Ceramic matrix composite material center cone connecting structure

Abstract

The invention relates to the technical field of aero-engine design and manufacturing, and discloses a ceramic matrix composite material center cone connecting structure which is characterized in that a center cone main body made of a ceramic matrix composite material is inserted into a mounting groove of a metal mounting edge, and then a second mounting edge of the metal mounting edge is connected with an engine hot end component; the distance between the installation grooves is larger than the thickness of the inserting installation position of the center cone body, and the problem that a ceramic matrix composite material center cone structure and an engine metal component are not matched in heat can be solved. Therefore, the problems of stress concentration, abrasion, structural failure and the like which are easily caused by thermal mismatching of the metal component and the ceramic matrix composite material center cone main body in a high-temperature working environment are effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengine design and manufacturing, and discloses a central cone connection structure of a ceramic-based composite material. Background Art

[0002] With the development of design and manufacturing technology of aircraft engines and gas turbines, the cycle parameters of engines are getting higher and higher, which leads to the increase in the operating temperature of the hot end components of the engine. At the same time, aircraft engines and gas turbines are also facing the demand for structural weight reduction to reduce structural weight and improve thrust-to-weight ratio.

[0003] Ceramic-based composites are one of the best ways to solve the aforementioned engine problems, with their high temperature resistance, high specific strength and low density. However, the thermal expansion coefficients of ceramic-based composites vary greatly; at the same time, the hardness and anti-friction properties of ceramic-based composites are also different from those of metals. This means that if ceramic-based composite components adopt traditional structural designs, it will lead to serious thermal mismatch problems and friction and wear problems, which will lead to fiber exposure, component damage or even failure, affecting engine operation and safety.

[0004] From some patents, we know that the existing solutions are: 1. Solve the thermal matching problem by designing the metal into a fan shape, but the connection between the fan-shaped metal parts and other components creates new problems. At the same time, the fan-shaped structure leads to reduced sealing performance, weakened overall rigidity, and reduced connection reliability; 2. Isolate the thermal expansion of ceramic-based composites through bushings and a series of components, but the current design is too complicated and the number of added parts is too large, resulting in reduced reliability; 3. Other solutions deal with special-shaped grooves in ceramic-based composites, which may also lead to failure to meet engine strength requirements under certain working conditions. Summary of the invention

[0005] The purpose of the present invention is to provide a ceramic-based composite material center cone connection structure, which can solve the thermal mismatch problem between the ceramic-based composite material center cone structure and the engine metal components, thereby effectively avoiding the stress concentration, wear and structural failure problems easily caused by the thermal mismatch between the metal components and the ceramic-based composite material center cone body in a high-temperature working environment.

[0006] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0007] A ceramic matrix composite center cone connection structure, comprising:

[0008] A central cone body, the central cone body is made of a ceramic-based composite material, and a first mounting edge is provided on the end surface of the central cone body away from the cone portion;

[0009] A metal mounting edge, wherein one end of the metal mounting edge is provided with a second mounting edge for mounting with the engine body, and the metal mounting edge is provided with a mounting groove for inserting the first mounting edge at an end surface away from the second mounting edge, and the groove spacing of the mounting groove is greater than the thickness of the first mounting edge;

[0010] The mounting hole is arranged at a circumferential position of the metal mounting edge corresponding to the mounting groove, and a socket corresponding to the mounting hole is provided on the first mounting edge; the metal mounting edge and the first mounting edge are fixedly connected by bolts inserted into the mounting hole and the socket.

[0011] Furthermore, the nominal thickness of the first mounting edge of the central cone body is The analysis results show that T is the nominal thickness of the first mounting edge, δ is the stress concentration factor of the ceramic matrix composite material, and the value range of δ is 2 to 3. t is the cone wall thickness of the central cone body, and C v is the coefficient of variation of mechanical properties of ceramic matrix composites, C v The value range is 0.15 to 0.2.

[0012] Furthermore, the connection position between the first mounting edge and the cone is smoothly connected with a fillet of R100mm.

[0013] Furthermore, a distance sleeve is provided in the insertion hole, and the outer diameter of the distance sleeve is smaller than the diameter of the insertion hole.

[0014] Furthermore, a sealing ring is provided in the installation groove, and the sealing ring is located between a gap formed by the installation groove and the first installation edge.

[0015] Furthermore, the bolt is a countersunk bolt, and the threaded section of the bolt is provided with a self-locking nut that cooperates with the bolt.

[0016] Furthermore, the outer side wall of the mounting groove is provided with a protruding structure extending radially outward for accommodating the head of the countersunk bolt.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention inserts the central cone body of the ceramic-based composite material into the mounting groove of the metal mounting edge, and then connects the second mounting edge of the metal mounting edge to the hot end component of the engine, and the spacing between the mounting grooves is greater than the thickness of the central cone body at the plug-in installation point, which can solve the thermal mismatch problem between the central cone structure of the ceramic-based composite material and the metal components of the engine, thereby effectively avoiding the stress concentration, wear and structural failure problems easily caused by the thermal mismatch between the metal components and the central cone body of the ceramic-based composite material in a high-temperature working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the rotational cross-section structure of the central cone connection structure of the ceramic matrix composite material in the embodiment;

[0019] Figure 2 Schematic diagram of the main structure of the central cone of the ceramic matrix composite material in the embodiment;

[0020] Figure 3 This is a schematic diagram of the connection between the metal mounting edge and the center cone body in the embodiment;

[0021] Among them, 1. center cone body; 101. first mounting edge; 102. socket; 2. metal mounting edge; 201. second mounting edge; 202. mounting groove; 203. raised structure; 3. bolt; 4. distance sleeve; 5. sealing ring; 6. self-locking nut. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0023] Example

[0024] See also Figure 1-Figure 3 , a ceramic matrix composite center cone connection structure, comprising:

[0025] A central cone body 1, wherein the central cone body 1 is made of a ceramic-based composite material and a first mounting edge 101 is provided on the end surface of the central cone body 1 away from the cone portion;

[0026] A metal mounting edge 2, wherein one end of the metal mounting edge 2 is provided with a second mounting edge 201 for mounting with the engine body, and the metal mounting edge 2 is provided with a mounting groove 202 for inserting the first mounting edge 101 at an end surface away from the second mounting edge 201, and the groove spacing of the mounting groove 202 is greater than the thickness of the first mounting edge 101;

[0027] The mounting hole is arranged at a circumferential position of the metal mounting edge 2 corresponding to the mounting groove 202, and a socket 102 corresponding to the mounting hole is provided on the first mounting edge 101; the metal mounting edge 2 and the first mounting edge 101 are fixedly connected by bolts 3 inserted into the mounting hole and the socket 102.

[0028] In this embodiment, the central cone body 1 of the ceramic-based composite material is inserted into the mounting groove 202 of the metal mounting edge 2, and then the second mounting edge 201 of the metal mounting edge 2 is connected to the hot end component of the engine. The structure of the metal mounting edge 2 can be based on the specific form of the connection structure with the central cone on the specific engine, such as the cross-section of the metal mounting edge 2 using a "y"-shaped mounting groove 202 at one end and an "L"-shaped or "I"-shaped metal structure at the other end. Among them, the L-shaped or "I"-shaped end is provided with a hole structure connected to the engine, and the other end is provided with a mounting hole structure connected to the central cone body 1 of the ceramic-based composite material. The spacing of the "y"-shaped mounting groove 202 is greater than the thickness of the central cone body 1 at the plug-in installation position, which can solve the problem of thermal mismatch between the central cone structure of the ceramic-based composite material and the metal components of the engine, thereby effectively avoiding the problems of stress concentration, wear and structural failure that are easily caused by thermal mismatch between the metal components and the central cone body 1 of the ceramic-based composite material in a high-temperature working environment.

[0029] In the present embodiment, a distance sleeve 4 is also arranged in the insertion hole 102, and the outer diameter of the distance sleeve 4 is smaller than the diameter of the insertion hole 102. The distance sleeve 4 is used to protect the opening of the ceramic matrix composite material installation position, and a gap is reserved between the distance sleeve 4 and the ceramic matrix composite material opening, which ensures the thermal expansion matching between the distance sleeve 4 and the ceramic matrix composite material, and can also avoid the inner wall of the installation groove 202 of the metal installation edge 2 from exerting pressure on the ceramic matrix composite material after assembly. The distance sleeve 4 in the present embodiment is arranged along the circumference of the first installation edge 101, and the central axis of the distance sleeve 4 is parallel to the radial plane of the first installation edge 101. The distance sleeve 4 and the bolts 3 and nuts for locking can jointly form a centering structure, so that the central cone body 1 of the ceramic matrix composite material can be automatically centered after passing through the connection structure of the present embodiment. In addition, the spacing of the "y"-shaped installation groove 202 is greater than the thickness of the composite material installation position, which can avoid direct contact between the ceramic matrix composite material and the metal component, thereby further reducing the friction and wear between them.

[0030] In this embodiment, a sealing ring 5 is provided in the installation groove 202. The sealing ring 5 is located between the gap formed by the installation groove 202 and the first installation edge 101, and can seal the connection structure to ensure that the inner cavity air pressure does not leak and the high-temperature combustion gas on the outside does not enter the center cone and the inner cavity of the engine structure.

[0031] The bolt 3 in this embodiment is a countersunk bolt 3, and the threaded section of the bolt 3 is provided with a self-locking nut 6 that cooperates with the bolt 3, which can reduce the impact on the flow channel. The outer wall of the mounting groove 202 is provided with a radially outward protrusion structure 203, which can not only accommodate the head of the countersunk bolt 3, but also avoid the problem of strength reduction caused by unreasonable grooving of the mounting groove 202 position of the metal mounting edge 2, thereby ensuring the overall strength of the metal mounting edge 2.

[0032] Since the connection part is opened for connection, the stress on the edge of the hole 102 of the ceramic matrix composite material will seriously reduce the material performance, so the first installation edge 101 needs to be thickened. The analysis results show that T is the nominal thickness of the first mounting edge 101, v is the stress concentration factor of the ceramic matrix composite material, δ is in the range of 2 to 3, t is the cone wall thickness of the central cone body 1, and C v is the coefficient of variation of mechanical properties of ceramic matrix composites, C v The value range is 0.15 to 0.2. For example, the cone wall thickness of the central cone body 1 of this embodiment is 2.5 mm. The T value is calculated according to various parameters, and finally the nominal thickness T of the first mounting edge 101 is selected as 6 mm. The value of the nominal thickness of the first mounting edge 101 in this embodiment takes into account the influence of the stress concentration coefficient and the coefficient of variation of the mechanical properties of the ceramic-based composite material, and the basic thickness of the first mounting edge 101 under the perforated strip can be obtained. At the same time, the problem of low local strength of the local first mounting edge 101 caused by the large dispersion of the performance of the ceramic-based composite material is avoided, and the connection reliability between the central cone body 1 and the metal mounting edge 2 is further ensured.

[0033] In this embodiment, the connection position between the first mounting edge 101 and the cone is smoothly connected with a fillet of R100mm to reduce stress concentration caused by thickness variation.

[0034] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A central cone connection structure of a ceramic matrix composite material, characterized in that: include: A central cone body, the central cone body is made of a ceramic-based composite material, and a first mounting edge is provided on the end surface of the central cone body away from the cone portion; A metal mounting edge, wherein one end of the metal mounting edge is provided with a second mounting edge for mounting with the engine body, and the metal mounting edge is provided with a mounting groove for inserting the first mounting edge at an end surface away from the second mounting edge, wherein the groove spacing of the mounting groove is greater than the thickness of the first mounting edge; The mounting hole is arranged at a circumferential position of the metal mounting edge corresponding to the mounting groove, and a socket corresponding to the mounting hole is provided on the first mounting edge; the metal mounting edge and the first mounting edge are fixedly connected by bolts inserted into the mounting hole and the socket.

2. The central cone connection structure of the ceramic matrix composite material according to claim 1, characterized in that: The nominal thickness of the first mounting edge of the center cone body is The analysis results show that T is the nominal thickness of the first mounting edge, δ is the stress concentration factor of the ceramic matrix composite material, and the value range of δ is 2 to 3. t is the cone wall thickness of the central cone body, and C v is the coefficient of variation of mechanical properties of ceramic matrix composites, C v The value range is 0.15 to 0.

2.

3. The central cone connection structure of the ceramic matrix composite material according to claim 2, characterized in that: The connection position between the first mounting edge and the cone is smoothly connected with a fillet of R100mm.

4. The central cone connection structure of the ceramic matrix composite material according to claim 1, characterized in that: A distance sleeve is also arranged in the insertion hole, and the outer diameter of the distance sleeve is smaller than the diameter of the insertion hole.

5. The central cone connection structure of the ceramic matrix composite material according to claim 1, characterized in that: A sealing ring is arranged in the installation groove, and the sealing ring is located between the gap formed by the installation groove and the first installation edge.

6. The central cone connection structure of the ceramic matrix composite material according to claim 1, characterized in that: The bolt is a countersunk bolt, and the threaded section of the bolt is provided with a self-locking nut matched with the bolt.

7. The central cone connection structure of the ceramic matrix composite material according to claim 6, characterized in that: The outer side wall of the installation groove is provided with a protrusion structure extending radially outward for accommodating the head of the countersunk bolt.

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