-modulus carbon fiber prepreg narrow tape, reset the tension, and start winding from the external pin on one side of the support mandrel using an automatic laying and winding device. S4. After passing through the process section and guide block in sequence, when winding to the product section, switch to automatic laying mode and start laying along the spiral rib groove. When the pre-impregnated narrow strip exits the product section, switch to automatic winding mode for winding. After passing through the guide block and process section on the other side of the support core mold, change direction through the outer hanging pin, hang the inner hanging pin, change direction again, and hang the next outer hanging pin. S5. Repeat step S4 until all spiral reinforcements are laid. S6. After the spiral reinforcement is laid, wrap the circumferential reinforcement in a winding pattern as follows: The circumferential ribs are circular in shape, and the grooves of the circumferential ribs are connected to the grooves of the spiral ribs. During winding, the prepreg narrow tape enters the groove of the spiral rib from the side of the external pin, turns at the intersection of the spiral rib groove and the circumferential rib groove, and becomes a 90° winding. After winding one circumferential rib, the prepreg narrow tape turns again at the intersection of the circumferential rib groove and the spiral rib groove, and becomes a spiral winding. It then enters the next circumferential rib groove through the spiral rib groove. The above process is repeated until all circumferential ribs are wound in sequence. Finally, it reaches the external pin at the other end through the spiral rib groove, completing one layer of circumferential rib winding. The above process is repeated until the required layup thickness is achieved. After the product has cured, the process sections at both ends are cut off to obtain the mesh load-bearing cylinder.
[0012] The advantages of this invention compared to the prior art are: (1) The automatic laying and winding molding mold and molding process of composite material grid structure adopted in this invention solves the problem of continuous and accurate laying and molding of grid load-bearing cylinder. That is, the prepreg tow is turned at the end cap by winding, so as to maintain the continuity of the fiber and keep the tension on the fiber. The prepreg narrow strip is accurately positioned, stacked and compacted in the mold groove by laying, which improves the mechanical properties of the grid structure and reduces structural defects.
[0013] (2) The automatic laying and winding molding mold and molding process of composite material mesh structure adopted in this invention solves the problem that the prepreg narrow strip is difficult to enter the groove due to the accumulation of prepreg narrow strip at the hanging needle during the winding process. At the same time, the design of the inner hanging needle shortens the waste length of the fiber in the process section, which is beneficial to reduce the manufacturing cost. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of a grid-supported cylinder. Figure 2 This is a schematic diagram of the mold head; Figure 3 This is a schematic diagram of trajectory division; Figure 4 This is a schematic diagram of the trajectory path; Figure 5 This is a schematic diagram of the head trajectory; Figure 6 This is a schematic diagram of the guide block. Detailed Implementation
[0015] The invention will now be further described with reference to the accompanying drawings.
[0016] like Figure 2 As shown, the grid structure forming mold of the present invention includes a grid outer mold 6, a supporting core mold 5, a guide block 7, a process end cap 1, and an extension shaft 3. The supporting core mold 5 is a columnar structure, and the grid outer mold 6 is fitted onto the supporting core mold 5. The grid outer mold is connected to the supporting core mold by positioning pins. The grid outer mold 6 is machined with several spiral rib grooves and circumferential rib grooves. The grid outer mold segment on the supporting core mold is the product segment. The spiral rib grooves on the surface of the product segment form a grid groove. After the grid outer molds are assembled, the grid groove configuration of the cylindrical product segment is consistent with the configuration of the grid load-bearing cylinder. The extension shaft is connected to both ends of the supporting core mold by screws, and the extension shaft is coaxial with the supporting core mold. The process end cap is annular and is installed at both ends of the supporting core mold by screws. The guide block is installed on the cylindrical surface of the supporting core mold by screws.
[0017] The process head comprises two layers of pins, consisting of an end ring, an outer pin 2, and an inner pin 4. Each outer pin is located at the exit of the spiral rib, perpendicular to the cylindrical surface of the supporting mandrel. The end of the outer pin is inclined outward at 45° and offset from the spiral rib exit by one groove width to avoid blocking the exit of the prepreg narrow strip. The number of outer pins on each process head is the same as the number of spiral ribs. The inner pins are perpendicular to the end face of the supporting mandrel, and their number is half that of the outer pins. The inner pins are located between two adjacent outer pins.
[0018] The sections of the outer grid mold 6 without supporting core molds at both ends are designated as process sections, such as... Figure 3 As shown. Figure 6 As shown, guide blocks are set in both process sections. The guide blocks are connected to the supporting core mold by screws. The number of guide blocks is the same as the number of spiral ribs. The guide blocks are designed with a flared structure. The large opening side of the guide block hangs the pins outward, and the small opening side corresponds to the grid groove of the mold. When winding and laying, the guide blocks can assist the prepreg narrow strip into the grid groove mold. At the same time, it can avoid the prepreg narrow strip trajectory deviation caused by the accumulation of prepreg narrow strip at the pin hanging point, and solve the problem that the prepreg narrow strip cannot be accurately put into the groove as the layup increases.
[0019] The outer pin bends at the contact point with the supporting mandrel, allowing the prepreg yarn to slide to the root during winding, thus reducing the impact of cumulative thickness increase in the prepreg yarn. An inner pin is positioned between two adjacent outer pins, perpendicular to the outer pins. The pitch circle of all inner pins is smaller than the outer diameter of the supporting mandrel, and the angle formed by the prepreg yarn from the outer pin, through the inner pin, and back to the outer pin is no greater than 120°. The inner pin is located on the end face and inclined at 45° towards the center of the end face circle, allowing the prepreg yarn to slide to the root during winding, further reducing the impact of cumulative thickness increase in the prepreg yarn.
[0020] In the aforementioned layup and winding process, the prepreg narrow strip is continuous and the fibers are not cut. The product section uses an automatic layup mode, where the prepreg narrow strip is accurately positioned by the layup head. The process section and process end cap section use an automatic winding mode to allow the prepreg narrow strip to change direction at the process end cap. The reason for switching between automatic layup and automatic winding is that the prepreg narrow strip is laid using a narrow layup roller of the same width as the prepreg narrow strip so that it can enter the groove of the grid mold and compact the layup. However, when the narrow roller exits the mold groove and changes direction, the prepreg narrow strip will slip off the layup roller, causing layup failure. Therefore, when the narrow roller exits the mold groove, it switches to the automatic winding function. The winding roller is a wide roller, generally wider than 50mm, and is a waist-shaped roller that is thick at both ends and thin in the middle. When the layup direction of the prepreg narrow strip is changed by the hanging pin, the prepreg narrow strip can always be kept on the winding roller.
[0021] After the winding of the process section and the process end cap section is completed, the automatic laying and winding device switches back to automatic laying mode, and the narrow pressure roller enters the grid groove to start laying.
[0022] The single laying and winding trajectory begins with the outer pin of the process head, passes sequentially through the process section, guide block, and spiral groove of the mesh mold, enters the guide block and process section on the other side of the supporting core mold, changes direction via the outer pin, attaches an inner pin, changes direction again, attaches the next outer pin, changes direction again, completes one basic trajectory unit, and prepares to enter the next trajectory unit, as follows. Figure 4 As shown. The trajectory of the end cap is as follows. Figure 5 As shown.
[0023] The described prepreg narrow strip trajectory requires a transition from an outer hanging pin to an inner hanging pin, and then to the next outer hanging pin, involving three direction changes. This method ensures that the prepreg narrow strip can fully unfold without deformation on the surface section of the cylindrical mold. Conventionally, when the prepreg narrow strip changes direction via the hanging pin, it tends to bunch up at the pin location, and this deformation extends into the product area, causing defects in the mesh structure ribs. This invention, through the inner hanging pin, ensures that the most severe deformation of the prepreg narrow strip occurs at the inner hanging pin. Under tension, the prepreg narrow strip adheres tightly to the annular surface of the process head and flattens out, resulting in only slight deformation at the outer hanging pin and reducing the width error of the prepreg narrow strip entering the mesh groove.
[0024] Before the automatic laying and winding of the grid support cylinder, wear-resistant high-strength fiber is first selected. The winding module of the automatic laying and winding device uses high tension to wind the material onto the mold surface, covering all the spiral ribs and circumferential ribs. This makes the flexible mold with grid grooves fit tightly and uniformly on the support core mold. The high tension can make the grid units evenly distributed.
[0025] The grid-supported cylinder consists of spiral reinforcement, circumferential reinforcement, end frames, etc., such as Figure 1 As shown. The molding process is as follows: First, a grid molding mold is prepared. The surface of the mold has pre-made grid grooves. The shape of the grooves is consistent with the grid configuration of the grid load-bearing cylinder. The grid configurations at both ends of the grid load-bearing cylinder are extended as process sections. The length of the process sections on both sides is more than 100mm. Prepreg narrow strip turning heads are set at both ends of the grid cylindrical mold. An automatic laying and winding device is used to lay and wind the prepreg narrow strip into the groove of the mold. The prepreg narrow strip is always kept continuous and stacked layer by layer until the required layup thickness is reached. After the product is cured, the process sections at both ends are cut off to obtain the grid load-bearing cylinder.
[0026] Example: Method for forming a monofilament bundle mesh load-bearing cylinder using the mold of the present invention: The mold is assembled in place, the external and internal pins and guide blocks are installed in place, and the mesh outer mold is installed in place; Switch the automatic laying and winding device to winding mode. At this time, the winding roller is a 50mm wide drum-shaped wide roller, and the 6mm wide fiber bundle is located in the middle of the winding roller. The tension is set to 40N. The winding start point is at the hanging needle. T700 grade high-strength carbon fiber is wound with this tension to complete one layer of winding of all the spiral ribs of the grid support cylinder. The grid soft mold is tightly fixed on the support core mold. Replace the T700 grade high-strength carbon fiber with M55J grade high-modulus carbon fiber prepreg narrow tape, set the tension to 10N, and start winding from the external hanging needle. After the yarn drop point of the prepreg narrow tape passes the guide block, the automatic laying and winding device switches to the laying mode, and replace the winding roller with the laying roller. The laying roller is the same width as the prepreg narrow tape, with a width of 6mm. The automatic laying and winding device presses down radially along the mold, and the pressure roller presses the prepreg narrow tape firmly into the mold groove to start laying. When exiting the product section, switch back to the automatic winding mode and repeat the cycle to complete one laying of all the spiral ribs. After laying the spiral reinforcement, the circumferential reinforcement is wound in a winding pattern. The prepreg narrow tape enters the spiral reinforcement groove from the side of the external pin, turns at the intersection of the spiral reinforcement groove and the circumferential reinforcement groove, and becomes a 90° winding. After winding one circumferential reinforcement, the prepreg narrow tape turns again at the intersection of the circumferential reinforcement groove and the spiral reinforcement groove, becoming a spiral winding, and enters the next circumferential reinforcement groove through the spiral reinforcement groove. The above steps are repeated to wind all the circumferential reinforcements in sequence. Finally, it reaches the external pin at the other end through the spiral reinforcement groove, completing one layer of circumferential reinforcement winding. The spiral reinforcement and circumferential reinforcement layers are alternately laid up in sequence until the completion. After the product has cured, the process sections at both ends are cut off to obtain the mesh load-bearing cylinder.
[0027] The contents not described in detail in this specification are common knowledge to those skilled in the art.
Claims
1. An automatic layup and winding mold for composite material mesh structures, characterized in that: It includes a mesh outer mold (6), a support core mold (5), a process end cap (1), and an extension shaft (3); the support core mold (5) is a columnar structure, and the mesh outer mold (6) is fitted on the support core mold (5) and connected to the support core mold by a positioning screw; the mesh outer mold (6) is machined with several spiral rib grooves and circumferential rib grooves, and the mesh outer mold section on the support core mold is the product section. The spiral rib grooves on the surface of the product section form a mesh groove, and the mesh groove configuration is consistent with the configuration of the mesh load-bearing cylinder; Both ends of the support core mold are fixedly connected to the extension shaft (3), and the extension shaft is coaxial with the support core mold; The process end cap includes an end ring, an outer pin (2), an inner pin (4), and a guide block (7). The end ring is installed at both ends of the support core mold. The outer pin (2) and the inner pin (4) are both installed on the end ring. Each outer pin is located at the outlet of the spiral rib and is perpendicular to the axis of the support core mold. The number of outer pins is the same as the number of spiral ribs. The inner pin is perpendicular to the end face of the support core mold and is half the number of outer pins. An inner pin is installed between every two adjacent outer pins. The part of the grid outer mold (6) where the support core mold is not installed is called the process section. Several guide blocks (7) are evenly distributed on each process section. The number of guide blocks is the same as the number of spiral ribs. They are used to guide the prepreg narrow strip trajectory.
2. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: The tip of the external needle is tilted outward at 45°. The external needle bends at the contact point between the external needle and the support mandrel, allowing the prepreg yarn to slide to the root during winding, thus reducing the cumulative thickening effect of the prepreg yarn.
3. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: Each external pin is located at the exit of the spiral rib and is offset from the spiral rib exit by one groove width.
4. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: One inner pin is set between two adjacent outer pins. The inner pin is perpendicular to the outer pin. The pitch circle of all inner pins is smaller than the outer diameter of the support mandrel. The angle formed by the prepreg yarn from the outer pin through the inner pin and back to the outer pin is no greater than 120°.
5. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: The inner hanging pin is located on the end face and is inclined at 45° toward the center of the end face. During winding, the prepreg yarn can slide to the root, reducing the impact of the cumulative thickening of the prepreg yarn.
6. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: Each guide block is designed with a flared structure, with the larger opening facing the external pin and the smaller opening corresponding to the mold grid groove.
7. The automatic layup and winding mold for a composite material mesh structure according to claim 1, characterized in that: The outer grid mold (6) is connected to the supporting core mold by positioning screws.
8. A molding process method using an automated layup and winding mold for a composite material mesh structure as described in any one of claims 1-7, characterized in that, include: S1, Assembly molding mold; S2. Using an automatic laying and winding device, starting from the external hanging needle, the high-strength carbon fiber of all the spiral ribs of the load-bearing cylinder is wound sequentially according to the set tension, and the mesh soft mold is tightly fixed on the support core mold. S3. Replace the high-strength carbon fiber with satellite-specific high-modulus carbon fiber prepreg narrow tape, reset the tension, and start winding from the external pin on one side of the support mandrel using an automatic laying and winding device. S4. After passing through the process section and guide block in sequence, when winding to the product section, switch to automatic laying mode and start laying along the spiral rib groove. When the pre-impregnated narrow strip exits the product section, switch to automatic winding mode for winding. After passing through the guide block and process section on the other side of the support core mold, change direction through the outer hanging pin, hang the inner hanging pin, change direction again, and hang the next outer hanging pin. S5. Repeat step S4 until all spiral reinforcements are laid. S6. After the spiral reinforcement is laid, wrap the circumferential reinforcement in a winding pattern as follows: The circumferential ribs are circular in shape, and the grooves of the circumferential ribs are connected to the grooves of the spiral ribs. During winding, the prepreg narrow tape enters the groove of the spiral rib from the side of the external pin, turns at the intersection of the spiral rib groove and the circumferential rib groove, and becomes a 90° winding. After winding one circumferential rib, the prepreg narrow tape turns again at the intersection of the circumferential rib groove and the spiral rib groove, and becomes a spiral winding. It then enters the next circumferential rib groove through the spiral rib groove. The above process is repeated until all circumferential ribs are wound in sequence. Finally, it reaches the external pin at the other end through the spiral rib groove, completing one layer of circumferential rib winding. The above process is repeated until the required layup thickness is achieved. After the product has cured, the process sections at both ends are cut off to obtain the mesh load-bearing cylinder.