Ribbed composite skirt structure

Abstract

The utility model provides a reinforced composite material skirt structure, which relates to the technical field of rocket engines, and comprises a skirt body composed of a skirt flange and a skirt side wall, and the skirt side wall is integrally connected to the outer edge of the skirt flange and extends towards the back of the skirt flange; the plurality of reinforced blocks are arranged on the back surface of the skirt flange; skirt through holes are formed in the skirt flanges and the reinforced blocks in a penetrating mode, and threaded sleeves are fixedly arranged in the skirt through holes. The skirt body and the reinforced blocks are made of carbon fiber composite materials. Compared with a skirt structure of a traditional rocket engine combustion chamber shell, the skirt structure has the advantages that a metal corner box in the prior art is replaced with the stiffened blocks and the threaded sleeves, the skirt body, the stiffened blocks and the threaded sleeves are integrally made of the carbon fiber composite materials and are fixed through glue joint, the procedure of threaded connection is omitted, and the forming difficulty is greatly reduced. The stiffened blocks can ensure the structural strength and rigidity of the skirt body structure, and the weight of a formed product can be reduced by 15% compared with that of a traditional skirt body.

Description

Technical Field

[0001] The utility model relates to the technical field of rocket engines, and particularly to a reinforced composite skirt structure. Background Art

[0002] Due to its excellent properties such as low specific gravity, high specific strength and high specific modulus, composite materials have been widely used in the manufacture of the combustion chamber shell of solid rocket engines.

[0003] The combustion chamber shell is composed of front and rear joints, front and rear skirts, a fiber winding layer and an inner insulation layer. The front and rear skirts of the existing combustion chamber shell are generally composed of a composite skirt and a metal corner box. The composite skirt and the metal corner box are fixed by means of adhesive bonding plus threaded connection. The metal corner box plays a role in improving the structural strength and connecting other components. The forming difficulty is great and it cannot fully meet the lightweight requirements of rocket engines.

[0004] In view of this, how to provide a front and rear skirt structure that reduces the forming difficulty and realizes the lightweight of rocket engines is an urgent problem to be solved by those skilled in the art. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a reinforced composite skirt structure to solve the problems existing in the prior art.

[0006] To achieve the above purpose, the utility model provides a reinforced composite skirt structure, including:

[0007] A skirt body, which is composed of a skirt flange and a skirt side wall. The skirt side wall is integrally connected to the outer edge of the skirt flange and extends towards the back surface of the skirt flange;

[0008] A plurality of reinforcing blocks, which are arranged on the back surface of the skirt flange; skirt through holes are provided through the skirt flange and the reinforcing blocks, and a screw sleeve is fixedly arranged in the skirt through holes; the skirt body and the reinforcing blocks are made of carbon fiber composite materials.

[0009] Further, the thickness of the skirt side wall increases from the position far away from the skirt flange to the position close to the skirt flange, and a plurality of crack arrest grooves are provided through the inner and outer surfaces of the skirt side wall.

[0010] Further, a plurality of the reinforcing blocks are arranged circumferentially on the back surface of the skirt flange, and adjacent reinforcing blocks are connected by connecting blocks.

[0011] Further, the reinforcing block is an arc-shaped block, and the reinforcing block protrudes towards the skirt side wall and is in contact with the inner surface of the skirt side wall.

[0012] Further, the skirt through hole is a stepped hole, and the screw sleeve is adapted to the shape of the skirt through hole and is fixed in the skirt through hole by adhesive bonding.

[0013] Further, one end of the screw sleeve is located on the front surface of the skirt flange, and an internal thread hole is provided at one end of the screw sleeve.

[0014] The present utility model also provides a preparation method for a reinforced composite skirt structure for preparing the reinforced composite skirt structure, including the following steps:

[0015] S1: Prepare a male mold adapted to the shapes of the skirt body and the reinforcing blocks, and apply a release agent.

[0016] S2: Cut the prepreg and cut it by an automatic cutting machine.

[0017] S3: Manually lay it on the male mold.

[0018] S4: Enclose to form a mold, place the mold in a autoclave for curing, the curing pressure is 0.6 - 0.8 MPa, first cure at a temperature of 130 °C for 1 h, then cure at a temperature of 180 °C for 3 h; cool down to below 60 °C and take out of the furnace.

[0019] S5: Demold, and remove the reinforced composite skirt structure from the mold.

[0020] S6: Machine the reinforced composite skirt structure by a numerical control machine tool to form skirt through holes and crack arrest grooves.

[0021] S7: Machine a screw sleeve by a numerical control machine tool, and perform anodizing treatment on the screw sleeve.

[0022] S8: Sandblast the connecting surface of the screw sleeve and the skirt through hole.

[0023] S9: Bond the screw sleeve in the skirt through hole with structural adhesive and cure it at room temperature.

[0024] The present utility model discloses the following technical effects:

[0025] Compared with the skirt structure of the traditional rocket engine combustion chamber shell, in this application, the reinforcing blocks and the screw sleeve are used to replace the metal angle box in the prior art, and the skirt body and the reinforcing blocks are integrally made of carbon fiber composite material. The screw sleeve is fixed by bonding, omitting the process of threaded connection, and greatly reducing the forming difficulty. The reinforcing blocks can ensure the structural strength and stiffness of the skirt structure, and the weight of the formed product can be reduced by 15% compared with the traditional skirt body. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 This is a schematic structural view of the present utility model;

[0028] Figure 2 This is a schematic sectional view of the present utility model;

[0029] Among them, 1 is the skirt body; 101 is the skirt flange; 102 is the skirt side wall; 103 is the crack arrest groove; 2 is the screw sleeve; 201 is the threaded hole; 202 is the hexagonal socket; 3 is the stiffening block; 4 is the connecting block. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0031] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] The embodiment of the present utility model provides a stiffened composite skirt structure, including: a skirt body 1, which is an L-shaped annular structure composed of a skirt flange 101 and a skirt side wall 102. The skirt side wall 102 is integrally connected to the outer edge of the skirt flange 101 and extends towards the back of the skirt flange 101; a plurality of stiffening blocks 3 are arranged on the back of the skirt flange 101 and are located within the skirt side wall 102; the skirt flange 101 and the stiffening blocks 3 are provided with skirt through holes, and a screw sleeve 2 is fixedly arranged in the skirt through holes. The screw sleeve 2 is made of metal material; the skirt body 1 and the stiffening blocks 3 are integrally made of carbon fiber composite material.

[0033] In this embodiment, the thickness of the skirt side wall 102 increases from the position far from the skirt flange 101 to the position close to the skirt flange 101 (non-linearly, just increasing), and a plurality of crack arrest grooves 103 are provided through the inner and outer surfaces of the skirt side wall 102. The purpose of this design is to release stress when installing the skirt body 1.

[0034] In this embodiment, a plurality of stiffening blocks 3 are arranged circumferentially on the back of the skirt flange 101, and adjacent stiffening blocks 3 are connected by a connecting block 4.

[0035] In this embodiment, the stiffening block 3 is an arc-shaped block. The stiffening block 3 protrudes towards the skirt side wall 102 and is in contact with the inner surface of the skirt side wall 102. The stiffening block 3 and the connecting block 4 are both provided with appropriate thicknesses. In this embodiment, there are eight stiffening blocks 3, and eight skirt through holes are correspondingly provided. The positions of the skirt through holes are generally located at the centers of the stiffening blocks 3.

[0036] In this embodiment, the skirt through-hole is a stepped hole. The screw sleeve 2 is adapted to the shape of the skirt through-hole and is fixed in the skirt through-hole by bonding. One end of the screw sleeve 2 is located on the front surface of the skirt flange 101. An internal threaded hole 201 is provided at one end of the screw sleeve 2, and the internal threaded hole 201 is used to connect other structures of the rocket engine combustion chamber housing. In this embodiment, the screw sleeve 2 can be fixed by bonding, while the traditional "composite skirt and metal angle box" assembly needs to be fixed by bonding plus threaded connection. This embodiment can omit the processes such as drilling and positioning required for threaded connection, and the forming process is greatly simplified. The other end of the screw sleeve 2 is located on the back surface of the skirt flange 101, and an internal hexagonal hole 202 is provided at the other end of the screw sleeve 2 to facilitate the installation of the screw sleeve 2.

[0037] The embodiment of the present utility model also provides a preparation method for a reinforced composite skirt structure, which is used to prepare a reinforced composite skirt structure, and includes the following steps:

[0038] S1: Prepare a male mold adapted to the shape of the skirt body 1 and the reinforcing block 3, clean the dust and impurities on the surface, and apply a release agent after cleaning is completed;

[0039] S2: Cut the prepreg. To ensure the accuracy of the cutting shape and size of the prepreg, when cutting the prepreg, an electronic cutting drawing is made in advance and cut by an automatic cutting machine;

[0040] S3: Manually lay up on the male mold; perform manual lay-up on the mold according to the drawing. Before each layer of lay-up, check the surface state of the prepreg to see if it is complete; during lay-up, lay up layer by layer, check layer by layer, and record layer by layer. Each layer should be accurately in place without "bridging", "folding", "entrapping air" and "bringing in sundries". During the lay-up process, vacuum pre-compaction should be carried out according to the required number of layers;

[0041] S4: Seal to form a mold, use auxiliary materials such as a non-porous isolation film and a breather felt for sealing, and then put the mold into a autoclave for curing. The curing pressure is 0.6 - 0.8 MPa. First, cure at a temperature of 130 °C for 1 h, and then cure at a temperature of 180 °C for 3 h; cool down to below 60 °C and take out of the furnace;

[0042] S5: Demold, remove the integrally formed reinforced composite skirt structure (skirt body 1 and reinforcing block 3) from the mold;

[0043] S6: Machine the reinforced composite skirt structure by a numerically controlled machine tool to form a skirt through-hole and a crack arrest groove 103;

[0044] S7: Machine a metal bar to make a screw sleeve 2. Machine the threaded hole 201, the stepped outer shape and the internal hexagonal hole 202 of the screw sleeve 2 to meet the design requirements according to the drawing, and then perform anodizing treatment on the screw sleeve 2;

[0045] S8: Sandblast the connection surface between the screw sleeve 2 and the skirt through-hole;

[0046] S9: Glue the screw sleeve 2 in the skirt through-hole with structural adhesive and leave it at room temperature for curing.

[0047] After testing, the weight of the stiffened composite skirt structure prepared in this embodiment is about 47 kg, and the weight of the "composite skirt and metal corner box" assembly in the prior art is about 55 kg, which can reduce the weight by 15%. The essence of weight reduction lies in that the stiffening block 3 made of carbon fiber composite material + the screw sleeve 2 made of metal material is lighter than the weight of the metal corner box.

[0048] Conduct axial compression tests on the "composite skirt and metal corner box" assembly of the same size and the stiffened composite skirt structure prepared in this embodiment. The results show that the maximum bearing pressure of the "composite skirt and metal corner box" assembly is about 320T, and the maximum bearing pressure of the stiffened composite skirt structure is about 400T. That is to say, while reducing the weight, this embodiment can also improve the structural strength and stiffness.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0050] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A reinforced composite skirt structure, characterized in that, Comprising: A skirt body (1), which is composed of a skirt flange (101) and a skirt side wall (102). The skirt side wall (102) is integrally connected to the outer edge of the skirt flange (101) and extends towards the back direction of the skirt flange (101); A plurality of stiffening blocks (3), which are arranged on the back of the skirt flange (101); a skirt through hole is formed through the skirt flange (101) and the stiffening blocks (3), and a screw sleeve (2) is fixedly arranged in the skirt through hole; the skirt body (1) and the stiffening blocks (3) are made of carbon fiber composite materials.

2. The stiffened composite skirt structure according to claim 1, wherein The thickness of the skirt side wall (102) increases from the position far away from the skirt flange (101) to the position close to the skirt flange (101), and a plurality of crack arrest grooves (103) are formed through the inner and outer surfaces of the skirt side wall (102).

3. The stiffened composite skirt structure according to claim 2, characterized in that, The plurality of stiffening blocks (3) are arranged on the back of the skirt flange (101) along the circumferential direction, and adjacent stiffening blocks (3) are connected by a connecting block (4).

4. The stiffened composite skirt structure according to claim 3, characterized in that, The stiffening block (3) is an arc-shaped block, and the stiffening block (3) protrudes towards the skirt side wall (102) and is in contact with the inner surface of the skirt side wall (102).

5. The stiffened composite skirt structure according to claim 4, wherein The skirt through hole is a stepped hole, and the screw sleeve (2) is adapted to the shape of the skirt through hole and is fixedly glued in the skirt through hole.

6. The stiffened composite skirt structure according to claim 5, wherein One end of the screw sleeve (2) is located on the front surface of the skirt flange (101), and an internal thread hole (201) is arranged at one end of the screw sleeve (2).

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