Composite material connecting skirt forming method and mold and inner rubber core mold forming mold

Abstract

The invention discloses a composite material containing skirt forming method and mold and an inner rubber core mold forming mold. The method comprises the following steps: (1) manufacturing the forming mold, namely manufacturing an outer mold, an inner mold and the inner rubber core mold and sheathing the inner rubber core mold on the outer wall of the inner mold; (2) laying up; (3) preheating and vacuumizing the forming mold; (4) carrying out resin pretreatment; (5) injecting glue and solidifying, namely solidifying resin after glue injection, wherein the inner rubber core mold is expanded along with the increase of temperature to uniformly pressing a preform and enable the resin to fully infiltrate the preform; and (6) demolding and trimming. The forming mold structure adopts the inner rubber core mold; silicone rubber is adopted and a resin transfer molding (RTM) process is assisted to form the composite material containing skirt, and a double-sided mold is adopted, so that a product has the advantages of stable dimension, good quality consistence, controllable fiber and resin contents and the like; measures such as co-solidification and the adoption of the expandable core mold are adopted to reduce the porosity, increase the volume content of the fibers of the product and improve the mechanical property.

Description

technical field [0001] The invention relates to the molding technology of solid rocket motor shells, in particular to a molding method of a composite material connecting skirt, a mold and a rubber inner core mold molding mold thereof. Background technique [0002] The connecting skirt of the solid rocket motor casing is an integral extension of the casing, which is used to realize the connection between the missile stages or with other components. The connecting skirt needs to withstand various loads such as axial pressure, bending moment, shear, and internal pressure. The force situation is more complicated. How to simplify the molding process and improve its performance without increasing the weight of the connecting skirt is crucial to the improvement of the performance of the entire engine casing. [0003] At present, the connecting skirt of composite materials is usually formed by the "prepreg lay-up + winding" molding method. This molding method exposes the following p...

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Problems solved by technology

[0003] At present, the connecting skirt of composite materials is usually formed by the "prepreg lay-up + winding" molding method. This molding method exposes the following problems in the production process: 1) There is only one rigid male mold in the molding process, and the outer surface of the product is made of The fiber yarn is wound and pressed, and sometimes there are strangle marks, protrusions, and depressions, etc., which cannot guarantee the smoothness of the outer surface of the product, and it is difficult to guarantee the overall size of the product; 2) The resin content is controlled by manual scraping, which is more harmful to the fiber damage. Large, and the degree of scraping is not easy to control, which has a great impact on the total weight and specific impulse of the engine casing; 3) It is impossible to form a composite connecting skirt with a rib structure, and the product structure efficiency is low; 4) The fiber at the corner of the connecting skirt It is easy to be overhead, delaminated and wrinkled. At present, a conservative design method with an increased safety factor is used to ensure that there is no damage under the working load, but this method further reduces the structural efficiency of the composite skirt, etc.

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