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CN-122008589-A - Large-size high-strength heat-proof rocket end cap and manufacturing method thereof

CN122008589ACN 122008589 ACN122008589 ACN 122008589ACN-122008589-A

Abstract

The invention relates to the technical field of rocket manufacturing, and discloses a large-size high-strength heat-proof rocket end cap and a manufacturing method thereof. The method adopts low-volatile hot-melt phenolic resin impregnated fiber prepreg as a raw material, and reduces the internal gas retention risk in the forming process by paving and actively constructing an interlayer exhaust channel and an intermittent compaction process lower than the resin gel temperature in stages under the condition of a single-sided die, and is matched with a multi-layer collaborative exhaust packaging structure and a vacuum bag in the curing stage so as to effectively exhaust residual gas in the product under the pressure. The low-porosity molding of the large-size thick-wall rocket end cap is realized through the cooperative design of a material system and the paving, exhausting, compacting and curing processes, and the method is suitable for manufacturing the large-size heat-proof composite end cap with complex configuration.

Inventors

  • CHEN ZHENGHUI
  • LI YI
  • FENG GUANGLIANG
  • WANG PENG

Assignees

  • 安徽梦克斯航空科技有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (9)

  1. 1. The manufacturing method of the large-size high-strength heat-proof rocket end cap is characterized by comprising the following steps of: a) Preparing raw materials, namely selecting a prepreg made of low-volatile hot-melt phenolic resin impregnated fiber fabric as a molding raw material; b) Paving and shaping, namely paving the prepreg on a single-sided die (1) according to a preset paving sequence to form an end cap preform (2); c) Carrying out gas discharge treatment on the paved multi-layer prepreg structure periodically in the paving process to form a gas discharge channel structure for communicating layers inside the prefabricated body (2), and carrying out intermittent compaction under the condition of being lower than the gel temperature of the hot-melt phenolic resin in the process of gradually increasing the thickness of the prefabricated body (2) so as to attach the layers and promote gas discharge; d) The surface of the prefabricated body (2) after the paving is completed is sequentially provided with a demoulding layer (3), an exhaust control layer and an air permeable layer to form a multi-layer cooperative exhaust structure, and the multi-layer cooperative exhaust structure is covered with a vacuum bag (7) for vacuum sealing and then placed in a pressure curing environment to complete curing and forming, so that the large-size high-strength heat-proof rocket end cap is manufactured; wherein the exhaust control layer comprises at least a porous isolation layer (4) and a directional ventilation layer (5), and the ventilation layer can comprise a ventilation felt layer (6).
  2. 2. The method of manufacture of claim 1 wherein the hot melt phenolic resin is a solvent-free hot melt phenolic resin system that produces less volatile components during curing than solvent-based phenolic resin systems.
  3. 3. The manufacturing method according to claim 1, wherein the exhaust passage structure is formed by performing a partial penetration process, a partial removal process, and/or a molding interval process on the laid-down multi-layered prepreg structure to shorten the exhaust path of the gas inside the preform (2).
  4. 4. The method of claim 1 wherein the intermittent compaction is at a temperature below the gel temperature of the hot melt phenolic resin such that the resin is in a flowable but uncured state.
  5. 5. The method of manufacturing as claimed in claim 1 or 4, wherein said intermittent compaction is achieved by heat in conjunction with vacuum or external pressure.
  6. 6. The method of manufacture of claim 1, wherein the multi-layered co-venting structure comprises at least a porous barrier layer (4) and a directional venting layer (5), and may further comprise a venting felt layer (6) for pressure equalization or auxiliary venting, wherein: The porous isolation layer (4) is used for limiting resin migration; The directional ventilation layer (5) is used for guiding gas to be discharged to a vacuum channel.
  7. 7. The method of manufacturing according to claim 1, characterized in that the single-sided mould (1) is a female or male mould.
  8. 8. A large-size high-strength heat-proof rocket end cap produced by the production method according to any one of claims 1 to 7.
  9. 9. A large-size high-strength heat-proof rocket end cap according to claim 8, wherein said end cap is of a multi-layer composite structure, and an exhaust passage structure for communicating between layers is provided inside.

Description

Large-size high-strength heat-proof rocket end cap and manufacturing method thereof Technical Field The invention relates to the technical field of rocket manufacturing, in particular to a head cap for a carrier rocket and a manufacturing method thereof, and especially relates to a manufacturing process of an integrated composite material with low porosity and heat insulation suitable for large-size and complex-configuration head caps. Background The end cap is used as the forefront part of the carrier rocket, and needs to bear pneumatic heating scouring and mechanical load, and the material is required to have the characteristics of high strength, heat insulation, low density and the like. The mainstream technical proposal in the field at present generally adopts a high silica glass fiber cloth/ammonia phenolic solvent method prepreg system, and reduces volatile components and porosity through high-temperature hot compaction. However, in larger-size, thicker-wall end cap products, the number of hot pressing times is high, the hot pressing temperature is often high, the resin is easy to gel too early, the subsequent paving and final curing quality is affected, and a low-porosity product is difficult to obtain stably under the single-sided die autoclave process condition. Disclosure of Invention The invention aims to provide a large-size high-strength heat-proof rocket end cap and a manufacturing method thereof, and the low-porosity molding of the large-size thick-wall end cap is realized through the material system selection, active exhaust in the paving stage, low-temperature intermittent compaction and a cooperative exhaust packaging structure. In order to achieve the above purpose, the present invention adopts the following technical scheme: a manufacturing method of a large-size high-strength heat-proof rocket end cap comprises the following steps: a) Preparing raw materials, namely selecting a prepreg made of low-volatile hot-melt phenolic resin impregnated fiber fabric as a molding raw material; b) Paving and molding, namely paving the prepreg on a single-sided die according to a preset paving sequence to form an end cap preform; c) Performing staged exhaust and compaction, namely performing exhaust treatment on the paved multi-layer prepreg structure periodically in the paving process to form an exhaust channel structure used for communicating layers in the prefabricated body, and performing intermittent compaction under the condition of being lower than the gel temperature of the hot-melt phenolic resin in the process of gradually increasing the thickness of the prefabricated body so as to attach the layers and promote gas discharge; d) The surface of the prefabricated body after the paving is finished is sequentially provided with a demoulding layer, an exhaust control layer and an air permeable layer to form a multilayer cooperative exhaust structure, and the multilayer cooperative exhaust structure is covered with a vacuum bag for vacuum sealing and then placed in a pressure curing environment to finish curing and forming, so that the large-size high-strength heat-proof rocket end cap is manufactured; wherein, the exhaust control layer includes at least a porous isolation layer and a directional ventilation layer, and the ventilation layer may include a ventilation felt layer. Preferably, the hot melt phenolic resin is a solvent-free hot melt phenolic resin system that produces less volatile components during curing than solvent-based phenolic resin systems. Preferably, the exhaust passage structure is formed by performing a partial penetration process, a partial removal process, and/or a molding interval process on the lay-up completed multi-layered prepreg structure to shorten the exhaust path of the gas inside the preform. Preferably, the temperature of the intermittent compaction is less than the gel temperature of the hot resole resin, leaving the resin in a flowable but uncured state. Preferably, the intermittent compaction is achieved by heat in conjunction with vacuum or external pressure. Preferably, the multi-layered co-venting structure comprises at least a porous barrier layer and a directional venting layer, and may further comprise a venting felt layer for pressure equalization or auxiliary venting, wherein: The porous isolating layer is used for limiting resin migration; The directional ventilation layer is used for guiding gas to be discharged to the vacuum channel. Preferably, the single-sided die is a female die or a male die. A large-size high-strength heat-proof rocket end cap is manufactured by the manufacturing method. Preferably, the end cap is of a multi-layer composite structure, and an exhaust channel structure for communicating between layers is arranged in the end cap. Compared with the prior art, the invention has the beneficial effects that: 1) Adopting a low-volatile hot-melt phenolic resin system to reduce the source of internal gas from a material source; 2) An ex