A method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section
By winding the initial insulation layer blank onto the nozzle diffuser section winding mold and selecting the part to be formed, and using the forming skin to fix the surface and cure, the problem of difficult control of carbon layer thickness is solved, and the stability and ablation resistance of carbon layer are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUBEI SANJIANG AEROSPACE GRP HONGYANG ELECTROMECHANICAL
- Filing Date
- 2023-12-21
- Publication Date
- 2026-05-26
AI Technical Summary
In existing technologies, the thickness of the carbon layer in the nozzle diffuser section is difficult to control, resulting in obvious peaks and troughs in the carbon layer, which affects the engine's operational stability and the missile's flight performance.
By winding the initial insulation layer blank onto the winding mold, selecting the part to be formed for carbon layer control, using the forming skin to fix it to the surface of the part to be formed, forming a vacuum assembly and curing it, homogenizing the carbon layer wrinkles, and controlling the carbon layer thickness.
The stability of the carbon layer was improved, ensuring the ablation resistance stability of the insulation layer in the diffuser section and improving the forming quality of the nozzle diffuser section.
Smart Images
Figure CN117507329B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of aerospace technology, and in particular to a method for controlling the thickness of the carbon layer in the heat insulation layer of the nozzle diffuser section. Background Technology
[0002] The diffuser insulation layer blank (hereinafter referred to as the diffuser section) of the engine nozzle is composed of a composite material system of polyacrylonitrile-based carbon fiber cloth / phenolic-high silica glass fiber cloth / phenolic. It is an important component of the engine nozzle, located at the tail of the combustion chamber, and provides a channel for the expansion of combustion gases. The quality of the diffuser section has a significant impact on the overall performance of the engine. The ablation resistance stability of the diffuser insulation layer depends on the quality of the carbon layer. Poor carbon layer stability can lead to engine failure and missile flight failure. In related technologies, the carbon layer thickness is difficult to control after the diffuser section is cured. Higher curing pressure can cause large wrinkles in the carbon layer, resulting in more obvious peaks and troughs in the carbon layer. Summary of the Invention
[0003] This application provides a method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section, which to some extent solves the technical problem that the thickness of the carbon layer is difficult to control after the diffuser section is cured in related technologies.
[0004] This application provides a method for controlling the thickness of the carbon layer in the insulation layer of a nozzle diffuser section, comprising:
[0005] The initial insulation layer blank of the nozzle diffuser section is wound onto a winding mold to form the shape;
[0006] Select the portion of the initial insulation layer blank to be formed;
[0007] The shaped skin is fixed to the surface of the part to be shaped;
[0008] The winding mold, which contains the initial insulation layer blank and the forming skin, is placed in a vacuum sleeve, vacuumed, and cured to form the target insulation layer blank.
[0009] The target insulation layer blank is precision machined to obtain the nozzle diffuser section insulation layer.
[0010] In some embodiments, the step of selecting the portion of the initial insulation blank to be formed includes:
[0011] The smaller end of the initial insulation layer blank is selected as the part to be formed.
[0012] In some embodiments, the length of the small end of the initial insulation layer blank is less than or equal to 400 mm, and the inner diameter is less than or equal to 100 mm.
[0013] In some embodiments, the step of fixing the molding skin to the surface of the portion to be molded includes:
[0014] The initial skin is shaped to make its shape match the shape of the part to be shaped.
[0015] The initial skin is cut into multiple first skin blocks and second skin blocks; wherein the number of first skin blocks and second skin blocks is the same, and the thickness of the first skin block is greater than the thickness of the second skin block, and the width of the first skin block is greater than the width of the second skin block.
[0016] The first skin block and the second skin block are processed;
[0017] The first skin block and the second skin block are fixed to the surface of the part to be formed to form the shaped skin; wherein the first skin block and the second skin block are arranged alternately.
[0018] In some embodiments, the thickness of the first skin block is 1.3mm-1.6mm, and the thickness of the second skin block is 0.8mm-1.1mm.
[0019] In some embodiments, the step of processing the first skin block and the second skin block includes:
[0020] Multiple through holes are drilled in the first skin block and the second skin block;
[0021] The sharp corners of the first skin block and the second skin block are machined into chamfers.
[0022] In some embodiments, the diameter of the through holes on the first skin block and the second skin block is 2mm-4mm, and the interval between two adjacent through holes is 4mm-6mm.
[0023] In some embodiments, the step of fixing the first skin block and the second skin block to the surface of the portion to be formed to form the shaped skin includes:
[0024] Place the first skin block and the second skin block on the surface of the part to be formed;
[0025] The first skin block and the second skin block are wrapped and fixed to the surface of the part to be formed using alkali-free glass cloth.
[0026] In some embodiments, the step of placing the winding mold, in which the initial insulation layer blank and the forming skin are disposed, into a vacuum bag, evacuating and curing it to form the target insulation layer blank includes:
[0027] A vacuum assembly is formed by sequentially covering the outer surface of the molded skin with an adhesive-absorbing material and a vacuum sleeve, and connecting a vacuum line to the vacuum sleeve to evacuate the vacuum sleeve.
[0028] The vacuum component is placed in a hydraulic autoclave for curing to form the target insulation layer blank.
[0029] In some embodiments, the material of the molded skin is fiberglass.
[0030] The beneficial effects of this application are as follows:
[0031] This application provides a method for controlling the carbon layer thickness of the insulation layer in the diffuser section of a nozzle. After the initial insulation layer blank of the diffuser section is wound onto a winding mold and formed, the part of the initial insulation layer blank to be formed is selected, and the forming skin is fixed to the surface of the part to be formed. Therefore, when the winding mold with the initial insulation layer blank and the forming skin is placed in a vacuum sleeve for vacuuming and curing, the curing pressure is first transmitted to the forming skin. During the curing process, the forming skin shrinks along with the surface of the diffuser section, which has the effect of homogenizing the carbon layer wrinkles and controlling the carbon layer thickness, thereby improving the stability of the carbon layer and ensuring the ablation resistance stability of the insulation layer of the diffuser section. Attached Figure Description
[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.
[0033] Figure 1 This is a schematic diagram of the structure of the target insulation layer blank provided in the embodiments of this application.
[0034] Figure 2 for Figure 1 A schematic diagram of the structure of the first or second skin block.
[0035] Explanation of reference numerals in the attached figures:
[0036] 100 - Target insulation layer blank, 110 - Initial insulation layer blank, 120 - Formed skin, 121 - First skin block, 122 - Second skin block, 123 - Through hole. Detailed Implementation
[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0038] It should be noted that all directional indications in the embodiments of the present invention are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.
[0039] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0040] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.
[0041] Combination Figure 1 and Figure 2 This application provides a method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section, which improves the difficulty in controlling the thickness of the uniform carbon layer after curing in related technologies. The method includes:
[0042] S1: The initial insulation layer blank 110 of the nozzle diffuser section is wound onto the winding mold to form a shape.
[0043] The shape of the winding mold is the target shape after the nozzle diffuser section is formed. The initial insulation layer blank 110 of the nozzle diffuser section is wound onto the winding mold to form a shape, in order to prepare for the subsequent processing of the initial insulation layer blank 110 into the insulation layer of the nozzle diffuser section.
[0044] S2: Select the part of the initial insulation layer blank 110 to be formed.
[0045] Since the carbon layer thickness in the initial insulation layer blank 110 is not entirely difficult to control, controlling the carbon layer of the entire initial insulation layer blank 110 would result in material waste and increase the workload of the operators. Therefore, it is only necessary to select the part of the initial insulation layer blank 110 with more obvious carbon layer peaks and valleys for subsequent carbon layer control. This part is the part to be formed.
[0046] In some embodiments, the step of selecting the portion to be formed from the initial insulation blank 110 includes:
[0047] Select the small end of the initial insulation layer blank 110 as the part to be formed.
[0048] The nozzle diffuser section has a small end and a large end. Similarly, the initial insulation layer blank 110 after winding also has a small end and a large end. When the engine is running, the small end of the nozzle diffuser section, near the flame, experiences the most severe ablation. Therefore, the carbon layer thickness at the small end is designed to be thicker, while the carbon layer thickness at the large end is designed to be thinner. Generally, the carbon layer thickness at the small end is greater than or equal to 15mm, and the carbon layer thickness at the large end is 3mm to 6mm. Because the inner diameter of the small end is smaller and the circumferential curvature is larger, the carbon layer shrinks more significantly after winding and curing, making it easier to generate larger peaks and troughs. Conversely, because the carbon layer at the large end is thinner and has a larger diameter, the peaks and troughs are less pronounced after winding and curing; therefore, only the carbon layer at the small end needs to be controlled. Specifically, the length of the small end of the initial insulation layer blank 110 is less than or equal to 400mm, and the inner diameter is less than or equal to 100mm.
[0049] S3: Fix the forming skin 120 to the surface of the part to be formed.
[0050] The shaped skin 120 has the same shape as the part to be shaped in the initial insulation layer blank 110, so that the shaped skin 120 can fit with the surface of the part to be shaped. During subsequent curing, the curing pressure will be transmitted to the shaped skin 120 first. During the curing process, the shaped skin 120 shrinks along with the surface of the part to be shaped, which can homogenize the carbon layer wrinkles and control the carbon layer thickness, thereby improving the stability of the carbon layer and ensuring the ablation resistance stability of the diffusion section insulation layer.
[0051] In some embodiments, the step of securing the molding skin 120 to the surface of the portion to be molded includes:
[0052] S31: Perform a molding design on the initial skin so that the shape of the initial skin matches the shape of the part to be molded.
[0053] Matching the initial skin shape to the shape of the part to be formed ensures a close fit between the initial skin and the surface of the part, thus guaranteeing effective control of the subsequent carbon layer. Specifically, the initial skin can be made by laying alkali-free glass fiber or barium phenolic resin prepreg on a winding mold, vacuum curing it, and then removing it from the winding mold.
[0054] Since the initial skin needs to be processed later, and the molded skin 120 needs to withstand curing pressure, the initial skin needs to be made of a material that has both a certain strength and good processability, such as fiberglass.
[0055] S32: Cut the initial skin into multiple first skin blocks 121 and second skin blocks 122; wherein the number of first skin blocks 121 and second skin blocks 122 is the same, and the thickness of the first skin block 121 is greater than the thickness of the second skin block 122, and the width of the first skin block 121 is greater than the width of the second skin block 122.
[0056] The number of the first skin block 121 and the second skin block 122 can be set according to the actual situation. Specifically, in this embodiment, both the first skin block 121 and the second skin block 122 can be 4 pieces.
[0057] S33: Process the first skin block 121 and the second skin block 122.
[0058] During the curing of the diffusion section, a chemical reaction occurs, and small molecule gases and water need to be discharged. At the same time, the curing shrinkage of the diffusion section will also discharge some resin. Since the first skin block 121 and the second skin block 122 will cover the outside of the initial insulation layer blank 110 in subsequent steps, in order not to affect the discharge of substances, the first skin block 121 and the second skin block 122 need to be processed before being assembled onto the initial insulation layer blank 110.
[0059] In some embodiments, the steps of processing the first skin block 121 and the second skin block 122 include:
[0060] S331: Drill multiple through holes 123 on the first skin block 121 and the second skin block 122.
[0061] After multiple through holes 123 are drilled on the first skin block 121 and the second skin block 122, it is convenient for substances such as resin and gas to be discharged. Specifically, the diameter of the through holes 123 on the first skin block 121 and the second skin block 122 is 2mm-4mm, and the interval between two adjacent through holes 123 is 4mm-6mm.
[0062] S332: The sharp corners of the first skin block 121 and the second skin block 122 are machined into chamfers.
[0063] Since the molded skin 120 will be placed in a vacuum sleeve for curing, the sharp corners of the first skin block 121 and the second skin block 122 are chamfered to prevent the sharp parts of the molded skin 120 from puncturing the vacuum sleeve during the curing process.
[0064] S34: Fix the first skin block 121 and the second skin block 122 to the surface of the part to be formed to form a shaped skin 120; wherein the first skin block 121 and the second skin block 122 are arranged alternately.
[0065] The thicker first skin block 121 is the main part controlling the thickness of the carbon layer. Without the formed skin 120, the initial insulation layer blank 110 will exhibit numerous and large wrinkles in the circumferential direction during curing and compression. However, after the formed skin 120 is wrapped around the outside of the initial insulation layer blank 110, the thicker and more rigid first skin block 121 ensures that the portion of the initial insulation layer blank 110 with the first skin block 121 will not develop many wrinkles. Furthermore, because the width of the first skin block 121 is greater than that of the second skin block... The width of block 122, i.e., in the formed skin 120, means that the overall size of the first skin block 121 is much larger than the overall size of the second skin block 122. This ensures that most areas on the initial insulation layer blank 110 will not have many wrinkles. Since the second skin block 122 is thinner and less rigid, the wrinkles are mainly concentrated in the area on the initial insulation layer blank 110 where the second skin block 122 is placed. In other words, the placement of the second skin block 122 leaves space for wrinkle formation, so as not to affect the curing and compression of the initial insulation layer blank 110. However, because the overall size of the second skin block 122 is smaller, it ensures that only a few areas on the initial insulation layer blank 110 have wrinkles. This allows for control of the carbon layer thickness during curing, homogenizes wrinkles caused by carbon layer shrinkage, improves the problem of difficult-to-control carbon layer thickness in small-sized diffusion sections, and improves the forming quality of the diffusion section.
[0066] Meanwhile, the arrangement of multiple first skin blocks 121 and second skin blocks 122 will also disperse the single large peaks and valleys formed when there is no formed skin 120 into multiple small peaks and valleys through multiple first skin blocks 121 and second skin blocks 122, which can further play the role of controlling the thickness of the carbon layer.
[0067] The first skin block 121 and the second skin block 122 are staggered, that is, every two adjacent first skin blocks 121 are spaced apart, and the second skin block 122 is placed between two adjacent first skin blocks 121, so that the distribution of wrinkles is more uniform and the wrinkles are mainly concentrated in the area on the initial insulation layer blank 110 where the second skin block 122 is placed.
[0068] Specifically, the thickness of the first skin block 121 is 1.3mm-1.6mm, and the thickness of the second skin block 122 is 0.8mm-1.1mm.
[0069] In some embodiments, the step of fixing the first skin block 121 and the second skin block 122 to the surface of the portion to be formed to form the molded skin 120 includes:
[0070] The first skin block 121 and the second skin block 122 are placed on the surface of the part to be formed, and the first skin block 121 and the second skin block 122 are wrapped and fixed to the surface of the part to be formed using alkali-free glass cloth.
[0071] S4: The winding mold with the initial insulation layer blank 110 and the forming skin 120 set is placed in a vacuum sleeve, vacuumed and cured to form the target insulation layer blank 100.
[0072] Since the initial insulation layer blank 110 is covered with the shaped skin 120, the curing pressure will be transmitted to the shaped skin 120 first during the curing process. The shaped skin 120 shrinks together with the surface of the diffusion section during the curing process, which can homogenize the carbon layer wrinkles and control the carbon layer thickness, thereby improving the stability of the carbon layer and ensuring the ablation resistance stability of the insulation layer of the diffusion section.
[0073] Of course, the material of the molded skin 120 is also fiberglass.
[0074] In some embodiments, the step of placing the winding mold, in which the initial insulation layer blank 110 and the forming skin 120 are set, into a vacuum bag, evacuating and curing it to form the target insulation layer blank 100 includes:
[0075] A vacuum assembly is formed by sequentially covering the outer surface of the molded skin 120 with adhesive-absorbing material and a vacuum sleeve, and connecting the vacuum pipeline to the vacuum sleeve to evacuate the vacuum sleeve.
[0076] The vacuum component is placed in a hydraulic autoclave for curing to form the target insulation layer blank 100.
[0077] S5: Perform precision machining on the target insulation layer blank 100 to obtain the nozzle diffuser section insulation layer.
[0078] During the finishing process, the formed skin 120 can be removed to obtain the heat insulation layer of the nozzle diffuser section.
[0079] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.
[0080] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section, characterized in that, include: The initial insulation layer blank of the nozzle diffuser section is wound onto a winding mold to form the shape; Select the small end of the initial insulation layer blank as the part to be formed; The shaped skin is fixed to the surface of the part to be shaped; The winding mold, which contains the initial insulation layer blank and the forming skin, is placed in a vacuum sleeve, vacuumed, and cured to form the target insulation layer blank. The target insulation layer blank is precision machined to obtain the nozzle diffuser section insulation layer; The step of fixing the shaped skin to the surface of the part to be shaped includes: The initial skin is shaped to make its shape match the shape of the part to be shaped. The initial skin is cut into multiple first skin blocks and second skin blocks; wherein the number of first skin blocks and second skin blocks is the same, and the thickness of the first skin block is greater than the thickness of the second skin block, and the width of the first skin block is greater than the width of the second skin block. The first skin block and the second skin block are processed; The first skin block and the second skin block are fixed to the surface of the part to be formed to form the shaped skin; wherein the first skin block and the second skin block are arranged alternately.
2. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to claim 1, characterized in that, The length of the small end of the initial insulation layer blank is less than or equal to 400 mm, and the inner diameter is less than or equal to 100 mm.
3. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to claim 1, characterized in that, The thickness of the first skin block is 1.3mm-1.6mm, and the thickness of the second skin block is 0.8mm-1.1mm.
4. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to claim 1, characterized in that, The steps for processing the first skin block and the second skin block include: Multiple through holes are drilled in the first skin block and the second skin block; The sharp corners of the first skin block and the second skin block are machined into chamfers.
5. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to claim 4, characterized in that, The diameter of the through holes on the first skin block and the second skin block is 2mm-4mm, and the interval between two adjacent through holes is 4mm-6mm.
6. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to claim 1, characterized in that, The step of fixing the first skin block and the second skin block to the surface of the part to be formed to form the shaped skin includes: Place the first skin block and the second skin block on the surface of the part to be formed; The first skin block and the second skin block are wrapped and fixed to the surface of the part to be formed using alkali-free glass cloth.
7. The method for controlling the thickness of the carbon layer in the heat insulation layer of the nozzle diffuser section according to claim 1, characterized in that, The step of placing the winding mold, in which the initial insulation layer blank and the forming skin are set, into a vacuum bag, evacuating and curing it to form the target insulation layer blank includes: A vacuum assembly is formed by sequentially covering the outer surface of the molded skin with an adhesive-absorbing material and a vacuum sleeve, and connecting a vacuum line to the vacuum sleeve to evacuate the vacuum sleeve. The vacuum component is placed in a hydraulic autoclave for curing to form the target insulation layer blank.
8. The method for controlling the thickness of the carbon layer in the insulation layer of the nozzle diffuser section according to any one of claims 1-7, characterized in that, The material of the molded skin is fiberglass.