Stepped variable-density ablation-resistant needling preform structure
By adopting step variable density design and needle-punching composite connection in the prefabricated body, a prefabricated body structure with an outer ablation-resistant inner layer is formed, which solves the problems of the prefabricated body not resistant to ablation and high thermal conductivity in the prior art, and achieves the effects of ablation and heat insulation.
Patent Information
- Application Number
- CN202422490508.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-15
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2034-10-15
AI Technical Summary
The existing needle-punched prefabricated body structure is not resistant to ablation and is unadjustable in the harsh environment of the aircraft, resulting in high thermal conductivity of the product and cannot meet the ablation and thermal insulation requirements of the aircraft.
Using a step variable density design, by setting multiple layers of variable density unit layers on the ablation-resistant braided layer and connecting them through needle-punching composite connections, the outer layer with ablation-resistant inner layer heat insulation prefabricated structure is formed, and the density of each unit layer is gradually reduced.
It realizes ablation resistance of the prefabricated outer layer and low thermal conductivity of the inner layer, ensuring excellent thermal insulation performance, and meeting the requirements of the aircraft in harsh environments.
Smart Images
Figure CN223224008U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of non-woven fabric weaving and needle-punched preform production, and in particular relates to a step-variable-density ablation-resistant needle-punched preform structure. Background Art
[0002] At present, with the widespread application of composite materials in aircraft, the demand for preform materials as the reinforcement structure of composite materials is increasing. At present, the needle-punched forming process of preforms is simple, the unit layer structure is consistent, and the first unit layer in contact with the airflow is not resistant to ablation, which cannot meet the requirements of aircraft in harsh environmental conditions. The specific deficiencies are as follows: (1) The structure is single. The unit layer structure of the needle-punched preform is single. Under the harsh flight environment of the aircraft, the product after the preform is formed is not resistant to ablation, which can easily cause damage to the internal structural components of the aircraft; (2) The product density is not adjustable. The unit layer structure of the needle-punched preform is consistent from the first layer to the last layer, and the density does not change. The thermal conductivity of the product after forming is relatively high.
[0003] In order to solve the above problems existing in the prior art, we propose a step-by-step density-varied ablation-resistant needle-punched preform structure. Utility Model Content
[0004] The purpose of the utility model is to provide a step-varied density ablation-resistant needle-punched preform structure.
[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a stepped variable density ablation-resistant needle-punched preform structure includes a surface ablation-resistant woven layer, on which the ablation-resistant woven layer is provided a plurality of variable density unit layers with gradually decreasing volume density, and each variable density unit layer is connected by a needle-punched composite.
[0006] Furthermore, the variable density unit layer includes five layers, namely the first density unit layer, the second density unit layer, the third density unit layer, the fourth density unit layer and the fifth density unit layer; the first density unit layer includes a layer of fiber cloth and a layer of mesh cloth stacked in sequence; the second density unit layer includes a layer of fiber cloth and two layers of mesh cloth stacked in sequence; the third density unit layer includes a layer of fiber cloth and three layers of mesh cloth stacked in sequence; the fourth density unit layer includes two layers of mesh cloth stacked in sequence; the fifth density unit layer is a layer of mesh cloth; each unit layer is compositely connected to the previous unit layer by needle punching.
[0007] Furthermore, the density of the acupuncture is 10 needles / cm 2 ~40 needles / cm 2 The density of needle punching increases with the number of needle punching layers. For each additional layer, the density of needle punching increases by 5 to 8 needles / cm. 2The structure between the unit layers drives the fibers to move up and down between the unit layers through the movement of the needle, ensuring the connection between the unit layers.
[0008] Furthermore, the ablation-resistant braided layer (1) is a quartz fiber or carbon fiber braided structure woven using a 2.5D braiding process, with a thickness of 1 mm to 10 mm, which can be adjusted according to product design requirements.
[0009] Furthermore, the fiber cloth (8) is a cloth woven from fibers, wherein the fibers are carbon fibers or quartz fibers, and the fiber cloth (8) has a thickness of 0.1-0.3 mm and a surface density of 300-350 g / cm 2 .
[0010] Furthermore, the mesh cloth (9) is a quartz mesh cloth with a thickness of 0.1-0.3 mm and a surface density of 80-120 g / cm 2 .
[0011] Compared with the prior art, the beneficial effects of the present invention are: the outer surface of the preform of the present invention is resistant to ablation, and at the same time, the unit layer of the preform is a stepped variable density needle-punched structure, which ensures that the density of the preform changes from high to low in a stepped manner from the outer layer to the inner layer. The thermal conductivity of the product is low after molding, ensuring excellent thermal insulation function. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a structural diagram of the utility model;
[0013] In the figure: 1, ablation-resistant woven layer; 2, first density unit layer; 3, second density unit layer; 4, third density unit layer; 5, fourth density unit layer; 6, fifth density unit layer; 7, acupuncture needles; 8, fiber cloth; 9, mesh cloth. DETAILED DESCRIPTION
[0014] A preferred embodiment of the present invention will be described below in conjunction with the accompanying drawings to clearly and completely describe the technical solution in the preferred embodiment of the present invention.
[0015] See Figure 1 The utility model includes a surface ablation-resistant braided layer 1, on which a plurality of variable-density unit layers with gradually decreasing volume density are arranged, and each variable-density unit layer is connected by acupuncture composite.
[0016] The variable density unit layer includes five layers, namely a first density unit layer 2, a second density unit layer 3, a third density unit layer 4, a fourth density unit layer 5 and a fifth density unit layer 6.
[0017] The first density unit layer 2 is composed of a layer of fiber cloth 8 and a layer of mesh cloth 9 stacked together and connected to the surface ablation-resistant woven layer through needle punching.
[0018] The second density unit layer 3 is formed by a layer of fiber cloth 8 and two layers of web cloth 9 stacked together and connected to the first density unit layer 2 through needle punching.
[0019] The third density unit layer 4 is formed by a layer of fiber cloth 8 and three layers of mesh cloth 9 stacked together and connected to the second density unit layer 3 through needle punching.
[0020] The fourth density unit layer 5 is formed by two layers of web fabrics 9 stacked together and connected to the third density unit layer 4 through needle punching.
[0021] The fifth density unit layer 6 is formed by a layer of mesh cloth 9 and is compositely connected with the fourth density unit layer 5 through needle punching.
[0022] The needling mechanism 7 connects the above unit layers layer by layer through needling.
[0023] The density of the needle punching is 10 needles / cm 2 ~40 needles / cm 2 The density of needle punching increases with the number of needle punching layers. For each additional layer, the density of needle punching increases by 5 to 8 needles / cm. 2 The structure between the unit layers drives the fibers to move up and down between the unit layers through the movement of the needle, ensuring the connection between the unit layers.
[0024] The ablation-resistant braided layer 1 is a quartz fiber or carbon fiber braided structure woven using a 2.5D braiding process, with a thickness of 1 mm to 10 mm, which can be adjusted according to product design requirements.
[0025] The mesh cloth 9 is a quartz mesh cloth with a thickness of 0.1-0.3 mm and a surface density of 80-120 g / cm 2 .
[0026] The different unit layer structures of the present invention are compounded together by needling through the needling mechanism 7 to form a novel stepped density ablation-resistant preform structure with an ablation-resistant outer layer and a highly efficient heat-insulating inner layer.
[0027] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A step-varied density ablation-resistant needle-punched preform structure, characterized by: The ablation-resistant braided layer (1) comprises a surface layer, on which a plurality of variable-density unit layers with gradually decreasing volume density are arranged, and the variable-density unit layers are compositely connected by needle punching.
2. The step-varied density ablation-resistant needle-punched preform structure according to claim 1, characterized in that: The variable density unit layer comprises five layers, namely a first density unit layer (2), a second density unit layer (3), a third density unit layer (4), a fourth density unit layer (5) and a fifth density unit layer (6); The first density unit layer (2) comprises a layer of fiber cloth (8) and a layer of web cloth (9) stacked in sequence; The second density unit layer (3) comprises a layer of fiber cloth (8) and two layers of web cloth (9) stacked in sequence; The third density unit layer (4) comprises a layer of fiber cloth (8) and three layers of mesh cloth (9) stacked in sequence; The fourth density unit layer (5) comprises two layers of web fabrics (9) stacked together; The fifth density unit layer (6) is a layer of mesh fabric (9); Each unit layer is compositely connected with the previous unit layer by needle punching.
3. The step-varied density ablation-resistant needle-punched preform structure according to claim 2, characterized in that: The density of the needle punching is 10 needles / cm 2 ~40 needles / cm 2 The density of needle punching increases with the number of needle punching layers. For each additional layer, the density of needle punching increases by 5 to 8 needles / cm. 2 The structure between the unit layers drives the fibers to move up and down between the unit layers through the movement of the needle, ensuring the connection between the unit layers.
4. The step-varied density ablation-resistant needle-punched preform structure according to claim 2, characterized in that: The ablation-resistant braided layer (1) is a quartz fiber or carbon fiber braided structure woven using a 2.5D braiding process, with a thickness of 1 mm to 10 mm, which can be adjusted according to product design requirements.
5. The step-varied density ablation-resistant needle-punched preform structure according to claim 2, characterized in that: The fiber cloth (8) is a cloth woven from fibers, wherein the fibers are carbon fibers or quartz fibers. The fiber cloth (8) has a thickness of 0.1-0.3 mm and a surface density of 300-350 g / cm 2 .
6. The step-varied density ablation-resistant needle-punched preform structure according to claim 2, characterized in that: The mesh cloth (9) is a quartz mesh cloth with a thickness of 0.1-0.3 mm and a surface density of 80-120 g / cm 2 .