Die and method for manufacturing curved rotating surface annular long fiber unidirectional cloth

Abstract

The mold comprises an inner mold and an outer mold, the inner mold and the outer mold are each of a curved surface structure, the molded surface of the outer mold is larger than that of the inner mold, the outer mold is arranged on the outer side of the inner mold in a sleeving mode, the inner mold and the outer mold are clamped at the small end of the curved surface to form a plug, and the inner mold and the outer mold are opened at the large end; and a gap between the inner mold and the outer mold forms a space for winding reinforcement yarns. The manufacturing process is simple, and winding, gum dipping and curing shaping of the curved surface can be completed only through a simple mold. The reinforcing effect is good, all the fibers are shaped annular fibers, micro-bending of the fibers is avoided, and weight gain is little after use.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a mold and manufacturing method for manufacturing unidirectional long-fiber fabric with curved rotating surfaces. Background Technology

[0002] In the field of composite material high-pressure vessel manufacturing, due to limitations in fiber winding technology, the fibers in the head region are mainly arranged along the warp (axial) direction, lacking the circumferential fibers necessary to resist internal pressure, resulting in a significantly lower inherent strength than the body. To address this issue, the following methods have been adopted: 1. Local thickening: adding extra layers of fiber winding in the head region, typically by laying several layers of helical fibers; 2. Designing sufficiently large and thick metal pole rings or flanges; 3. Overlay reinforcement: near-circumferentially winding glass fiber or carbon fiber tapes on the outside of the head; 4. Inner lining reinforcement: additionally laying chopped fiber mat or orthogonal fabric on the inner wall of the head. In practical applications, multiple reinforcement methods are often combined. In the winding of solid rocket motor combustion chamber shells, inner lining reinforcement is most commonly used, as it adds the least weight. Current practices involve cutting carbon fiber cloth into fan-shaped sections, applying adhesive to the head area, and then winding fibers on the outer surface. A more advanced approach is to use a special weaving method to create a hyperboloidal special fabric that can tightly adhere to the head for inner lining reinforcement. However, this type of fabric is very difficult and inefficient to weave, making it unsuitable for small to medium batch production. Summary of the Invention

[0003] The purpose of this invention is to provide a mold and manufacturing method for manufacturing unidirectional long-fiber fabric with a curved rotating surface, so as to solve the above-mentioned problems.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: The mold used to manufacture unidirectional long-fiber fabric with curved rotating surface includes an inner mold and an outer mold. Both the inner mold and the outer mold are curved structures. The outer mold has a larger surface area than the inner mold and is fitted outside the inner mold. The inner mold and the outer mold are locked at the small end of the curved surface to form a blockage and open at the large end. The gap between the inner mold and the outer mold forms a space for the reinforcing yarn to wind.

[0005] Furthermore, the curved surface structure is consistent with the contact surface of the end cap to be reinforced.

[0006] Furthermore, the outer mold is provided with a set of holes or narrow slots for observing or trimming the fibers and resin impregnation that have been wound into the mold cavity.

[0007] Furthermore, several inner mold oblique grooves are provided on the inner mold, and several outer mold oblique grooves are provided on the outer mold.

[0008] Furthermore, the inner mold oblique groove and the outer mold oblique groove rotate in opposite directions.

[0009] Furthermore, resin impregnation is applied to the grooves of the inner mold oblique groove and the outer mold oblique groove.

[0010] Furthermore, the inner mold and the outer mold are fixed at the small end of the curved surface by nuts.

[0011] A method for manufacturing a circumferential long-fiber unidirectional fabric with a curved rotating surface includes the following steps: Carbon fiber is wound into the cavity between the inner and outer molds; Evenly drip resin into the spiral narrow slots of the inner and outer molds using a needle; The resin is squeezed into the fiber and spread on the surface of the fiber due to surface tension when it is placed in a vacuum chamber and vacuumed. Heat and cure, then open the mold and remove the product.

[0012] The curved rotating surface circumferential long fiber unidirectional fabric is prepared based on the manufacturing method of the curved rotating surface circumferential long fiber unidirectional fabric.

[0013] Compared with the prior art, the present invention has the following technical effects: The manufacturing process of this invention is simple, requiring only a simple mold to complete the winding, impregnation, and curing of the curved surface.

[0014] This invention has a good reinforcing effect, as all fibers are shaped ring fibers without any micro-bending, resulting in high fiber strength utilization and minimal weight gain after use. Attached Figure Description

[0015] Figure 1 This is a longitudinal cross-sectional schematic diagram of the fabrication process of a curved rotating surface circumferential long fiber unidirectional fabric for end cap reinforcement. Wherein: 1—inner mold, 2—outer mold, 3—nut, 4—inner mold oblique groove, 5—outer mold oblique groove, 6—yarn, 7—curved rotating surface unidirectional fabric. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] Example 1: See Figure 1 A type of curved rotating surface circumferential long fiber unidirectional fabric for end cap reinforcement is described. The carbon fibers are wound into the required size in a mold using a winding method, followed by unsaturated vacuum impregnation and curing. The required mold consists of two molds, inner and outer. The curved surface of the inner mold 1 matches the contact surface of the end cap to be reinforced, while the outer mold 2 is slightly larger than the inner mold. The inner and outer molds are locked at the small end to form a seal, and open at the large end. The gap between the inner and outer molds provides the space for the reinforcing yarn to wind. Reverse spiral narrow grooves are created on the inner mold to observe and correct the fiber winding and to apply resin.

[0020] Production steps: 1. Wind carbon fiber into the cavity between the inner and outer molds; 2. Use a needle to evenly drip an appropriate amount of high-temperature resistant flexible epoxy resin into the spiral narrow groove of the inner mold. 3. Clamp the mold shaft onto the shaft of the high-speed motor, then power on the motor to rotate it at high speed and use centrifugal force to make the adhesive quickly penetrate into the fiber; 4. Heat curing; 5. Open the mold and remove the product.

[0021] Due to the limited amount of adhesive applied, the fibers will not be saturated, but all fibers will be basically soaked. However, the gaps between the fibers cannot be fully filled. The cured blank will have a large number of tiny gaps on both the surface and inside, providing a large number of anchor points for subsequent adhesive application.

[0022] In use, resin is first applied to both the inner and outer surfaces of the reinforcing curved rotating surface unidirectional fabric produced by this invention, and then it is applied to the end cap of the combustion chamber shell being wound, followed by continued winding. Adding several layers of curved rotating surface unidirectional fabric to the end cap of the wound shell can significantly improve the circumferential strength of the end cap winding.

[0023] Example 2: A curved, rotating, circumferential long-fiber unidirectional fabric for end cap reinforcement is produced by winding carbon fibers to the required dimensions in a mold using a winding method, followed by unsaturated vacuum impregnation and ice-curing for shaping. The required mold consists of two parts: an inner mold whose curved surface aligns with the surface of the end cap to be reinforced, and an outer mold slightly larger than the inner mold. The inner and outer molds are locked at their smaller ends, forming a seal, while remaining open at their larger ends. The gap between the inner and outer molds provides the space for the reinforcing yarn winding. A set of small through-holes (￠3~￠5) are machined at regular intervals on the cavity surface of the outer mold 2 for observing and correcting fiber winding and for applying resin.

[0024] Production steps: 1. Wind carbon fiber into the cavity between the inner and outer molds; 2. Use a needle to evenly drip an appropriate amount of high-temperature resistant flexible epoxy resin into the spiral narrow groove of the inner and outer molds. 3. Place it in a vacuum chamber and evacuate it. The adhesive will then quickly penetrate into the fiber and spread on the surface of the fiber due to surface tension. 4. Heat curing; 5. Open the mold and remove the product.

[0025] Due to the limited amount of adhesive applied, the fibers will not be saturated, but more than half of them will be impregnated, ensuring that none of the fibers will scatter after heat curing without strong intervention. Because the gaps between the fibers cannot be fully filled, although the cured blank binds the fibers wrapped in the mold cavity together, numerous tiny gaps remain both on the surface and inside, providing ample anchor points for subsequent adhesive application. Because the inner and outer molds are respectively made with spiral narrow slots rotating in opposite directions, although the amount of adhesive is limited and cannot completely impregnate the fibers in the gun, the intersection of the spiral narrow slots on the inner and outer molds can be completely impregnated, forming a relatively strong connection.

[0026] In use, resin is first applied to both the inner and outer surfaces of the reinforcing curved rotating surface unidirectional fabric produced by this invention, and then it is applied to the end cap of the solid-state combustion chamber shell being wound, followed by continued winding. Adding several layers of curved rotating surface unidirectional fabric to the end cap of the wound shell can significantly improve the circumferential strength of the end cap winding body.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface, characterized in that, It includes an inner mold (1) and an outer mold (2). Both the inner mold (1) and the outer mold (2) are curved structures. The outer mold (2) has a larger surface than the inner mold (1). The outer mold (2) is fitted on the outside of the inner mold (1). The inner mold (1) and the outer mold (2) are locked at the small end of the curved surface to form a blockage, and open at the large end. The gap between the inner mold (1) and the outer mold (2) forms a space for the reinforcing yarn to wind.

2. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 1, characterized in that, The curved surface structure is consistent with the mating surface of the head to be reinforced.

3. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 1, characterized in that, The outer mold (2) is provided with a set of holes or narrow slots for observing or trimming the fibers wrapped into the mold cavity and the impregnation with glue.

4. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 1, characterized in that, Several inner mold oblique grooves (4) are provided on the inner mold (1), and several outer mold oblique grooves (5) are provided on the outer mold (2).

5. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 4, characterized in that, The inner mold oblique groove (4) and the outer mold oblique groove (5) have opposite rotation directions.

6. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 4, characterized in that, Apply resin impregnation to the grooves of the inner mold oblique groove (4) and the outer mold oblique groove (5).

7. The mold for manufacturing unidirectional long-fiber fabric with a curved rotating surface according to claim 1, characterized in that, The inner mold (1) and the outer mold (2) are fixed at the small end of the curved surface by a nut (3).

8. A method for manufacturing a circumferential long-fiber unidirectional fabric with a curved rotating surface, characterized in that, The mold for manufacturing curved rotating surface circumferential long fiber unidirectional fabric according to any one of claims 1 to 7 includes the following steps: Carbon fiber is wound in the cavity between the inner mold (1) and the outer mold (2); Resin is evenly dripped into the spiral narrow grooves of the inner mold (1) and the outer mold (2) using a needle; The resin is squeezed into the fiber and spread on the surface of the fiber due to surface tension when it is placed in a vacuum chamber and vacuumed. Heat and cure, then open the mold and remove the product.

9. A circumferential long-fiber unidirectional fabric with a curved rotating surface, characterized in that, It is prepared based on the manufacturing method of the curved rotating surface circumferential long fiber unidirectional fabric according to claim 8.

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